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 GTS, 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
MIL
Memory
P1604
Startability Malfunction
Either of the following conditions is met (1 trip detection logic):
The engine speed is below 500 rpm with the STA signal on for a certain amount of time (refer to the illustration below).
After the engine starts (engine speed is 500 rpm or higher), the engine speed drops to 200 rpm or less within approximately 2 seconds.
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 the DTC can be stored as a result of certain user actions, even if the DTC is output, if the customer makes no mention of problems, clear the DTC 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 GTS. 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.
When confirming the 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 a 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 an ECM may be malfunctioning.
All engine speeds recorded in the freeze frame data are between 60 and 250 rpm (the engine cranks but there is no combustion).
Tip:
If the engine speed is between 60 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 #1 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 turn off.
Tip:
If the engine stalls after starter turn off, the air fuel ratio may be incorrect or the VVT may have a problem returning.
The initial combustion and starter turn off occur late.
Tip:
If the initial combustion and starter turn off 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 fuel pressure regulator failing to maintain the fuel pressure.
When 15 to 120 minutes have elapsed after stopping the engine: Problem with injector fuel seal.
When a long time has elapsed after stopping the engine: Fuel 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 to 9
60 to 250 rpm (engine cranks but no initial combustion*1)
Fuel pump control system
Ignition system
Engine coolant temperature sensor
Fuel injection system
10 to 14
250 rpm or higher (combustion occurs but initial combustion and starter turn off*2 occur late)
Engine assembly (compression loss)
Fuel injection system
Fuel pump control system
15 to 23
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
26 to 31
Starting system
Starter assembly (includes pinion gear wear or tooth damage)
Starting system
Engine assembly
Engine assembly (excess friction)
Drive plate and ring gear sub-assembly wear or tooth damage
Cranking speed too low
Battery malfunction
Battery fully depleted
32 to 34
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 fuel pressure regulator malfunction
Fuel injector assembly leak
Fuel leak from fuel line
Fuel pump control system
Fuel pump
35 to 48
Ignition system malfunction
Spark plug
Crankshaft position sensor
Ignition coil assembly
Engine stalls after starter turn off
Air suction
Intake system connections
67 to 71, 92
Deposits in throttle body
Throttle with motor body assembly
VVT valve does not return properly
Camshaft timing oil control valve assembly
Mass air flow meter sub-assembly malfunction
Mass air flow meter sub-assembly
The initial combustion and starter turn off occur late
Engine coolant temperature sensor malfunction
Engine coolant temperature sensor
49 to 61, 73
Mass air flow meter sub-assembly malfunction
Mass air flow meter sub-assembly
Abnormal A/F learning value
Air fuel ratio sensor
Deviation from fuel injection characteristics
Fuel injector assembly
Wet-fouled or dry-fouled spark plug
Spark plug
Lack of fuel pressure
Fuel pressure regulator
Fuel pump
Fuel pump control system
Systems to inspect.
Troubleshooting by System
Suspected Area
Suspected Component
Procedure
Fuel system troubleshooting A
Abnormal air fuel ratio learning value
Fuel injector assembly
86 to 91, 93, 94
95 to 102
Rough idling
Crankshaft position sensor
Abnormal fuel pressure
Fuel
Fuel leak from fuel line
Fuel pump
Fuel pressure regulator
Fuel system troubleshooting B
Abnormal concentration of HC in surge tank
Purge VSV system
Fuel injector assembly
103 to 105
Fuel system troubleshooting C
Injection signal system malfunction
Fuel injector assembly
Crankshaft position sensor
Camshaft position sensor
ECM
63 to 66, 72
Intake system troubleshooting
Difference between ISC target value and opening angle when idling
Engine assembly (compression loss)
Valve timing
Engine coolant temperature sensor
ECM
83 to 85
106 to 108
Ignition system troubleshooting
Camshaft and/or crankshaft position sensor signal malfunction
Crankshaft position sensor system (including sensor installation)
Camshaft position sensor system (including sensor installation)
ECM
74 to 82
109 to 117
Note:
Inspect the fuses for circuits related to this system before performing the following procedure.
After turning engine switch on (IG) off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.
Enter the following menus: Powertrain / Engine and ECT / Data List / Primary / Immobiliser Fuel Cut.
