This DTC is stored when the engine does not start even though the STA signal is input or when the engine takes a long time to start, and when the engine speed is low or the engine stalls just after the engine starts.
Using the intelligent tester, the conditions present when the DTC was stored can be confirmed by referring to the freeze frame data. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.
It is necessary to check if the vehicle ran out of fuel before performing troubleshooting, as this DTC is also stored when there is engine starting trouble due to running out of fuel.
DTC No.
Detection Item
DTC Detection Condition
Trouble Area
Warning Indicate
Memory
P1604
Startability Malfunction
Either condition is met:
The engine speed is less than 500 rpm with the STA signal on for a certain amount of time (refer to the illustration below) (1 trip detection logic).
After the engine starts (engine speed is 500 rpm or more), the engine speed drops to 200 rpm or less within approximately 2 seconds (1 trip detection logic).
Reference waveforms showing a normal cold engine start
Reference waveforms showing a normal warm engine start
Reference values when there is an air leak in the intake system during starting difficulty
Tip:
The engine started momentarily but stalled immediately after starting due to an air leak.
CAUTION / NOTICE / HINT
Tip:
In contrast to normal malfunction diagnosis for components, circuits and systems, DTC P1604 is used to determine the malfunctioning area from the problem symptoms and freeze frame data when the user mentions problems such as starting difficulty.
As these DTCs can be stored as a result of certain user actions, even if these DTCs are output, if the customer makes no mention of problems, clear these DTCs without performing any troubleshooting and return the vehicle to the customer.
If any other DTCs are output, perform troubleshooting for those DTCs first.
When the Data List item "Immobiliser Fuel Cut" is ON, the engine cannot be started.
Read freeze frame data using the intelligent tester. Freeze frame data records engine conditions when a malfunction occurs. This information can be useful when troubleshooting.
When confirming the freeze frame data, be sure to check all 5 sets of freeze frame data (Click here).
When confirming freeze frame data, if there are multiple items related to the cause of the malfunction, perform troubleshooting for all related items.
Try to start the vehicle under the conditions recorded in the freeze frame data which were present when the malfunction occurred. Confirm the data at this time and compare it with the freeze frame data.
If the malfunction does not reoccur, carefully check the vehicle conditions from when the malfunction occurred using freeze frame data.
When performing inspections, jiggle the relevant wire harnesses and connectors in an attempt to reproduce malfunctions that do not always occur.
If the same inspection or replacement procedure appears 2 times when performing an inspection procedure, it is not necessary to repeat the procedure the second time.
Malfunction Recurrence and Inspection Areas
Freeze frame data exists, but the malfunction (starting difficulty) has not reoccurred and the malfunction conditions are unknown.
The engine speed recorded in the freeze frame data is 0 rpm (the engine does not crank).
Tip:
One of the following problems may be present: battery depletion, excess engine friction, a starter malfunction or a crankshaft position sensor malfunction.
If the battery voltage is less than 6 V during cranking, there is a high probability that engine friction is abnormal.
If the battery voltage drops to 5 V or less when starting the engine, the battery may be malfunctioning.
If the battery voltage fluctuates while cranking the engine, it can be concluded that cranking is being performed. When the engine speed is 0 rpm, the crankshaft position sensor and/or ECM may be malfunctioning.
All engine speeds recorded in the freeze frame data are between 100 and 250 rpm (the engine cranks but there is no combustion).
Tip:
If the engine speed is between 100 and 250 rpm (no initial combustion), there may be a wiring problem or a complete failure of an ignition or fuel system part.
Due to an engine coolant temperature sensor malfunction, the fuel injection volume is extremely high or low and the engine may not be able to be started.
The engine speed recorded in the freeze frame data is 250 rpm or higher (the initial combustion and starter turnoff timing is too late).
Tip:
If the engine speed is 250 rpm or higher (combustion occurs but the initial combustion and starter turnoff timing is too late), the fuel injection volume is often incorrect (too low or too high) and determining the cause of the malfunction is often difficult.
Due to an engine coolant temperature sensor malfunction, the fuel injection volume is extremely high or low and engine starting trouble may occur.
If Long FT is incorrect, there may be a fuel supply problem due to the injectors or fuel pump being clogged, etc.
If the engine cranking speed is too high, compression loss may have occurred due to carbon interfering with the valve operation.
When the malfunction (starting difficulty) can be reproduced, or malfunction conditions are known, perform the following inspections ("Problem Symptoms" and "Systems to Inspect").
Problem Symptoms
The engine does not crank.
