Inspection of Knock Sensor

Fig. 24 Testing retard function with substitute sensor:

1. Test ``Retard Function'' and, if ignition timing does not retard, proceed to step 2.
2. Disconnect knock sensor connector.
3. Connect known good knock sensor in place of sensor in vehicle and ground it Fig. 24.
4. Tap known good knock sensor and ensure ignition timing retards. If so, replace knock sensor.