Trouble code definition: slow response of the rear oxygen sensor to the decrease in oxygen concentration.
Conditions of fault code appearance: The voltage signal transition time of the rear oxygen sensor from the high concentration state to the low concentration state exceeds the set threshold.
Possible causes of malfunction:
- The rear oxygen sensor has failed due to aging.
Elimination methods:
| Steps | Control | Yes | No |
|---|---|---|---|
| 1 | Turn the ignition switch to ON | Go to step 2 | — |
| 2 | Using the diagnostic instrument, determine whether the ECM has a corresponding fault code, and save the frame information with the data of the time of the fault occurrence | Go to step 3 | Checking other fault codes |
| 3 | Replace the rear oxygen sensor and connect the wiring harness correctly. Start the car and drive until the coolant temperature is normal. Drive several times at a speed of about 70 km/h, releasing the accelerator pedal to let the car roll - does the malfunction occur again? | Help with diagnostics | The system is working normally |