P0327

DTC P0327 Knock Sensor (KS) Circuit Grounded:

Knock Sensor (KS) Circuit Grounded:

Circuit Description
The Knock Sensor (KS) circuit consists of two knock sensors connected in parallel and a single wire to the VCM. Each knock sensor has a resistance value of about 8600 ohms. The VCM supplies a 5 volt reference to the sensors where because of the sensor resistance, it is cut in half to about 2.5 volts. When a knock occurs, a small AC voltage is generated by the knock sensors riding on top of the existing 2.5 volts. An AC voltage monitor in the VCM will detect this AC voltage and provide a signal to begin retarding spark until the knock diminishes.

DTC P0327 Will Set When
DTC P0327 will set when knock sensor circuit voltage is less than .64 volt for a period greater than 16 seconds.

Action Taken (VCM will default to)
No action taken.

DTC P0327 Will Clear When
Conditions for fault are no longer present and Tech 1 clear DTCs function is used or 50 ignition switch keycycles have passed with no further faults or ignition switch is turned "OFF" and Fuse #9 (ECM B) fuse is removed for 10 seconds.

DTC Chart Test Description
Number(s) below refer to circled number(s) on the diagnostic chart.

1. The VCM applies 5 volts on CKT 496 which should be present at the knock sensor connectors when the sensors are disconnected.

2. By verifying that knock sensor resistance is within specifications, it can be determined that the problem lies with the connector, sensor installation or VCM.

3. This step calls out the the knock sensor to be faulty.

Diagnostic Aids
Check CKT 496 for a potential ground.

Check knock sensor connections for proper fit. A connector that is fatigued may not fit correctly as the underhood temperature increases.

Also, check for proper installation of PROM (MEM-CAL). Refer to "Intermittents". - Intermittent Malfunctions