Tip:
The starter is normal if a noise that indicates the starter pinion gear is extending is heard. The battery may be fully depleted or there may be excess engine friction.
The engine cranking speed is abnormal.
Tip:
If the engine cranking speed is too high (for example, 300 rpm or higher with no combustion), compression loss may have occurred because carbon interfered with valve operation, etc.
There is no initial combustion.
Tip:
If there is no initial combustion, there is probably a wiring problem or an ignition or fuel system part malfunction.
The engine stalls after starter turnoff.
Tip:
If the engine stalls after starter turnoff, the air-fuel ratio may be incorrect or the VVT may have a problem returning.
The initial combustion and starter turnoff occur late.
Tip:
If the initial combustion and starter turnoff occur late, the fuel injection volume is probably incorrect (too low or too high).
Tip:
Causes of fuel system malfunctions according to conditions present at the time of the malfunction.
When 2 to 3 minutes have elapsed after stopping the engine: Fuel pressure loss due to the pressure regulator failing to maintain the fuel pressure.
When 15 to 120 minutes have elapsed after stopping the engine: Problem with fuel injector fuel seal.
When a long time has elapsed after stopping the engine: Pressure regulator is stuck open.
Systems to Inspect
Intake system
Ignition system
Fuel system
INSPECTION FLOW
Freeze frame data exists, but the malfunction (starting difficulty) has not reoccurred and the malfunction conditions are unknown.
Freeze Frame Data Item
Result
Suspected Area
Procedure
Engine Speed
0 rpm (no engine cranking at all)
Battery fully depleted
Engine assembly (excess friction)
Starter assembly
Immobiliser system
Crankshaft position sensor
ECM
4, 10, 12, 13, 14, 15
100 to 250 rpm (engine cranks but no initial combustion*1)
Fuel pump control system
Ignition system
Engine coolant temperature sensor
Fuel injection system
20, 21, 22, 23, 26
250 rpm or higher (combustion occurs but initial combustion and starter turnoff*2 occur late)
Engine assembly (compression loss)
Fuel injection system
Fuel pump control system
27, 35, 36, 38, 39, 41, 42, 47, 48
Tip:
*1: First combustion after cranking begins.
*2: Condition when engine speed increases and starter can be turned off.
When the malfunction (starting difficulty) can be reproduced, or when malfunction conditions are known.
Problem Symptoms
Problem Symptom
Suspected Area
Suspected Component
Procedure
The engine does not crank
Battery malfunction
Battery fully depleted
52, 53, 54, 59, 62, 63
Starting system
Starter assembly (includes pinion gear wear or tooth damage)
Starting system
Immobiliser system
Immobiliser system
Engine assembly
Engine assembly (excess friction)
Drive plate wear or tooth damage
Cranking speed too low
Battery malfunction
Battery fully depleted
53, 54, 65
Starting system
Starter assembly
Engine assembly
Engine assembly (excess friction)
Cranking speed too high
Engine assembly
Engine assembly (compression loss)
There is no initial combustion
Fuel supply problem
Cannot maintain pressure due to pressure regulator malfunction
Fuel injector leak
Fuel leak from fuel line
Fuel pump control system
Fuel pump
66 to 81
Ignition system malfunction
Spark plug
Crankshaft position sensor
Ignition coil assembly
Engine stalls after starter turnoff
Air suction
Intake system connections
82 to 90
Deposits in throttle body
Throttle body assembly
VVT valve does not return properly
Camshaft timing oil control valve assembly
Mass air flow meter malfunction
Mass air flow meter assembly
EGR valve does not close properly
EGR valve assembly
The initial combustion and starter turnoff occur late
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Immobiliser Fuel Cut.
Powertrain > Engine and ECT > Data List
Tester Display
Immobiliser Fuel Cut
Read the value displayed on the tester.
OK
Immobiliser Fuel Cut is OFF.
Tip:
After reconnecting the battery cable, if the engine is started immediately (without waiting 1.8 seconds after turning the engine switch on (IG)), the engine will stop (due to the key verification process). The engine can be started after that.
