P0326

DIAGNOSTIC TROUBLE CODE PO326
Knock sensor, input to control module faulty.

Fault Symptom.
CHECK ENGINE lamp (MIL) on,
Engine performance may be down.

Condition
The input from the knock sensor is active or absent for more than four seconds at engine speeds above 1800 rpm.

Diagnostic Procedure.
1. Check that the knock sensor connector makes good contact.

2. With the ignition switched OFF, connect a BOB between the MOTRONIC control module and the wiring.
Start the engine and check the knock sensor's signal voltage by taking a reading across 11 and 30 on the BOB.
When the engine is rewed up the voltage should be higher than 20 mV.

If the voltage is OK, proceed to step 4.
If it is not, continue with step 3.

3. Check the screened lead between the knock sensor and pin 11 of the control module for continuity/shorting.





4. Check that the knock sensor is tightened to a torque of 22 Nm (16 ft lb).

5. Then check the knock sensor signal by measuring the voltage directly on the sensor while lightly tapping the knock sensor retaining screw.
The voltage should then go up to at least 100 mV.

If no voltage is obtained (the knock sensor appears to be completely "dead"), change the sensor.

6. Clear all trouble codes and drive the car on the road to check whether any codes are generated afresh.

If they are, continue at "Before Control Module Replacement" for further diagnostic instructions. Before Replacing A Control Module