Knock Sensor: Testing and Inspection

KNOCK SENSOR (KS)
The knock sensor is a piezoelectric device attached to the cylinder block that senses pressure from engine knock conditions. This vibrational pressure is then converted into a voltage signal which is delivered as output. It engine knock occurs, ignition timing is retarded to suppress it.

Circuit Diagram (Knock Sensor):

Harness Connector:

Troubleshooting Procedures:

TROUBLESHOOTING HINTS
1. The MIL is ON or the DTC is displayed on the HI-SCAN (PRO) under the following condition:
1. When the knock sensor signal is not detected, even though the engine is in an overload condition.
2. When the knock sensor signal is abnormally low.

Harness Inspection Procedures (Knock Sensor):