All 5 sets of freeze frame data are 0 rpm (no engine cranking at all)
Minimum voltage is below 5 V
Battery fully depleted
A
Minimum voltage is 5 V or higher
Starter malfunction
Crankshaft position sensor system
Excess engine friction
Immobiliser system
ECM
B
60 to 250 rpm (engine cranks but no initial combustion)
-
Fuel pump control system
Ignition system
Engine coolant temperature sensor
Immobiliser system
Fuel injection system
C
250 rpm or higher (combustion occurs but initial combustion and starter turnoff occur late)
-
Engine assembly
Fuel injection system
Fuel pump control system
D
When DTC P1604 is stored, either "Engine Start Hesitation"*1 or "Low Rev for Eng Start"*2 in the freeze frame data will be ON. If "Low Rev for Eng Start" is ON
E
Tip:
When DTC P1604 is stored, either "Engine Start Hesitation"*1 or "Low Rev for Eng Start"*2 in the freeze frame data will be ON. If "Low Rev for Eng Start" is ON, proceed to E.
*1: This value turns ON when the engine speed does not reach a certain value for a certain period of time when starting the engine.
*2: This value turns ON when the engine stalls immediately after starting the engine. If "Low Rev for Eng Start" is ON, as there is a possibility that the low engine speed or engine stall was caused by the user, confirm the following freeze frame data items.
If the malfunction could not be identified during the inspections in steps 69, 70, 71 and 78, perform fuel system troubleshooting C (steps 6, 7, 8, 9 and 11).
Result
Performed Step
Troubleshooting by System
Procedure
Proceed to
Steps 69, 70, 71 and 78
Fuel system troubleshooting C
6, 7, 8, 9 and 11
A
If the malfunction could not be identified during the inspection in step 76, perform ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19).
Result
Performed Step
Troubleshooting by System
Procedure
Proceed to
Step 76
Ignition system troubleshooting
9, 11, 16, 17, 18 and 19
B
If the malfunction could not be identified during the inspections in steps 86, 87, 88, 89 and 90, perform intake air system troubleshooting (steps 24, 25 and 28). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 29, 30, 31, 32, 33, 34, 37 and 40).
Result
Performed Step
Troubleshooting by System
Procedure
Proceed to
Step 86, 87, 88, 89, and 90
Intake air system troubleshooting
24, 25 and 28
C
Fuel system troubleshooting A
29, 30, 31, 32, 33, 34, 37 and 40
If the malfunction could not be identified during the inspections in steps 91, 92, 93, 94, 97, 98, 100, 101, 102, 103 and 104, perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake air system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
Minimum voltage is 6 V or higher and voltage does not fluctuate*1
Starter system
A
Minimum voltage is 6 V or higher and voltage fluctuates*2, *3
Crankshaft position sensor system
ECM
B
Minimum voltage is 5 to 6 V*4
Excess engine friction
Battery fully depleted
C
Tip:
*1: The 5 sets of freeze frame data show approximately the same battery voltage.
*2: The 5 sets of freeze frame data show different battery voltages.
*3: If the voltage fluctuates, it can be determined that cranking is being performed. When the engine speed is 0 rpm, the crankshaft position sensor system and/or the ECM may be malfunctioning.
*4: There may be excess engine friction. Make sure that the crankshaft rotates smoothly when turning it by hand. Excess engine friction may have occurred temporarily. Remove the cylinder head cover and oil pan, and check for foreign matter such as iron fragments. If there is a malfunction or signs of a malfunction present, perform a detailed inspection by disassembling all the parts.
Check for foreign matter, such as iron particles, around the fuel pump, fuel pump filter and inside the fuel tank, and for signs that the fuel pump was stuck.
Result
Result
Proceed to
There is foreign matter or signs that fuel pump was stuck
A
There is no foreign matter and no signs that fuel pump was stuck
B
Tip:
If there is foreign matter such as iron particles on the fuel pump, fuel filter or fuel tank, remove the foreign matter.
Check if the idling speed is stable after starting the engine and if an unstable idling speed has ever occurred in the past.
Result
Problem Symptom
Suspected Area
Proceed to
Current unstable idling speed or history of unstable idling speed
Crankshaft position sensor system
A
All current and past idling speeds are stable
Fuel
B
Tip:
Through the customer problem analysis, confirm the fuel being used and the location at which the fuel was added to check if the malfunction is caused by the fuel in the vehicle.
B
REPLACE FUEL
A
CHECK CRANKSHAFT POSITION SENSOR
Check the tightening and installation condition of the crankshaft position sensor bolt.
Check the connection of the crankshaft position sensor connector.
Check for foreign matter, such as iron particles, around the fuel pump, fuel pump filter and inside the fuel tank, and for signs that the fuel pump was stuck.
Result
Result
Proceed to
There is foreign matter or signs that fuel pump was stuck
A
There is no foreign matter and no signs that fuel pump was stuck
B
Tip:
If there is foreign matter such as iron particles on the fuel pump, fuel filter or fuel tank, remove the foreign matter.