Powertrain > Engine and ECT > Data List
Tester Display
Immobiliser Fuel Cut
Read the value displayed on the GTS.
OK
Immobiliser Fuel Cut is OFF
Tip:
If the engine is cranked immediately after reconnecting the battery cable (key verification for immobiliser system not completed), the engine cannot be started. Key verification needs to wait for several seconds after turning the engine switch on (IG).
Result
Result
Proceed to
OK
A
NG (w/ Entry and Start System)
B
NG (w/o Entry and Start System)
C
B
REPAIR IMMOBILISER SYSTEM (W/ ENTRY AND START SYSTEM)
All 5 sets of freeze frame data are 0 rpm (no engine cranking at all)
Minimum voltage is less than 5 V
Battery fully depleted
A
Minimum voltage is 5 V or higher
Starter assembly malfunction
Crankshaft position sensor system
Excess engine friction
ECM
B
60 to 250 rpm (engine cranks but no initial combustion)
-
Fuel pump control system
Ignition system
Engine coolant temperature sensor
Fuel injection system
C
250 rpm or higher (combustion occurs but initial combustion and starter turnoff occur late)
-
Engine assembly
Engine coolant temperature sensor
Fuel injection system
Fuel pump control system
D
Result
Freeze Frame Data Item
Suspected Area
Proceed to
Low Rev for Eng Start
ON exists
Intake system connections
Throttle with motor body assembly
Camshaft timing oil control valve assembly
Mass air flow meter sub-assembly
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.
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.
Perform "Inspection After Repair" after replacing the engine assembly.
Difference between Coolant Temp and Intake Air is 10°C (18°F) or higher*1
Coolant Temp is 125°C (257°F) or higher, or lower than outside temperature*3 by 15°C (27°F) or more
-
Engine coolant temperature sensor
A
Other than above
All 5 sets of freeze frame data are ON
-
B
At least 1 of the 5 sets of freeze frame data is OFF
Fuel pump control system
C
Difference between Coolant Temp and Intake Air is less than 10°C (18°F) *2
-
At least 1 of the 5 sets of freeze frame data is OFF
Fuel pump control system
All 5 sets of freeze frame data are ON
-
B
Tip:
*1: A long time had not elapsed after stopping the engine.
*2: A long time had elapsed after stopping the engine.
*3: Use an actual outside temperature estimated from the Initial Intake Air Temp, Ambient Temp for A/C, and (if possible) the weather when the DTC was detected.
Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.
Difference between Coolant Temp and Intake Air is 10°C (18°F) or higher
Coolant Temp is 125°C (257°F) or higher, or lower than outside temperature*2 by 15°C (27°F) or more
-
-
Engine coolant temperature sensor
A
Other than above
-15% or less, or +15% or higher
-
Fuel pump control system
Fuel injector assembly
B
-15 to +15%
Minimum speed is 300 rpm or higher*1
Engine assembly
C
Minimum speed is below 300 rpm
Fuel system
Intake air system
D
Difference between Coolant Temp and Intake Air is less than 10°C (18°F)
-
-15% or less, or +15% or higher
-
Fuel pump control system
Fuel injector assembly
B
-15 to +15%
Minimum speed is 300 rpm or higher*1
Engine assembly
C
Minimum speed is below 300 rpm
Fuel system
Intake air system
D
Tip:
*1: Compression loss may have occurred in the engine assembly.
*2: Use an actual outside temperature estimated from the Initial Intake Air Temp, Ambient Temp for A/C, and (if possible) the weather when the DTC was detected.
Perform "Inspection After Repair" after replacing the engine assembly or engine coolant temperature sensor.
Check for foreign matter such as iron particles around the fuel pump (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.
Engine coolant temperature is 40°C (104°F) or less*1
Fuel pressure regulator
A
Engine coolant temperature is 40 to 90°C (104 to 194°F)*2
Fuel injector assembly
B
Engine coolant temperature is 90°C (194°F) or higher*3
Fuel pressure regulator
A
Tip:
*1: If the engine coolant temperature is 40°C [104°F] or less (after stopping the engine and the vehicle is not driven for a long period of time), the fuel pressure regulator may be stuck open. Attach a fuel pressure gauge and check the ability to maintain fuel pressure after stopping the engine.
