DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio SelfLearning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the A/F sensor 1. The ECM calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual
mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up
the MIL (2 trip detection logic).
DTC No. | Trouble diagnosis name | DTC detecting condition | Possible cause |
P0171 | Fuel injection system too lean |
|
|
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDUREI
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the fuel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
NOTE: When depressing accelerator pedal threefourths (3/4) or more, the control system may not start the engine.
Do not depress accelerator pedal too much.
Does engine start?
YES >> Go to EC, "Diagnosis Procedure".
NO >> Check exhaust and intake air leak visually.
4.PERFORM DTC CONFIRMATION PROCEDUREII
Is 1st trip DTC detected?
YES >> Go to EC, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDUREIII
Hold the accelerator pedal as steady as possible.
CAUTION: Always drive vehicle at a safe speed.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC, "Diagnosis Procedure".
NO >> INSPECTION END
1.CHECK EXHAUST GAS LEAK
Is exhaust gas leak detected?
YES >> Repair or replace.
NO >> GO TO 2.
2.CHECK FOR INTAKE AIR LEAK AND PCV HOSE
Intake air leak detected?
YES >> Repair or replace.
NO >> GO TO 3.
3.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
5. Check the continuity between A/F sensor 1 harness connector or ECM harness connector and ground.
6. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
At idling: Approximately 350 kPa (3.57 kg/cm2, 51 psi)
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5. CHECK FUEL HOSES AND FUEL TUBES
Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?
YES >> Replace "fuel filter and fuel pump assembly". Refer to FL, "Exploded View".
NO >> Repair or replace
6.CHECK MASS AIR FLOW SENSOR
With CONSULT
0.8 4.0 g/s : at idling
2.0 10.0 g/s : at 2,500 rpm
With GST
0.8 4.0 g/s : at idling
2.0 10.0 g/s : at 2,500 rpm
Is the measurement value within the specification?
YES >> GO TO 7.
NO >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or grounds. Refer to EC, "DTC Logic".
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT
Without CONSULT
Clicking noise should be heard.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Perform trouble diagnosis for FUEL INJECTOR. Refer to EC, "Component Function Check".
8.CHECK FUEL INJECTOR
Keep fuel hose and all fuel injectors connected to fuel tube.
Fuel should be sprayed evenly for each fuel injector.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Replace fuel injectors from which fuel does not spray out. Always replace Oring with new ones. Refer to EM, "Removal and Installation".
9. CHECK INTERMITTENT INCIDENT
Refer to GI, "Intermittent Incident".
>> INSPECTION END
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio SelfLearning Control, the actual mixture ratio can be brought closely to the theoretical mixture ratio based on the mixture ratio feedback signal from the A/F sensor 1. The ECM calculates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual
mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up
the MIL (2 trip detection logic).
DTC No. | Trouble diagnosis name | DTC detecting condition | Possible cause |
P0172 | Fuel injection system too rich |
|
|
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDUREI
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the fuel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
NOTE: When depressing accelerator pedal threefourths (3/4) or more, the control system may not start the engine.
Do not depress accelerator pedal too much.
Does engine start?
YES >> Go to EC, "Diagnosis Procedure".
NO >> Remove spark plugs and check for fouling, etc.
4.PERFORM DTC CONFIRMATION PROCEDUREII
Is 1st trip DTC detected?
YES >> Go to EC, "Diagnosis Procedure".
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDUREIII
Hold the accelerator pedal as steady as possible.
CAUTION: Always drive vehicle at a safe speed.
4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC, "Diagnosis Procedure".
NO >> INSPECTION END
1.CHECK EXHAUST GAS LEAK
Is exhaust gas leak detected?
YES >> Repair or replace.
NO >> GO TO 2.
2.CHECK FOR INTAKE AIR LEAK AND PCV HOSE
Intake air leak detected?
YES >> Repair or replace.
NO >> GO TO 3.
3.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
6. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
At idling: Approximately 350 kPa (3.57 kg/cm2, 51 psi)
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5. CHECK FUEL HOSES AND FUEL TUBES
Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?
YES >> Replace "fuel filter and fuel pump assembly". Refer to FL, "Exploded View".
NO >> Repair or replace
6.CHECK MASS AIR FLOW SENSOR
With CONSULT
0.8 4.0 g/s : at idling
2.0 10.0 g/s : at 2,500 rpm
With GST
0.8 4.0 g/s : at idling
2.0 10.0 g/s : at 2,500 rpm
Is the measurement value within the specification?
YES >> GO TO 7.
NO >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or grounds. Refer to EC, "DTC Logic".
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT
Without CONSULT
Clicking noise should be heard.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Perform trouble diagnosis for FUEL INJECTOR. Refer to EC, "Component Function Check".
8.CHECK FUEL INJECTOR
Keep fuel hose and all fuel injectors connected to fuel tube.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Replace fuel injectors from which fuel does not spray out. Always replace Oring with new ones. Refer to EM, "Removal and Installation".
9.CHECK INTERMITTENT INCIDENT
Refer to GI, "Intermittent Incident".
>> INSPECTION END
Noise, vibration and harshness (NVH) troubleshooting
NVH troubleshooting Chart
Locate the area where noise occurs.
Confirm the type of noise.
Specify the operating condition of engine.
Check specified noise source
If necessary, repair or replace these parts.
Location
of noise
Type of
noise
Operating condition of
...
A/T Shift lock system
A/T Shift lock system : component parts
location
1 Stop lamp switch. 2 Shift lock release lever. 3 Park position switch.
4 Shift lock solenoid.
A/T Shift lock system : component description
...