*1: If the engine coolant temperature is 40°C or less (after stopping the engine and the vehicle has not been driven for a long period of time), the fuel pressure regulator may be stuck open. Attach a fuel pressure gauge and check the ability of the system to maintain fuel pressure after stopping the engine.
*2: If the engine coolant temperature is 40 to 90°C (15 to 120 minutes have passed after stopping the engine), there may be fuel leaking from a fuel injector.
*3: If the engine coolant temperature is 90°C or more (2 to 5 minutes have passed after stopping the engine), there may be a problem with the fuel pressure regulator failing to maintain the fuel pressure. Attach a fuel pressure gauge and check the ability of the fuel pressure regulator to maintain fuel pressure after stopping the engine.
Check if the idling speed is stable after starting the engine and if an unstable idling speed has ever occurred in the past.
Result
Problem Symptom
Suspected Area
Proceed to
Current unstable idling speed or history of unstable idling speed
Crankshaft position sensor system
A
All current and past idling speeds are stable
Fuel
B
Tip:
Through the customer problem analysis, confirm the fuel being used and the location at which the fuel was added to check if the malfunction is caused by the fuel in the vehicle.
B
REPLACE FUEL
A
CHECK CRANKSHAFT POSITION SENSOR
Check the tightening and installation condition of the crankshaft position sensor bolt.
Check the connection of the crankshaft position sensor connector.
OK
Sensor is installed correctly.
Result
Result
OK
NG
OK
CHECK HARNESS AND CONNECTOR (CRANKSHAFT POSITION SENSOR - ECM)Click here
There is no initial combustion (combustion does not occur even once)*1
Fuel pressure regulator fuel pressure maintenance
Fuel injector leak
Fuel leak from fuel line
Fuel pump control system
Fuel pump
Spark plug
Crankshaft position sensor system
Ignition coil system
EGR valve assembly
C
The engine stalls after starter turnoff (engine stalls immediately after the first time the engine speed increases)*2
Intake system connections
Throttle body assembly
Camshaft timing oil control valve assembly
Mass air flow meter system
EGR valve assembly
D
The initial combustion and starter turnoff occur late*3
Engine coolant temperature sensor
Mass air flow meter assembly
Air fuel ratio sensor
Heated oxygen sensor
Fuel injector assembly
Spark plug
Fuel pressure regulator assembly
Fuel pump
Fuel pump control system
E
Tip:
If there is hesitation (cranking speed is slow and combustion occurs before passing TDC) during the initial cranking period, the battery charge may be insufficient or the starter may be malfunctioning.
*1: If there is no initial combustion, a wire harness may be malfunctioning, or the ignition or fuel system may be malfunctioning.
*2: If the engine stalls after starter turnoff, the air-fuel ratio may be incorrect or the camshaft timing oil control valve may have a problem returning.
*3: If the initial combustion and starter turnoff occur late, the fuel injection volume may be incorrect (too low or too high).
INSPECT ENGINE COOLANT TEMPERATURE SENSORClick here
A
PERFORM SIMULATION TEST
When cranking the engine, check for a noise indicating that the starter pinion gear is extending, and check that the starter pinion gear is not spinning freely.
Result
Problem Symptom
Suspected Area
Proceed to
A noise indicating that the starter pinion gear is extending is heard and the starter pinion gear is not spinning freely*1
Battery
Excess engine friction
Starter assembly
A
A noise indicating that the starter pinion gear is extending is heard but the starter pinion gear is spinning freely
Drive plate
Starter assembly
B
A noise indicating that the starter pinion gear is extending is not heard
Battery
Starter assembly
Starter system
C
Tip:
*1: The battery may be fully depleted or there may be excess engine friction.
Electrolyte quantity is within the specified range.
Inspect the specific gravity.
Inspect the specific gravity of each cell.
Standard specific gravity
1.25 to 1.29 (electrolyte is at 20°C (68°F))
Tip:
If the result is not as specified, recharge or replace the battery.
It is not necessary to inspect a maintenance-free battery.
Inspect the battery voltage.
Turn the engine switch off and turn on the headlights for 20 to 30 seconds. This will remove the surface charge from the battery.
Measure the battery voltage.
Standard voltage
12.5 to 12.9 V (electrolyte is at 20°C (68°F))
Tip:
If the result is not as specified, recharge or replace the battery.
Measure the battery voltage when cranking the engine.
Standard
Approximately 6 V or higher (0°C (32°F) or higher)
Tip:
When the battery is depleted, the horn becomes quieter.