*2: If the engine coolant temperature is 40 to 90°C [104 to 194°F] (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 [194°F] or higher (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 to maintain fuel pressure after stopping the engine.
There is no initial combustion (combustion does not occur even once)*1
Fuel pressure regulator fuel pressure maintenance
Fuel injector assembly leak
Fuel leak from fuel line
Fuel pump control system
Fuel pump
Spark plug
Crankshaft position sensor system
Ignition coil assembly system
C
The engine stalls after starter turn off (engine stalls immediately after the first time the engine speed increases)*2
Intake system connections
Throttle with motor body assembly
Camshaft timing oil control valve assembly
Mass air flow meter sub-assembly system
D
The initial combustion and starter turnoff occur late*3
Engine coolant temperature sensor
Mass air flow meter sub-assembly
Air fuel ratio sensor
Heated oxygen sensor
Fuel injector assembly
Spark plug
Fuel pressure regulator
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 MASS AIR FLOW METER SUB-ASSEMBLYClick here
E
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 and ring gear sub-assembly
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.
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.
Perform "Inspection After Repair" after replacing the 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.
Perform "Inspection After Repair" after replacing the engine assembly.
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 assembly 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 to maintain fuel pressure after stopping the engine.
*2: Fuel may be leaking from a fuel injector assembly.
*3: The fuel pressure regulator may not be able to maintain the fuel pressure. Attach a fuel pressure gauge and check the ability to maintain fuel pressure after stopping the engine.
*4: From step 62, perform fuel system troubleshooting C (steps 63 to 66, 72).
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 62 and perform troubleshooting for the ignition system (steps 74 to 82).
Perform "Inspection After Repair" after replacing the ignition coil assembly.
PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP / SPEED)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
w/ Fuel Pump Control ECU Assembly
Powertrain > Engine and ECT > Active Test
Tester Display
Control the Fuel Pump / Speed
w/o Fuel Pump Control ECU Assembly
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 62 and perform fuel system troubleshooting C (steps 63 to 66, 72).
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 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
Perform "Inspection After Repair" after replacing the engine coolant temperature sensor.
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 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
If the mass air flow meter sub-assembly 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 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
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 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
Result
Proceed to
OK
NG
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
READ VALUE USING GTS
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Data List / Ptrl AF Control / Long FT #1 and Atmosphere Pressure.
Powertrain > Engine and ECT > Data List
Tester Display
Atmosphere Pressure
Long FT #1
Result
Data List Item
Result
Suspected Area
Proceed to
Long FT #1
+25% or more or less than -25%
Air fuel ratio sensor (sensor 1)
Heated oxygen sensor (sensor 2)
Mass air flow meter sub-assembly
Fuel injector assembly
ECM
A
Atmosphere Pressure
80 kPa(abs) [600 mmHg(abs)] or less (when altitude is 0 m [0 ft.])
Enter the following menus: Powertrain / Engine and ECT / Utility / Learning Value Reset.
Confirm the following conditions as instructed on the screen.
- Engine switch on (IG)
- Engine stopped
- Battery voltage 9 V or higher
After confirming, select "Next" and initialize the learn value.
Tip:
If a message indicating learned value initialization failure is displayed on the screen, confirm the execution conditions, and perform learned value initialization again.
Enter the following menus: Powertrain / Engine and ECT / Data List / Ptrl AF Control / Fuel System Status #1.
Powertrain > Engine and ECT > Data List
Tester Display
Fuel System Status #1
Confirm that Fuel System Status #1 is CL.
Enter the following menus: Powertrain / Engine and ECT / Data List / Ptrl AF Control / AF Lambda B1S1.
Powertrain > Engine and ECT > Data List
Tester Display
AF Lambda B1S1
Confirm that AF Lambda B1S1 is 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 / Ptrl AF Control / AFS Voltage B1S1 and O2S B1S2.
Powertrain > Engine and ECT > Active Test
Active Test Display
Control the Injection Volume for A/F Sensor
Data List Display
AFS Voltage B1S1
O2S B1S2
Read the output voltage from the air fuel ratio sensor when increasing and decreasing the fuel injection volume.
Standard
GTS Display
Injection Volume
Specified Condition
AFS Voltage B1S1
+12.5%
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 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
Perform "Inspection After Repair" after replacing the air fuel ratio sensor.
