dg1: Service Code 25: Generate Knock Manually
| Steps | _Locate knock sensor and prepare to rap/tap on exhaust manifold with a 4 oz. hammer
_Run Engine Running Self-Test (engine must be at operating temperature) _Tap exhaust manifold directly above the knock sensor immediately after the dynamic response code is given |
| Result | Is service Code 25 present? |
| Direction | YES
GO to Continue NO Knock system OK. Rerun Engine Running Self-Test and Service any other codes from that 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 |   "> |