Result
Result
OK
NG
NG
CHARGE OR REPLACE BATTERY
OK
CHECK ENGINE ASSEMBLY
Check that the crankshaft rotates smoothly when rotating it by hand.
OK
Crankshaft rotates smoothly.
Tip:
Excess engine friction may have occurred temporarily. Remove the cylinder head cover and oil pan, and check for foreign matter such as iron fragments. If there is a malfunction or signs of a malfunction present, perform a detailed inspection by disassembling all the parts.
Confirm the conditions present when the malfunction occurred based on the customer problem analysis.
Result
Problem Symptom
Suspected Area
Proceed to
When the engine is stopped and a long time has passed, engine starting trouble occurs*1
Fuel pressure regulator is stuck open
A
When the engine is stopped and approximately 15 to 120 minutes have passed, engine starting trouble occurs*2
Fuel injector leak
B
When the engine is stopped and approximately 2 to 3 minutes have passed, engine starting trouble occurs*3
Failure to maintain fuel pressure by fuel pressure regulator
A
Condition other than above, or there is an inconsistency in the conditions present when engine starting trouble occurs
-
C
*4
Tip:
*1: The fuel pressure regulator may be stuck open. Attach a fuel pressure gauge and check the ability of the system to maintain fuel pressure after stopping the engine.
*2: Fuel may be leaking from a fuel injector.
*3: The fuel pressure regulator may not be able to maintain the fuel pressure. Attach a fuel pressure gauge and check the ability of the fuel pressure regulator to maintain fuel pressure after stopping the engine.
*4: From step 5, perform fuel system troubleshooting C (steps 6, 7, 8, 9 and 11).
CHECK HARNESS AND CONNECTOR (IGNITION COIL ASSEMBLY - ECM)
Disconnect the ignition coil connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Always
Tester Connection
Condition
Specified Condition
C1-2 (IGF1) - C30-6 (IGF1)
Always
Below 1 Ω
C2-2 (IGF2) - C31-5 (IGF2)
Always
Below 1 Ω
C3-2 (IGF2) - C31-5 (IGF2)
Always
Below 1 Ω
C4-2 (IGF1) - C30-6 (IGF1)
Always
Below 1 Ω
C5-2 (IGF2) - C31-5 (IGF2)
Always
Below 1 Ω
C6-2 (IGF1) - C30-6 (IGF1)
Always
Below 1 Ω
C39-2 (IGF1) - C30-6 (IGF1)
Always
Below 1 Ω
C40-2 (IGF2) - C31-5 (IGF2)
Always
Below 1 Ω
C1-2 (IGF1) or C30-6 (IGF1) - Body ground
Always
10 kΩ or higher
C2-2 (IGF2) or C31-5 (IGF2) - Body ground
Always
10 kΩ or higher
C3-2 (IGF2) or C31-5 (IGF2) - Body ground
Always
10 kΩ or higher
C4-2 (IGF1) or C30-6 (IGF1) - Body ground
Always
10 kΩ or higher
C5-2 (IGF2) or C31-5 (IGF2) - Body ground
Always
10 kΩ or higher
C6-2 (IGF1) or C30-6 (IGF1) - Body ground
Always
10 kΩ or higher
C39-2 (IGF1) or C30-6 (IGF1) - Body ground
Always
10 kΩ or higher
C40-2 (IGF2) or C31-5 (IGF2) - Body ground
Always
10 kΩ or higher
Tip:
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
Make sure there is not an excessive amount of force applied to the wire harness.
Result
Result
OK
NG
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CHECK HARNESS AND CONNECTOR (IGNITION COIL ASSEMBLY - ECM)
Disconnect the ignition coil connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Always
Tester Connection
Condition
Specified Condition
C1-3 (IGT1) - C30-24 (IGT1)
Always
Below 1 Ω
C2-3 (IGT2) - C29-27 (IGT2)
Always
Below 1 Ω
C3-3 (IGT3) - C30-27 (IGT3)
Always
Below 1 Ω
C4-3 (IGT4) - C29-26 (IGT4)
Always
Below 1 Ω
C5-3 (IGT5) - C29-25 (IGT5)
Always
Below 1 Ω
C6-3 (IGT6) - C30-28 (IGT6)
Always
Below 1 Ω
C39-3 (IGT7) - C30-26 (IGT7)
Always
Below 1 Ω
C40-3 (IGT8) - C30-25 (IGT8)
Always
Below 1 Ω
C1-3 (IGT1) or C30-24 (IGT1) - Body ground
Always
10 kΩ or higher
C2-3 (IGT2) or C29-27 (IGT2) - Body ground
Always
10 kΩ or higher
C3-3 (IGT3) or C30-27 (IGT3) - Body ground
Always
10 kΩ or higher
C4-3 (IGT4) or C29-26 (IGT4) - Body ground
Always
10 kΩ or higher
C5-3 (IGT5) or C29-25 (IGT5) - Body ground
Always
10 kΩ or higher
C6-3 (IGT6) or C30-28 (IGT6) - Body ground
Always
10 kΩ or higher
C39-3 (IGT7) or C30-26 (IGT7) - Body ground
Always
10 kΩ or higher
C40-3 (IGT8) or C30-25 (IGT8) - Body ground
Always
10 kΩ or higher
Tip:
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
Make sure there is not an excessive amount of force applied to the wire harness.
