Operation CHARM: Car repair manuals for everyone.

Knock Sensor: Testing and Inspection




1. Connect tool 49H0189A1 or equivalent to green, 6 pin check connector.
2. Ground green, 1 pin test connector with jumper wire.
3. Turn ignition switch to On position.
4. Tap right engine hanger (drive belt side) and ensure monitor lamp on tool flashes.
5. If lamp does not flash, connect a known good knock sensor to vehicle wiring harness and ground it.
6. Repeat step 4. If monitor lamp flashes, replace knock sensor. If monitor lamp does not flash, replace knock control unit.