Knock Sensor: Testing and Inspection

ESC Knock Sensor:

INSPECTION
The "Scan" tool will have two positions to check for diagnosing this circuit. Knock signal is used to monitor the input signal from the knock sensor. This position should display "YES" to indicate knock is being detected.

Knock retard is the indication of how much the Electronic Control Module (ECM) is retarding the spark.

Code 43 is designed to diagnose the knock sensor and wiring, so problems encountered with this circuit should set the code. However, if no Code 43 was set but the Engine Spark Control (ESC) system is suspected because detonation was the customer's complaint, refer to Chart C-5. Testing and Inspection