If the wire harness is normal, after replacing the ignition coil assembly, check if engine starting trouble occurs again. If engine starting trouble occurs again, proceed to step 5 and perform troubleshooting for the ignition system (steps 9, 11, 16, 17, 18 and 19).
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE FUEL PUMP / SPEED)
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
Powertrain > Engine and ECT > Active Test
Tester Display
Control the Fuel Pump / Speed
When performing the Active Test, check for fuel leakage from the fuel pipes.
Result
Result
Proceed to
Fuel leakage or signs of fuel leakage are present
A
No fuel leakage or signs of fuel leakage
B
Tip:
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
Check if the vehicle ran out of fuel, as engine starting trouble due to running out of fuel is also detected.
If there are no fuel leaks, after inspecting the fuel pump control system, check if engine starting trouble occurs again. If engine starting trouble occurs again, proceed to step 5 and perform fuel system troubleshooting C (steps 6, 7, 8, 9 and 11).
If the accelerator pedal is released after racing the engine, the inspection is easier to perform because the vacuum inside the intake manifold increases and the air suction noise becomes louder.
If Short FT and Long FT are largely different from the normal values (differ by more than 15%) when idling (intake air volume is small) and almost the same as the normal values when racing the engine (for example, when maintaining a speed of 3000 rpm) (intake air volume is high), air leakage may be present.
OK
There is no air leakage.
Result
Result
OK
NG
NG
REPAIR OR REPLACE INTAKE SYSTEM
OK
CHECK THROTTLE BODY ASSEMBLY
Disconnect the throttle body connector.
Tip:
When the connector is disconnected, the vehicle enters fail-safe mode and the throttle valve opening angle is 4 to 7°.
Crank the engine and check that it starts.
Result
Result
Proceed to
Engine starts
A
Engine does not start
B
Connect the throttle body connector.
Tip:
When this inspection is performed, the MIL may illuminate. After finishing the inspection, check and clear DTCs.
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE VVT SYSTEM)Click here
A
CHECK THROTTLE BODY ASSEMBLY
Check if carbon is in the airflow passage.
OK
No carbon present.
Result
Result
OK
NG
NG
REMOVE FOREIGN OBJECT AND CLEAN THROTTLE BODY
OK
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE VVT SYSTEM)
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Warm up the engine.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT System (Bank 1) or Control the VVT System (Bank 2).
Powertrain > Engine and ECT > Active Test
Tester Display
Control the VVT System (Bank1)
Powertrain > Engine and ECT > Active Test
Tester Display
Control the VVT System (Bank2)
Tip:
When performing the Active Test, make sure the A/C is on and the shift lever is in N.
Check the engine speed while operating the camshaft timing oil control valve using the intelligent tester.
OK
Tester Operation
Specified Condition
OFF
Normal engine speed
ON
Soon after camshaft timing oil control valve switched from OFF to ON, engine idles roughly or stalls
Tip:
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
When the results of the inspection using the Active Test are normal but the valve operating noise is abnormal, check the valve for any signs of problems.
If the camshaft timing oil control valve is stuck ON, the valve overlap increases and combustion worsens due to the internal EGR which may cause the engine to stall.
Result
Result
OK
NG
NG
REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (FOR INTAKE SIDE)
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE VVT EXHAUST LINEAR)
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Warm up the engine.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the VVT Exhaust Linear (Bank1) or Control the VVT Exhaust Linear (Bank2).
Powertrain > Engine and ECT > Active Test
Tester Display
Control the VVT Exhaust Linear (Bank1)
Powertrain > Engine and ECT > Active Test
Tester Display
Control the VVT Exhaust Linear (Bank2)
Tip:
When performing the Active Test, make sure the A/C is on and the shift lever is in N.
