dg6: Test Processor with Substitute Knock Sensor
| Steps | _Key Off, wait 10 seconds
_Connect known good Knock Sensor to the vehicle harness _Do not install this sensor in the engine _Run Engine Running Self-Test. Engine must be at operating temperature _Tap the substitute Knock Sensor with a 4 oz. hammer immediately after the dynamic response code is given. |
| Result | Is service Code 25 present? |
| Direction | YES
Replace processor. Reconnect original Knock Sensor. Rerun Quick Test NO Install new Knock Sensor. Rerun Quick Test |
| Notes | It is not necessary to "goose" the throttle. Ignore all other codes except Code 25 |
| Component | Knock Sensor |
| Description | The
Knock Sensor is a piezoelectric accelerometer with the sensor designed
to resonate at approximately the same frequency as engine knock. The
sensor uses resonant frequency to mechanically amplify the vibrations.
This method allows relatively large signals to be achieved without
electrical amplification and with small package size. The sensor has a
thin circular piezoelectric ceramic disk which is bonded to a metal
diaphragm.
Electrical connections are made through a two pin integral connector. |
| Location | Threaded into lower intake manifold |
| Wire Colors | Yellow with Red stripe
Black with White stripe |
| Notes | M12 x 1.5mm-6g
5.7K Resonant Frequency Grey |
| Image |   "> |