P1148

P1148 CLOSED LOOP CONTROL

On Board Diagnosis Logic:

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 above condition at least 50 consecutive seconds.
During this test P0134 and/or P0154 may be displayed on CONSULT-II screen.

6. If DTC is detected go to "Diagnostic Procedure" below.




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 [Heated oxygen sensor 1 bank 1 signal] or 62 [Heated oxygen sensor 1 bank 2 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" below.

Diagnostic Procedure

Step 1 - 4:

Step 5:

Step 6:

Step 7 - 8:

Step 9 - 10:

Step 11:

Step 12 - 14: