Diagnosis Procedure
1 Perform adaptation.
1. Switch on the ignition.
2. Wait one minute.
Do not press the accelerator.
3. Switch off the ignition for at least 10 seconds.
4. Read out the fault memory.
DME 7.8
P1385
221 Knock control offset - signal implausible
Diagnosis conditions
- Engine speed less than 5,600 rpm
- Knock control active
- Engine load greater than 45 %
Possible fault cause
- DME control module
NOTE: When a fault is stored, the ignition angle is retarded for all cylinders in the range in which knock control is active.
Diagnosis/troubleshooting
On Board Diagnostic
P1385
Knock Control Offset - Signal Implausible
Function
The knock control system is designed to detect knocking combustion and to retard the ignition timing for the knocking cylinder(s). When no more
knocking combustion occurs, the ignition timing is advanced again gradually to the specified value. Because of the engine design (opposed-cylinder
engine), two knock sensors are needed.
Diagnosis conditions
P1384
- Speed between 800 and 4760 rpm