DESCRIPTION
| Problem Symptom | Suspected Area | Trouble Area | |
|---|---|---|---|
Strong engine vibration due to above symptoms |
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Ignition system |
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| Fuel system |
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| Intake and exhaust systems |
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| Other control systems |
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| Engine |
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| High load from another system |
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Tech Tips
If any other DTCs are output, perform troubleshooting for those DTCs first.
Make sure to reproduce the conditions present when the malfunction occurred.
Using the GTS, read the Data List to confirm the engine operating conditions. This information can be useful when troubleshooting.
If the problem symptoms do not recur, attempt to reproduce the symptoms and conditions when the malfunction occurred based on the result of the customer problem analysis. Place the priority on confirming the symptoms.
SYMPTOM AND CAUSE OF SYSTEM MALFUNCTION
Tech Tips
The following are descriptions of the characteristics of each system malfunction. After understanding the link between the causes and symptoms, perform the inspection of each component. Even if the problem symptom does not recur, signs of the malfunction may be found in the Data List.
Ignition system
| Main cause of malfunction | Performance degradation (wear, existence of foreign matter, etc.) |
| Symptom | Engine speed fluctuation due to abnormal combustion |
|
Tech Tips If the spark plug of the malfunctioning cylinder is abnormally wet with fuel, a leaking fuel injector assembly is suspected. |
|
| Main cause of malfunction | Internal malfunction |
| Problem symptom | Engine speed fluctuation due to abnormal combustion |
Fuel system
| Main cause of malfunction | Blockage |
| Problem symptom |
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| Data List |
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Tech Tips If the engine malfunction disappears when the fuel injection volume is increased or decreased using the Control the Injection Volume, the respective cylinder may be malfunctioning. |
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Tech Tips If the air fuel ratio becomes lean only when the engine is running under a high load and at a high engine speed, clogging of the fuel pump or fuel filter is suspected. |
| Main cause of malfunction |
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| Problem symptom |
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Intake and exhaust systems
| Main cause of malfunction | Performance degradation (existence of foreign matter, etc.) |
| Problem symptom | Lack of power |
| Data List | MAF |
|
Tech Tips If the value of the Data List item "MAF" is abnormal, a malfunction of the mass air flow meter sub-assembly is suspected. |
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| Main cause of malfunction | Inappropriate trim volume adjustment due to accumulation of deposits |
| Problem symptom |
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| Data List |
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| Main cause of malfunction | Deviation in sensor characteristics |
| Problem symptom | Abnormal combustion due to deviation of actual air fuel ratio from calculated ratio |
| Data List |
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Engine
| Main cause of malfunction |
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| Problem symptom |
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Tech Tips
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Data List Items Related to Lack of Power
Tech Tips
Depending on the vehicle model, the applicable Data List items may vary. Data List items other than the ones used in the diagnostic procedure are for reference only.
ISC Learning Value
ISC Flow
ISC Feedback Value
Electric Load Feedback Val
Air Conditioner FB Val
Eng Stall Control FB Flow
Short FT #1
Long FT #1
Fuel System Status #1, #2
Target Air-Fuel Ratio
AF Lambda
A/F Learn Value Idle #1
A/F Learn Value Low #1
A/F Learn Value Mid1 #1
A/F Learn Value Mid2 #1
A/F Learn Value High #1
MAF
AFS Voltage B1S1
O2S B1S1
PROCEDURE
INTERVIEW THE CUSTOMER
Interview the customer for details about the conditions when experiencing the lack of power.
Tech Tips
If a lack of power occurs when the engine is running under a high load and at a high engine speed, the fuel filter may be clogged.
| Result | ||
|---|---|---|
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| NEXT |
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CHECK DTC OUTPUT
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Perform a road test.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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GO TO DTC CHART Click here |
| A |
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SYMPTOM CONFIRMATION
Check if the problem symptoms reported in the customer problem analysis recur.
Tech Tips
If the problem symptoms do not recur, attempt to reproduce the conditions when the malfunction occurred based on the result of the customer problem analysis.
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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CHECK FOR INTERMITTENT PROBLEMS Click here |
| A |
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READ VALUE USING GTS (ISC LEARNING VALUE)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / ISC Learning Value.
| Tester Display |
|---|
| ISC Learning Value |
Read the value displayed on the GTS.
