Knock Sensor Control Unit
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1992 Volkswagen Passat, 1992 Volkswagen Jetta, 1992 Volkswagen Golf, 1992 Volkswagen GTI, and 1992 Volkswagen Fox. However, it is still accessible from the selected car via links, so may be relevant.
- Check ignition coil and Hall Effect sender before checking knock sensor control unit. Remove knock sensor control unit harness connector. Turn ignition on. Using a voltmeter, check for battery voltage between terminals No. 3 and No. 5, and terminals No. 3 and No. 6 of knock sensor control unit. See Figure . Open throttle valve. Voltage should drop to zero volt.
- If voltage does not drop to zero volt, check voltage between terminals No. 3 and No. 8 of knock sensor control unit while fully opening throttle valve. If battery voltage is not present when throttle opens fully, replace throttle valve switch.
- Remove Hall Effect sender connector and connect voltmeter to outside terminals. Turn ignition on. There should be 5 volts present. Turn ignition off. Connect voltmeter between terminals No. 1 (-) and No. 15 (+) of ignition coil. Turn ignition on and touch center terminal of Hall Effect sender briefly to ground. Voltage should jump momentarily to approximately 2 volts. If voltage does not jump, replace knock sensor control unit.