Check the engine speed while operating the camshaft timing oil control valve using the intelligent tester.
OK*1
Tester Operation
Specified Condition
0%
Normal engine speed
100%
Engine idles roughly or stalls
Tip:
*1: From step 5, perform intake system troubleshooting (steps 24, 25 and 28). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 29, 30, 31, 32, 33, 34, 37 and 40).Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
When the results of the inspection using the Active Test are normal but the valve operating noise is abnormal, check the valve for any signs of problems.
If the camshaft timing oil control valve is stuck ON, the valve overlap increases and combustion worsens due to the internal EGR which may cause the engine to stall.
Result
Result
OK
NG
NG
REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (FOR EXHAUST SIDE)
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)
Connect the intelligent tester to the DLC3.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tip:
When performing the Active Test, make sure the shift lever is in P or N.
The A/C switch and all accessory switches should be off.
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.
Powertrain > Engine and ECT > Active Test
Tester Display
Control the EGR Step Position
Confirm that Throttle Idle Position is ON and check the engine idling condition and the value of MAP in the Data List while performing the Active Test.
Tip:
Do not leave the EGR valve open for 10 seconds or more during the Active Test.
Be sure to return the EGR valve to step 0 when the Active Test is completed.
OK
MAP and idling condition change in response to EGR step position as follows.
Standard
-
EGR Step Position (Active Test)
Step 0
Step 0 to 30
Idling condition
Steady idling
Idling changes from steady to rough idling or engine stalls
MAP
(Data List)
20 to 40 kPa (150 to 300 mmHg)
MAP value is at least 10 kPa (75 mmHg) higher than when EGR valve is fully closed
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
Disconnect the mass air flow meter connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection
Condition
Specified Condition
C27-3 (VG) - C29-14 (VG)
Always
Below 1 Ω
C27-2 (E2G) - C29-13 (E2G)
Always
Below 1 Ω
C27-3 (VG) or C29-14 (VG) - Body ground
Always
10 kΩ or higher
Tip:
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
Make sure there is not an excessive amount of force applied to the wire harness.
If the wire harness is normal, after replacing the mass air flow meter, check if engine starting trouble occurs again. If engine starting trouble occurs again, proceed to step 5 and perform intake system troubleshooting (steps 24, 25 and 28). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 29, 30, 31, 32, 33, 34, 37 and 40).
If the engine coolant temperature sensor is malfunctioning, after replacing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
CHECK HARNESS AND CONNECTOR (ENGINE COOLANT TEMPERATURE SENSOR - ECM)
Disconnect the engine coolant temperature sensor connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection
Condition
Specified Condition
C18-2 - C30-17 (THW)
Always
Below 1 Ω
C18-1 - C29-7 (E2)
Always
Below 1 Ω
C18-2 or C30-17 (THW) - Body ground
Always
10 kΩ or higher
C18-1 or C29-7 (E2) - Body ground
Always
10 kΩ or higher
Tip:
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
Make sure there is not an excessive amount of force applied to the wire harness.
If the wire harness or connector is malfunctioning, after replacing or repairing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
Result
Result
OK
NG
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CHECK MASS AIR FLOW METER ASSEMBLY
Connect the intelligent tester to the DLC3.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Tip:
The A/C switch and all accessory switches should be off, and the shift lever should be in N or P.
Turn the tester on.
Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.
Powertrain > Engine and ECT > Data List
Tester Display
MAF
Check MAF in the Data List during idling.
Standard
3.4 to 6.2 g/sec.
Tip:
If the mass air flow meter is malfunctioning, after replacing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)
Disconnect the mass air flow meter connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection
Condition
Specified Condition
C27-3 (VG) - C29-14 (VG)
Always
Below 1 Ω
C27-2 (E2G) - C29-13 (E2G)
Always
Below 1 Ω
C27-3 (VG) or C29-14 (VG) - Body ground
Always
10 kΩ or higher
Tip:
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
Make sure there is not an excessive amount of force applied to the wire harness.
If the wire harness or connector is malfunctioning, after replacing or repairing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
Result
Result
OK
NG
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
READ VALUE USING INTELLIGENT TESTER
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Enter the following menus: Powertrain / Engine and ECT / Data List / Long FT and Atmosphere Pressure.
Enter the following menus: Powertrain / Engine and ECT / Data List / Fuel System Status #1 and Fuel System Status #2.