Check if the idle speed is stable after starting the engine.
OK
Engine speed is stable.
Tip:
After replacing the fuel injector assembly or mass air flow meter sub-assembly, check if engine starting trouble occurs again. If engine starting trouble occurs, replace the ECM. If engine starting trouble still occurs, proceed to step 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
Perform "Inspection After Repair" after replacing the fuel injector assembly or mass air flow meter sub-assembly.
*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 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), 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 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
*3: Engine starting trouble may occur if the vehicle is driven extremely short distances repeatedly.
Perform "Inspection After Repair" after replacing the spark plug.
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 assembly 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 to maintain fuel pressure after stopping the engine.
*2: Fuel may be leaking from a fuel injector assembly.
*3: The fuel pressure regulator may not be able to maintain the fuel pressure. Attach a fuel pressure gauge and check the ability to maintain fuel pressure after stopping the engine.
*4: From step 62, perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
Attach a fuel pressure gauge and check the fuel pressure after stopping the engine.
Standard
147 kPa (1.5 kgf/cm2, 21 psi) or higher (5 minutes after stopping the engine)
Result
Result
Proceed to
Abnormal
A
Normal
B
*1
Tip:
If the engine cannot be started, read the values after cranking the engine.
*1: From step 62, perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), 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
4000 ppm or higher
A
Less than 4000 ppm
B
*1
Tip:
If the concentration is 4000 ppm or higher, a fuel injector assembly may have a sealing problem.
*1: From step 62, perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
Perform "Inspection After Repair" after replacing the fuel injector assembly.
If the malfunction could not be identified during the inspection in steps 38, 39, 40 and 46, perform fuel system troubleshooting C (steps 63 to 66, 72).
If the malfunction could not be identified during the inspection in step 44, perform ignition system troubleshooting (steps 74 to 82).
If the malfunction could not be identified during the inspection in steps 71 and 92, perform intake air system troubleshooting (steps 83 to 85). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 86 to 91, 93, 94).
If the malfunction could not be identified during the inspection in steps 49, 50, 51, 52, 55, 56, 58, 59, 60, 61 and 73, perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake air system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
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 #1 and Long FT #1 are largely different from the normal values (differ by higher 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.
Tip:
Perform "Inspection After Repair" after repairing or replacing the intake system.
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.
*1: From step 62, perform intake system troubleshooting (steps 83 to 85). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 86 to 91, 93, 94).
A
REPLACE CAMSHAFT TIMING OIL CONTROL VALVE ASSEMBLY (FOR INTAKE OR EXHAUST CAMSHAFT)
PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP / SPEED)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
w/ Fuel Pump Control ECU Assembly
Powertrain > Engine and ECT > Active Test
Tester Display
Control the Fuel Pump / Speed
w/o Fuel Pump Control ECU Assembly
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 62 and perform fuel system troubleshooting A (steps 95 to 102), fuel system troubleshooting B (steps 103 to 105), intake system troubleshooting (steps 106 to 108), and ignition system troubleshooting (steps 109 to 117), in that order.
Check if the idle speed after starting the engine is currently stable and has always been stable in the past.
Result
Problem Symptom
Suspected Area
Proceed to
Current unstable idle speed or history of unstable idle speed
Crankshaft position sensor system
A
All current and past idle 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 SENSOR INSTALLATION (CRANKSHAFT POSITION SENSOR)
Check the tightening and installation condition of the crankshaft position sensor bolt.
Check the connection of the crankshaft position sensor connector.
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 sub-assembly, check if engine starting trouble occurs again. If engine starting trouble occurs again, proceed to step 62 and perform intake system troubleshooting (steps 83 to 85). If engine starting trouble still occurs, perform fuel system troubleshooting A (steps 86 to 91, 93, 94).
Perform "Inspection After Repair" after replacing the mass air flow meter sub-assembly.
Check if the idle speed after starting the engine is currently stable and has always been stable in the past.
Result
Problem Symptom
Suspected Area
Proceed to
Current unstable idle speed or history of unstable idle speed
Crankshaft position sensor system
A
All current and past idle 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 SENSOR INSTALLATION (CRANKSHAFT POSITION SENSOR)
Check the tightening and installation condition of the crankshaft position sensor bolt.
Check the connection of the crankshaft position sensor connector.
