Knock Sensor: Testing and Inspection

Knock Sensor Schematic:

A faulty knock sensor will set code 22 in the on-board diagnostic system. Refer to the schematic diagram and test the sensor with the diagnostic chart.

Wire color code identification:

L: Blue
B: Black
Y: Yellow
G: Green
R: Red
W: White
Br: Brown
Lg: Light green
Gr: Gray

Knock Sensor Diagnostic Chart:

KNOCK SENSOR DIAGNOSTIC CHART

Knock Sensor Testing:

CHECK ECU VOLTAGE

With ignition "ON," measure voltage between ECU connector terminal (B56)5 and ground. It should read 3-4V.

CHECK KNOCK SENSOR

With knock sensor disconnected, measure resistance between sensor terminals and ground. It should read approximately 560K Ohms.

CHECK HARNESS BETWEEN ECU AND KNOCK SENSOR

1. Disconnect ECU and knock sensor connectors.
2. Measure resistance between ECU and knock sensor connectors and ground as follows:

Connector & terminal: Resistance:
(B56)5-(B19)1 0 Ohms
(B19)1-Ground 1M Ohms min.