Code No. P0158: Left Bank Oxygen Sensor (Rear) Circuit High Voltage
OPERATION
- The sensor signal is inputted to the engine-A/T-ECU (terminal
No. 116) from the left bank oxygen sensor (rear) output terminal (terminal No. 4).
- The left bank oxygen sensor (rear) (terminal No. 2) is earthed with engine-A/T-ECU
(terminal No. 96).
FUNCTION
- The left bank oxygen sensor (rear) converts the concentration
of oxygen in the exhaust emission into a voltage and inputs the signal to the engine-A/T-ECU.
- When the air-fuel ratio is richer than the theoretical air-fuel ratio, the left
bank oxygen sensor (rear) outputs a voltage of about 1 V. When it is leaner than the theoretical
air-fuel ratio, it outputs a voltage of about 0 V.
- In response to the signal, the engine-A/T-ECU controls the fuel injection amount
so that the air-fuel ratio can be equivalent to the theoretical air-fuel ratio.
TROUBLE JUDGMENT
Check Condition
- 2 seconds later from when the engine starts.
- Left bank oxygen sensor (rear) output voltage is more than 1.2 V for 2 seconds.
PROBABLE CAUSES
- Short circuit in left bank oxygen sensor (rear) circuit
or loose connector contact
- Failed engine-A/T-ECU
DIAGNOSIS PROCEDURE |
STEP 1. M.U.T.-III data list |
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Q.
Is the check result normal?
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Intermittent malfunction (Refer to GROUP 00 -
How to Use Troubleshooting/Inspection
Service Points -
How to Cope with Intermittent Malfunctions ). |
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Go to Step 2 . |
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STEP 2. Connector check: C-02 left bank oxygen sensor (rear) connector |
Q.
Is the check result normal?
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Go to Step 3 . |
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Repair or replace the connector. |
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STEP 3. Connector check: D-217 engine-A/T-ECU connector |
Q.
Is the check result normal?
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Go to Step 4 . |
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Repair or replace the connector. |
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STEP 4. Check harness between C-02 (terminal No. 4) left bank oxygen sensor (rear) connector and D-217 (terminal No. 116) engine-A/T-ECU connector. |
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Q.
Is the check result normal?
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Go to Step 5 . |
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Repair the damaged harness wire. |
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STEP 5. Check harness between C-02 (terminal No. 2) left bank oxygen sensor (rear) connector and D-217 (terminal No. 96) engine-A/T-ECU connector. |
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Q.
Is the check result normal?
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Go to Step 6 . |
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Repair the damaged harness wire. |
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STEP 6. M.U.T.-III data list |
|
Q.
Is the check result normal?
|
Intermittent malfunction (Refer to GROUP 00 -
How to Use Troubleshooting/Inspection
Service Points -
How to Cope with Intermittent Malfunctions ). |
|
Replace the engine-A/T-ECU. |
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