The knock sensor is under the intake manifold. You remove the intake and unscrew the sensor. There is a pinpoint test you can do.
DG1- CHECK KS SENSOR RESISTANCE
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.
Disconnect KS, measure resistance through the KS harness connector pins
Is resistance between 4.39 and 5.35 megaohms?
Yes = GO to DG2
No = For resistance less than 4.39 megohm: GO to DG3
DG2 - CHECK FOR OPEN OF KS CIRCUIT BETWEEN KS HARNESS CONNECTOR AND PCM HARNESS CONNECTOR
Disconnect PCM.
Measure resistance of the KS+ circuit between the PCM harness connector pin and the KS harness connector.
Measure resistance of KS- circuit between the PCM harness connector pin and the KS harness connector.
Is each resistance less than 5.0 ohms?
Yes = REPLACE KS.
No = REPAIR open circuit.
DG3 - CHECK KS CIRCUIT FOR SHORT TO GROUND IN HARNESS
Measure resistance between the KS- circuit at the PCM harness connector and chassis GND.
Measure resistance between the KS+ circuit at the PCM harness connector and chassis GND.
Is each resistance greater than 10,000 ohms?
Yes = GO to DG4
No = SERVICE short circuit.
DG4 - CHECK KS CIRCUITS FOR SHORT TO POWER IN HARNESS
Disconnect PCM.
Turn Key on.
Measure voltage between the KS+ circuit at the PCM harness connector and battery negative post.
Is the voltage less than 0.5 volt?
Yes = REPLACE PCM See: Programming and Relearning
No = SERVICE short circuit.
DG5 - CHECK KS CIRCUIT FOR INTERMITTENT FAULT
Key off.
Measure the resistance for KS+ between the PCM and KS harness connectors, while viewing the ohm meter, grasp the vehicle harness as close to the knock sensor(s) as possible. Shake and bend a small section of the harness from the KS sensor to the PCM.
Measure the resistance for KS- between the PCM and KS harness connectors, while viewing the ohm meter, grasp the vehicle harness as close to the knock sensor(s) as possible. Shake and bend a small section of the harness from the KS sensor to the PCM.
Tap the PCM and KS connectors if possible.
Are the resistance readings changing?
Yes = ISOLATE fault and SERVICE as required.
No = GO to DG6
DG6 - CHECK INTERNAL PCM RESISTANCE
Disconnect knock sensor (KS) harness connector.
Measure resistance between KS+ and KS- pins through the harness connector.
Is resistance greater than 10,000 ohms?
Yes = REPLACE KS. If concern is still present, REPLACE PCM See: Programming and Relearning).
No = REPLACE PCM See: Programming and Relearning.
Images (Click to make bigger)
Monday, December 7th, 2020 AT 4:39 PM
(Merged)