NGC

P0325-KNOCK SENSOR 1 CIRCUIT





For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
With the engine running, battery voltage greater than 10.4 volts, and no system voltages DTCs present. The low voltage diagnostic runs continuously. The high voltage diagnostic runs during engine closed throttle conditions.

- Set Condition:
The PCM detects that the Knock Sensor input voltage is:

- above 4.0 volts

- less than or equal to 1.0 volt with engine RPM at or above 2200

- equal to 0.0 volts with engine RPM below 2200





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview

Diagnostic Test

1. DTC IS ACTIVE
Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to reset.

With the scan tool, select View DTCs.
Is the DTC Active at this time?

Yes

- Go to 2

No

- Refer to the CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking For An Intermittent DTC

2. (K42) KS SIGNAL CIRCUIT SHORTED TO VOLTAGE




Turn the ignition off.
Disconnect the Knock Sensor connector.
Disconnect the C2 Powertrain Control Module (PCM) connector.
Turn the ignition on.
Measure the voltage of the (K42) KS Signal circuit in the Knock Sensor harness connector.
Is there any voltage present?

Yes

- Repair the (K42) KS Signal circuit for a short to voltage.
- Perform the PCM Verification Test. Powertrain Verification Test

No

- Go to 3

3. (K42) KS SIGNAL CIRCUIT SHORTED TO GROUND




Turn the ignition off.
Measure the resistance between ground and the (K42) KS Signal circuit in the Knock Sensor harness connector.
Is the resistance above 100 ohms?

Yes

- Go to 4

No

- Repair the short to ground in the (K42) KS Signal circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

4. (K42) KS SIGNAL CIRCUIT SHORTED TO THE (K942) KS RETURN CIRCUIT




Measure the resistance between the (K42) KS Signal circuit and the (K942) KS Return circuit in the Knock Sensor harness connector.
Is the resistance above 100 ohms?

Yes

- Go to 5

No

- Repair the (K42) KS Signal circuit for a short to the (K942) KS Return circuit.
- Perform the PCM Verification Test. Powertrain Verification Test

5. (K42) KS SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE




CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (K42) KS Signal circuit between the Knock Sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 6

No

- Repair the (K42) KS Signal circuit for an open circuit or high resistance.
- Perform the PCM Verification Test. Powertrain Verification Test

6. (K942) KS RETURN CIRCUIT OPEN OR HIGH RESISTANCE




Measure the resistance of the (K942) KS Return circuit between the Knock Sensor harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 7

No

- Repair the (K942) KS Return for an open circuit or high resistance.
- Perform the PCM Verification Test. Powertrain Verification Test

7. KNOCK SENSOR
Turn the ignition off.
Replace the Knock Sensor.
Connect the C2 Powertrain Control Module (PCM) connector.
Turn the ignition on.
With the scan tool, clear DTCs.
Start the engine and allow it to reach normal operating temperature.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

NOTE: It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to reset.

With the scan tool, select View DTCs.
Is the DTC Active at this time?

Yes

- Go to 8

No

- Test complete.
- Perform the PCM Verification Test. Powertrain Verification Test

8. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Knock Sensor and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Verify that there is good pin to terminal contact in the Knock Sensor and Powertrain Control Module connectors.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test.Powertrain Verification Test

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test.Powertrain Verification Test