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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REMOVE FOREIGN OBJECT (CLEAN THROTTLE BODY WITH MOTOR ASSEMBLY) Click here |
| A |
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READ VALUE USING GTS (KNOCK CORRECT LEARN VALUE)
Connect the GTS to the DLC3.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Turn the GTS on.
Idle the engine.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Knock Correct Learn Value.
| Tester Display |
|---|
| Knock Correct Learn Value |
Read the value.
| Result | ||||||
|---|---|---|---|---|---|---|
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Tech Tips
If the value shown in the Data List is below 5 deg(CA), interview the customer to check if the malfunction is caused by the quality of the fuel being used.
If the result of the customer problem analysis is that improper fuel was not used or the type of fuel used is unknown, suggest that the customer refuel the vehicle with a different brand of fuel and then check if the malfunction symptoms disappear.
| B |
|
CONFIRM FUEL |
| A |
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READ VALUE USING GTS (SHORT FT AND LONG FT)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Short FT and Long FT.
Read the value displayed on the GTS.
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
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Tech Tips
"Total FT" is used to detect an abnormal air fuel ratio. As the value of "Total FT" is corrected by the ECM before it is displayed in the Data List, the displayed value may not be equal to the sum of the measured "Short FT" and "Long FT".
An abnormally lean or rich tendency can be checked by reading the following Data List items: A/F Learn Value Idle, A/F Learn Value Low, A/F Learn Value Mid1, A/F Learn Value Mid2 and A/F Learn Value High. (For vehicles equipped with a V type engine, check that both banks have the same correction tendency.) If the correction of either bank is -15% or less or +15% or more, the air fuel ratio sensor or heated oxygen sensor of that bank may be malfunctioning.
The following may cause a lean air fuel ratio (an operating range in which the air fuel ratio learned value correction is +15% or more):
Decrease in fuel injector assembly injection volume
Decrease in mass air flow meter sub-assembly output (due to existence of foreign matter)
Air leaks in intake system after mass air flow meter sub-assembly
Decrease in fuel pressure (at fuel filter, fuel pump or fuel pressure regulator assembly)
On vehicles which the learning value for each operating range can be checked, if the value of "A/F Learn Value High" only is corrected to the positive side, a malfunction in the fuel system (clogging of the fuel pump or fuel filter) is suspected.
On vehicles which the learning value for each operating range can be checked, if the value of "A/F Learn Value Idle" or "A/F Learn Value Low" only is corrected to the positive side, an air leak after the mass air flow meter sub-assembly is suspected.
The following may cause a rich air fuel ratio (an operating range in which the air fuel ratio learned value correction is -15% or less):
Increase in the fuel injector assembly injection volume
Purge VSV system
| B |
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GO TO STEP 16 Click here |
| A |
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PERFORM ACTIVE TEST USING GTS (CONTROL THE CYLINDER FUEL CUT)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine.
Tech Tips
Reproduce the vehicle conditions when the malfunction occurred (such as after the engine is warmed up or after a cold start).
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Cylinder Fuel Cut / All Data / Engine Speed.
| Active Test Display |
|---|
| Control the Cylinder Fuel Cut |
| Data List Display |
|---|
| Engine Speed |
According to the display on the GTS, perform the Active Test and check for a malfunctioning cylinder.
Tech Tips
Perform fuel-cut for each cylinder and check the change in the engine speed.
If the engine speed of a cylinder does not change while performing the Active Test, it can be determined that the cylinder is malfunctioning.
If the engine speed of all cylinders change while performing the Active Test, it can be determined that multiple cylinders are malfunctioning.
A cylinder for which the Data List item "Cylinder Misfire Count" increases may be malfunctioning.
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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READ VALUE USING GTS (MAF) Click here |
| A |
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PERFORM ACTIVE TEST USING GTS (CHECK THE CYLINDER COMPRESSION)
Tech Tips
If the vehicle does not support the Active Test "Check the Cylinder Compression", measure the compression pressure. If the compression pressure is normal, go to step 9.
Warm up the engine.
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Check the Cylinder Compression.
| Tester Display |
|---|
| Check the Cylinder Compression |
Tech Tips
To display the entire Data List, press the pull down menu button next to Primary. Then select Compression.
While the engine is not running, press the RIGHT or LEFT button to change Check the Cylinder Compression to ON.
Tech Tips
After performing the above procedure, Check the Cylinder Compression will start. Fuel injection for all cylinders is prohibited and each cylinder engine speed measurement enters standby mode.
