P1168

On Board Diagnosis Logic
* The closed loop control has the one trip detection logic.
Malfunction is detected when the closed loop control function for bank 1 does not operate even when vehicle is driving in the specified condition, the closed loop control function for bank 2 does not operate even when vehicle is driving in the specified condition.

Possible Cause
- The heated oxygen sensor 1 (front) circuit is open or shorted.
- Heated oxygen sensor 1 (front)
- Heated oxygen sensor 1 (front) heater

DTC Confirmation Procedure

CAUTION: Always drive vehicle at a safe speed.

NOTE: If "DTC Confirmation Procedure" has been previously conducted, always turn ignition switch "OFF" and wait at least 10 seconds before conducting the next test.

TESTING CONDITION:
- Never raise engine speed above 3,600 rpm during the "DTC Confirmation Procedure". If the engine speed limit is exceeded, retry the procedure from step 2.
- Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.

WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select "DATA MONITOR" mode with CONSULT-II.




3. Hold engine speed at 2,000 rpm and check one of the following.
- "HO2S1 (B1)/(B2)" voltage should go above 0.70 V at least once.
- "HO2S1 (B1)/(B2)" voltage should go below 0.21 V at least once.
If the check result is NG, perform "Diagnosis Procedure".
If the check result is OK, perform the following step.

4. Let engine idle at least 5 minutes.




5. Maintain the following condition at least 50 consecutive seconds.
During this test, P0130 and/or P0150 may be displayed on CONSULT-II screen.
6. If DTC is detected, go to "Diagnostic Procedure".

Overall Function Check
Use this procedure to check the overall function of the closed loop control. During this check, a DTC might not be confirmed.

WITH GST
1. Start engine and warm it up to normal operating temperature.




2. Set voltmeter probes between ECM terminal 63 [HO2S1 (B1) signal] or 62 [HO2S1 (B2) signal] and engine ground.
3. Check the following with engine speed held at 2,000 rpm constant under no-load.
- The voltage should go above 0.70 V at least once.
- The voltage should go below 0.21 V at least once.

4. If NG, go to "Diagnostic Procedure".

Steps 1 - 4:

Step 5:

Steps 6 - 7:

Steps 8 - 9:

Step 10:

Step 11:

Steps 12 - 14:

Step 15:

Diagnostic Procedure