222 Knock Control Test Pulse - Signal Implausible

P1386

222 Knock Control Test Pulse - 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 4 760 rpm

P1385 and P1386
- Engine running

P1384 - P1386:

NOTE: When a fault is stored, the ignition angle is retarded for all cylinders in the range in which knock control is active.


Wiring Diagram







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.