Crank the engine for about 10 seconds.
Monitor the engine speed (Engine Speed of Cyl and Av Engine Speed of All Cyl) displayed on the GTS.
Tech Tips
At first, the GTS displays extremely high cylinder engine speed values. After approximately 10 seconds of engine cranking, each cylinder engine speed measurement will change to the actual engine speed.
Note
Do not crank the engine continuously for 20 seconds or more.
If it is necessary to crank the engine again after Check the Cylinder Compression has been changed to ON and the engine has been cranked once, press Exit to return to the Active Test menu screen. Then change Check the Cylinder Compression to ON and crank the engine.
Use a fully-charged battery.
Stop cranking the engine, and then change "Check the Cylinder Compression" to OFF after the engine stops.
Note
If the Active Test is changed to OFF while the engine is being cranked, the engine will start.
When performing the Active Test, DTC P1604 (Startability Malfunction) may be stored.
After performing the Active Test, make sure to check and clear DTCs.
Read the value.
Tech Tips
If the value of Data List item "Engine Speed of Cyl" of a cylinder is higher than other cylinders, the cylinder may be malfunctioning.
If the value of Data List item "Engine Speed of Cyl" is high for only one cylinder, compression loss is suspected.
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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CHECK CYLINDER COMPRESSION PRESSURE Click here |
| A |
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PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature 75°C (167°F) or higher with all the accessories switched off.
Idle the engine.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.
| Tester Display |
|---|
| Control the Injection Volume |
According to the display on the GTS, perform the Active Test and check the vehicle conditions when increasing and decreasing the fuel injection volume.
Tech Tips
Change the fuel injection volume between the minimum and maximum range of correction (e.g. -12.5% to 12.5%).
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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REPLACE FUEL INJECTOR ASSEMBLY Click here |
| A |
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CHECK IGNITION SYSTEM
Check the ignition system.
Tech Tips
Interchange the ignition coil assembly and spark plug of the malfunctioning cylinder with those of a known good cylinder and check if the malfunctioning cylinder returns to normal.
If the spark plug of the malfunctioning cylinder is abnormally wet with fuel even after the ignition coil assembly and spark plug are replaced, a leaking fuel injector assembly is suspected.
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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GO TO STEP 25 Click here |
| A |
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INSPECT OTHER RELATED COMPONENTS
Check the ignition coil assembly power source circuit, wire harness and connectors.
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 25 Click here |
REMOVE FOREIGN OBJECT (CLEAN THROTTLE BODY WITH MOTOR ASSEMBLY)
Clean off any deposits from the inside of the throttle body with motor assembly.
Push open the throttle valve and wipe off any carbon from the valve and bore using a piece of cloth soaked in non-residue solvent.
| *1 | Throttle Body with Motor Assembly | *2 | Bore |
| *3 | Valve | - | - |
| *a | Reference | *b | Throttle Body with Motor Assembly Cross-section Diagram |
| *c | When valve fully opened | *d | Do not directly apply cleaner |
| *e | Deposits | - | - |
Note
Make sure that the cloth or your fingers do not get caught in the valve.
Make sure that foreign matter does not enter the throttle valve.
Do not directly apply non-residue solvent to the throttle body with motor assembly or wash the throttle body with motor assembly. Cleaning solvent may leak into the motor from the shaft and cause problems such as rust or valve movement problems.
If there is coating material on the edge of the valve, be careful not to remove it.
Tech Tips
The illustrations are for reference only. Actual parts may differ.
| Result | ||
|---|---|---|
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| NEXT |
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PERFORM CONFIRMATION DRIVING PATTERN
Perform "Inspection After Repair" after cleaning the throttle body with motor assembly.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher.
Allow the engine to idle for 3 minutes or more and confirm that the engine speed is within the specified range.
Tech Tips
If the engine is operated without performing learning value reset and idle learning after cleaning the deposits from the throttle body with motor assembly, the idle speed may increase.
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 26 Click here |
CHECK CYLINDER COMPRESSION PRESSURE
Measure the cylinder compression pressure. If the compression pressure of a cylinder is low, inspect the engine assembly and repair or replace parts as necessary.
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 26 Click here |
REPLACE FUEL INJECTOR ASSEMBLY
Replace the fuel injector assembly of the malfunctioning cylinder.
