OPERATION
- Refer to Code No. P0201 No. 1 Injector System
.
Refer to Code No. P0202 No. 2 Injector System.
Refer to Code No. P0203 No. 3 Injector System.
Refer to Code No. P0204 No. 4 Injector System.
- Refer to Code No. P0130 Cylinder 1, 4 Oxygen Sensor (Front) Circuit .
- Refer to P0150 Cylinder 2, 3 Oxygen Sensor (Front) Circuit .
FUNCTION
- The engine-A/T-ECU effects air-fuel ratio feedback control in accordance with the signals from the oxygen sensor (front).
- If the oxygen sensor (front) has deteriorated, corrections will be made by the oxygen sensor (rear).
- Diagnosis code P0125 becomes stored in memory if a failure is detected in the above air/fuel ratio feedback control system.
TROUBLE JUDGMENT
Check Conditions
- The engine coolant temperature approximately.
82°C or more.
- Within the range of air-fuel ratio feedback operation.
- Not in low speed operation.
Judgment Criterion
- The oxygen sensor output voltage is not deviated from 0.5 V for 30 seconds.
PROBABLE CAUSE
- Failed oxygen sensor (front)
- Harness damage in oxygen sensor (front) circuit or loose connector contact
- Failed oxygen sensor (rear)
NOTE: When the oxygen sensor (front) begins to deteriorate, the oxygen sensor output voltage
will deviate from the voltage when the sensor was new (normally 0.5 volt at stoichiometric ratio).
This deviation will be corrected by the oxygen sensor (rear).If the oxygen sensor (rear) responds
poorly because it has deteriorated, it will improperly correct the oxygen sensor (front). Thus,
even when closed loop control is being effected, the fluctuation of the oxygen sensor (front)
output voltage decreases, without intersecting with 0.5 volt. As a result, there is a possibility
of diagnosis code P0125 becoming registered.
- Failed fuel system
- Failed exhaust system
- Failed engine-A/T-ECU
STEP 2.MUT-II/III data list
- Refer to Data List Reference Table .
- Item 12: Air flow sensor
- Item 21: Engine coolant temperature sensor
- Item 59: Cylinder 1, 4 oxygen sensor (front)
- Item 69: Cylinder 2, 3 oxygen sensor (rear)
- Item 95: Manifold absolute pressure sensor
Q: Are the check results normal?
YES:
Go to Step 3 
.NO: Perform the diagnosis code classified check procedure for the sensor that has shown an abnormal data valve (Refer to Inspection Chart for Diagnosis Code
).)
)
Q: Is the check result normal?
YES:
Go to Step 8 .NO: Repair.
- Check output line for damage.
Q: Is the check result normal?
YES:
Go to Step 10 .NO: Repair.
)
Q: Is the check result normal?
YES:
Go to Step 11 .NO: Repair.
- Check output line for damage.
Q: Is the check result normal?
YES:
Go to Step 13 .NO: Repair.
)
- B-01 (No.1 injector connector)
- B-02 (No.2 injector connector)
- B-04 (No.3 injector connector)
- B-05 (No.4 injector connector)
Q: Is the check result normal?
YES:
Go to Step 14 .NO: Repair.
)
)
Q: Is the check result normal?
YES:
Go to Step 16 .NO: Repair.
- Check harness between B-17X (terminal No. 1) engine control relay connector and B-01 (terminal No. 1) No. 1 injector connector.
- Check harness between B-17X (terminal No. 1) engine control relay connector and B-02 (terminal No. 1) No. 2 injector connector.
- Check harness between B-17X (terminal No. 1) engine control relay connector and B-04 (terminal No. 1) No. 3 injector connector.
- Check harness between B-17X (terminal No. 1) engine control relay connector and B-05 (terminal No. 1) No. 4 injector connector.
- Check power supply line for damage.
Q: Are the check results normal?
YES:
Go to Step 17 .NO: Repair.
- Check harness between B-01 (terminal No. 2) No. 1 injector connector and C-134 (terminal No. 1) engine-A/T-ECU connector.
- Check harness between B-02 (terminal No. 2) No. 2 injector connector and C-134 (terminal No. 5) engine-A/T-ECU connector.
- Check harness between B-04 (terminal No. 2) No. 3 injector connector and C-134 (terminal No. 14) engine-A/T-ECU connector.
- Check harness between B-05 (terminal No. 2) No. 4 injector connector and C-134 (terminal No. 21) engine-A/T-ECU connector.
Q: Are the check results normal?
YES:
Go to Step 18 .NO: Repair.