Code No. P0154: Left Bank Oxygen Sensor (Front) Circuit No Activity Detected

OPERATION

Refer to Code No. P0151: Left bank oxygen sensor (front) circuit low voltage .
Refer to Code No. P0202: No. 2 injector system .
Refer to Code No. P0204: No. 4 injector system .
Refer to Code No. P0206: No. 6 injector system .

FUNCTION

The engine-ECU effects air/fuel ratio feedback control in accordance with the signals from the left bank oxygen sensor (front).
If the left bank oxygen sensor (front) has deteriorated, corrections will be made by the left bank oxygen sensor (rear).
Code No. P0154 becomes stored in memory if a failure is detected in the above air/fuel ratio feedback control system.

TROUBLE JUDGMENT

Check Conditions

20 seconds or more have passed since the engine starting sequence was completed.
Engine coolant temperature is higher than 7°C.
Engine speed is higher than 1,200 r/min.
Volumetric efficiency is higher than 30 %.
Throttle position sensor output voltage is lower than 4 V.
Except while fuel is being shut off.
Monitoring time: 30 seconds.

Judgment Criterion

Left bank oxygen sensor (front) output voltage does not get across lean/rich criteria (about 0.5 V) within about 30 seconds.

PROBABLE CAUSES

Failed left bank oxygen sensor (front)
Harness damage in left bank oxygen sensor (front) circuit
Failed left bank injector
Harness damage in left bank injector circuit
Exhaust leak
Air drawn in from gaps in gasket, seals, etc.
Incorrect fuel pressure
Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

Refer to Data List Reference Table .

Item AE: Left bank oxygen sensor (front)

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 ).

	Go to Step 2 .

STEP 2. Check for exhaust leaks.

Q. Is the check result normal?

	Go to Step 3 .

	Repair.

STEP 3. Check for intake system vacuum leak.

Q. Is the check result normal?

	Go to Step 4 .

	Repair.

STEP 4. Connector check: B-40 left bank oxygen sensor (front) connector

Q. Is the check result normal?

	Go to Step 5 .

	Repair or replace the connector.

STEP 5. Check left bank oxygen sensor (front) itself.

Check left bank oxygen sensor (front) itself (Refer to ).

Q. Is the check result normal?

	Go to Step 6 .

	Replace the left bank oxygen sensor (front).

STEP 6. Connector check: Injector connector

B-104 (No. 2 injector connector).
B-106 (No. 4 injector connector).
B-133 (No. 6 injector connector).

Q. Are the check results normal?

	Go to Step 7 .

	Repair or replace the connector.

STEP 7. Check No. 2, No. 4 and No. 6 injector itself.

Check No. 2, No. 4 and No. 6 injector itself (Refer to

)

Q. Are the check results normal?

	Go to Step 8 .

	Replace the injector.

STEP 8. Connector check: B-29 engine-ECU connector

Q. Is the check result normal?

	Go to Step 9 .

	Repair or replace the connector.

STEP 9. Check harness between B-40 (terminal No. 4) left bank oxygen sensor (front) connector and B-29 (terminal No. 38) engine-ECU connector.

Check output line for damage.

Q. Is the check result normal?

	Go to Step 10 .

	Repair the damaged harness wire.

STEP 10. Check harness between No. 2, No. 4 and No. 6 injector connector and engine-ECU connector.

Check and repair harness between B-104 (terminal No. 2) No. 2 injector connector and B-29 (terminal No. 3) engine-ECU connector.
Check and repair harness between B-106 (terminal No. 2) No. 4 injector connector and B-29 (terminal No. 19) engine-ECU connector.
Check and repair harness between B-133 (terminal No. 2) No. 6 injector connector and B-29 (terminal No. 51) engine-ECU connector.

Check output line for damage.

Q. Are the check results normal?

	Go to Step 11 .

	Repair the damaged harness wire.

STEP 11. Fuel pressure measurement.

Fuel pressure measurement (Refer to Fuel Pressure Test ).

Q. Is the check result normal?

	Replace the engine-ECU.

	Repair.