Tech Tips
If the air fuel ratio learned value is corrected to the positive side for all operating ranges due to low fuel injector assembly injection volume, replace the fuel injector assemblies of all cylinders.
Perform "Inspection After Repair" after replacing the fuel injector assembly.
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 26 Click here |
READ VALUE USING GTS (MAF)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature 75°C (167°F) or higher with all the accessories switched off.
Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.
| Tester Display |
|---|
| MAF |
According to the display on the GTS, read the Data List when the engine is running.
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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CHECK INTAKE SYSTEM Click here |
| A |
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PERFORM ACTIVE TEST USING GTS (CONTROL THE INJECTION VOLUME FOR A/F SENSOR)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Start the engine and warm it up until the engine coolant temperature 75°C (167°F) or higher with all the accessories switched off.
Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.
Idle the engine.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / All Data / AFS Voltage B1S1 and O2S B1S2.
| Active Test Display |
|---|
| Control the Injection Volume for A/F Sensor |
| Data List Display |
|---|
| AFS Voltage B1S1 |
| O2S B1S2 |
According to the display on the GTS, perform the Active Test and check the vehicle conditions when increasing and decreasing the fuel injection volume.
Note
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.
Read the output voltage immediately after warming up the air fuel ratio sensor and heated oxygen sensor to avoid an inaccurate reading due to a sensor cooling.
Tech Tips
The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.
| Result | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
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| B |
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REPLACE FUEL INJECTOR ASSEMBLY Click here |
| C |
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PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP / SPEED) Click here |
| A |
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REPLACE AIR FUEL RATIO SENSOR AND HEATED OXYGEN SENSOR
Replace the air fuel ratio sensor.
Replace the heated oxygen sensor.
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 26 Click here |
REPLACE FUEL INJECTOR ASSEMBLY
Replace the fuel injector assemblies of all cylinders.
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 26 Click here |
CHECK INTAKE SYSTEM
Check for air leaks or blockage in the intake system components. If a connection problem or foreign matter is found, repair the connection or remove the foreign matter.
Tech Tips
If there is foreign matter in the intake system components, remove it before proceeding to the next step.
If there is no foreign matter in the intake system components, check for foreign matter in the mass air flow meter sub-assembly. If there is foreign matter in the mass air flow meter sub-assembly, remove it.
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 26 Click here |
PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP / SPEED)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.
| Tester Display |
|---|
| Control the Fuel Pump / Speed |
When performing the Active Test, check for an operating sound from the fuel pump.
| OK | ||||||
|---|---|---|---|---|---|---|
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| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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INSPECT FUEL PUMP CONTROL SYSTEM Click here |
| A |
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INSPECT FUEL PUMP
Attach a fuel pressure gauge and check the fuel pressure when cranking the engine and after stopping the engine.
| Standard | ||||||
|---|---|---|---|---|---|---|
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Tech Tips
If there is foreign matter such as iron particles on the fuel pump, remove it.
Make sure that there are no leaks from the fuel lines, signs of fuel leakage or fuel odors.
If the air fuel ratio becomes lean only when the engine is running under a high load and at a high engine speed, clogging of the fuel filter is suspected.
| Result | ||||||
|---|---|---|---|---|---|---|
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| B |
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INSPECT OTHER RELATED COMPONENTS Click here |
| A |
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INSPECT RELATED PARTS
Inspect the following fuel pump related parts:
Fuel pump
Fuel pressure regulator assembly
Fuel lines and connecting parts
Fuel filter
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 25 Click here |
INSPECT OTHER RELATED COMPONENTS
Inspect other related components.
Tech Tips
If the malfunctioning part could not be determined by performing the preceding inspections, one of the following malfunctions is suspected.
Deposits in the intake manifold or on an intake valve
Delay in fuel supply due to adherence of the fuel to the deposits
| Result | ||
|---|---|---|
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| NEXT |
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REPAIR OR REPLACE MALFUNCTIONING PARTS
Repair or replace the malfunctioning part.
Perform "Inspection After Repair" after repairing or replacing the malfunctioning part.
| Result | ||
|---|---|---|
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| NEXT |
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CONDUCT CONFIRMATION TEST
Check that the engine has returned to normal.
| Result | ||
|---|---|---|
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| NEXT |
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END |
INSPECT FUEL PUMP CONTROL SYSTEM
Inspect the fuel pump control system.
| Result | ||
|---|---|---|
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| NEXT |
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GO TO STEP 25 Click here |