DTC 66

1. Disconnect knocking sensor electrical connector.
2. Measure resistance across terminals of sensor. Resistance should be 650-800 ohms.
3. If resistance is not as specified, replace knocking sensor.

Fig. 54 Knocking sensor circuit identification.:

Fig. 55 Knocking sensor circuit resistance value chart.:

4. Check resistance of knock sensor circuit as shown in Fig. 54, then compare with specifications in chart, Fig. 55. Terminals No. 28 and No. 37 on 1985-87 Impulse have been changed to terminals No. 29 and No.41 on 1988 Impulse models.
5. If measured resistance is not as specified in chart, repair or replace faulty wires.