Code No. P0052: Left Bank Oxygen Sensor (front) Heater Circuit High Input
OPERATION
Power is supplied to the heater power terminal of the left bank oxygen sensor (front) connector from the engine control relay.
The heater of the left bank oxygen sensor (front) connector is controlled by the power transistor in the engine-ECU connector terminal OHFL.
FUNCTION
The power supply to the left bank oxygen sensor (front) heater is controlled by the ON/OFF control of the power transistor in the engine-ECU.
Heating the left bank oxygen sensor (front) heater enables the left bank oxygen sensor (front) to provide good response even when the exhaust emission temperature is low.
TROUBLE JUDGEMENT
Check Conditions
More than 2 seconds have passed since the engine starting sequence was completed.
While the left bank oxygen sensor (front) heater is on.
Battery positive voltage is more than 11 V and is less than 16.5 V.
Judgement Criterion
The left bank oxygen sensor (front) heater current is more than 10.5 A for 2 seconds.
FAIL-SAFE AND BACKUP FUNCTION
None
PROBABLE CAUSES
Failed left bank oxygen sensor (front) heater
Failed engine-ECU
DIAGNOSIS PROCEDURE
STEP 1. Check left bank oxygen sensor (front) itself.
Left bank oxygen sensor (front) check (Refer to ).
Q.
Is the check result normal?
Go to Step 2.
Replace the left bank oxygen sensor (front).
STEP 2. M.U.T.-III diagnosis code
Reconfirmation of diagnosis code.
Q.
Is diagnosis code stored?
Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).