P1148
DTC P1148 CLOSED LOOP CONTROLOn Board Diagnosis Logic
A/T MODELS ULEV AND M/T MODELS
A/T MODELS EXCEPT ULEV
DTC P1148 is displayed with another DTC for air fuel ratio (A/F) sensor 1. Perform the trouble diagnosis for the corresponding DTC.
DTC Confirmation Procedure (A/T MODELS ULEV AND M/T MODELS)
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)" voltage should go above 0.70 V at least once.
- "HO2S1 (B1)" voltage should go below 0.21 V at least once.
If the check result is NG, perform "Diagnostic Procedure (A/T MODELS ULEV AND M/T MODELS)".
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, P0134 may be displayed on CONSULT-II screen.
6. If DTC is detected, go to "Diagnostic Procedure (A/T MODELS ULEV AND M/T MODELS)".
Overall Function Check (A/T MODELS ULEV AND M/T MODELS)
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 35 [HO2S1 (B1) signal] and 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 (A/T MODELS ULEV AND M/T MODELS)".
Diagnostic Procedure (A/T MODELS ULEV AND M/T MODELS)
Perform trouble diagnosis for DTC P0133. P0133