Powertrain > Engine and ECT > Data List
Tester Display
Fuel System Status #1
Fuel System Status #2
Confirm that Fuel System Status #1 and Fuel System Status #2 are both CL.
Enter the following menus: Powertrain / Engine and ECT / Data List / AF Lambda B1S1 and AF Lambda B2S1.
Powertrain > Engine and ECT > Data List
Tester Display
AF Lambda B1S1
AF Lambda B2S1
Confirm that AF Lambda B1S1 and AF Lambda B2S1 are both within the range of 0.95 to 1.05 when idling.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F sensor.
Powertrain > Engine and ECT > Active Test
Tester Display
Control the Injection Volume for A/F Sensor
Read the output voltage from the air fuel ratio sensor when increasing and decreasing the fuel injection volume.
Standard
Tester Display
Injection Volume
Specified Condition
AFS Voltage B1S1
AFS Voltage B2S1
+25%
Air fuel ratio sensor output voltage is below 3.1 V
-12.5%
Air fuel ratio sensor output voltage is higher than 3.4 V
Result
Result
Proceed to
Normal
A
Abnormal
B
Tip:
The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
If the air fuel ratio sensor is malfunctioning, after replacing it, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
Check if the idling speed is stable after starting the engine.
OK
Speed is stable.
Tip:
After replacing the fuel injector or mass air flow meter, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
*1: If one cylinder is abnormal, replace the spark plug of that cylinder and inspect the ignition and fuel system for that cylinder. After performing repairs, check if engine starting trouble occurs again. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
*2: If all cylinders are abnormal, replace the spark plugs of all cylinders and check if engine starting trouble occurs again. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
*3: Engine starting trouble may occur if the vehicle is driven extremely short distances repeatedly.
Confirm the conditions present when the malfunction occurred based on the customer problem analysis.
Result
Problem Symptom
Suspected Area
Proceed to
When the engine is stopped and a long time has passed, engine starting trouble occurs*1
Fuel pressure regulator is stuck open
A
When the engine is stopped and approximately 15 to 120 minutes have passed, engine starting trouble occurs*2
Fuel injector leak
B
When the engine is stopped and approximately 2 to 3 minutes have passed, engine starting trouble occurs*3
Failure to maintain fuel pressure by fuel pressure regulator
A
Condition other than above, or there is an inconsistency in the conditions present when engine starting trouble occurs
-
C
*4
Tip:
*1: The fuel pressure regulator may be stuck open. Attach a fuel pressure gauge and check the ability of the system to maintain fuel pressure after stopping the engine.
*2: Fuel may be leaking from a fuel injector.
*3: The fuel pressure regulator may not be able to maintain the fuel pressure. Attach a fuel pressure gauge and check the ability of the fuel pressure regulator to maintain fuel pressure after stopping the engine.
*4: From step 5, perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
Attach a fuel pressure gauge and check the fuel pressure after stopping the engine.
Result
Result
Proceed to
147 kPa (1.5 kgf/cm2) or higher (5 minutes after stopping the engine)
A
*1
Below 147 kPa (1.5 kgf/cm2) (5 minutes after stopping the engine)
B
Tip:
If the engine cannot be started, check the fuel pressure after cranking the engine.
*1: From step 5, perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
Clean the inside of the surge tank with compressed air.
After stopping the engine, measure the HC concentration inside the surge tank for 15 minutes.
Result
Result
Proceed to
400 ppm or more
A
Less than 400 ppm
B
*1
Tip:
If the engine cannot be started, check the fuel pressure after cranking the engine.
*1: From step 5, perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE FUEL PUMP / SPEED)
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
Powertrain > Engine and ECT > Active Test
Tester Display
Control the Fuel Pump / Speed
When performing the Active Test, check for fuel leakage from the fuel pipes.
Result
Result
Proceed to
Fuel leakage or signs of fuel leakage are present
A
No fuel leakage or signs of fuel leakage
B
Tip:
Jiggle the wire harness and connector to increase the likelihood of detecting malfunctions that do not always occur.
Check if the vehicle ran out of fuel, as engine starting trouble due to running out of fuel is also detected.
If there are no fuel leaks, after inspecting the fuel pump control system, check if engine starting trouble occurs again. If engine starting trouble still occurs, proceed to step 5 and perform fuel system troubleshooting A (steps 33, 34, 43, 44, 45, 46, 50 and 55), fuel system troubleshooting B (steps 56 to 58), intake system troubleshooting (steps 60, 61 and 64), and ignition system troubleshooting (steps 9, 11, 16, 17, 18 and 19), in that order.
Tip:
