P0325-KNOCK SENSOR 1 CIRCUIT
For a complete wiring diagram Refer to Section 8W
- 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
| Possible Causes |
| INTERMITTENT DTC |
| (K42) KS SIGNAL CIRCUIT SHORTED TO VOLTAGE |
| (K42) KS SIGNAL CIRCUIT SHORTED TO GROUND |
| (K42) KS SIGNAL CIRCUIT SHORTED TO (K942) KS RETURN |
| (K42) KS SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE |
| (K942) KS RETURN CIRCUIT OPEN OR HIGH RESISTANCE |
| KNOCK SENSOR |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - STANDARD PROCEDUR)
Diagnostic Test
1. DTC IS ACTIVEStart 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 status Active for this DTC?
Yes
- Go to 2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. (K42) KS SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the Knock Sensor connector.
Disconnect the 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 Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDUR).
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 (K42) KS Signal circuit for a short to ground.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDUR).
4. (K42) KS SIGNAL CIRCUIT SHORTED TO (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 Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDUR).
5. (K42) KS SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
Measure the resistance of the (K42) KS Signal circuit between the Knock Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
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 Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDUR).
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 Powertrain Control Module (PCM) harness connector.
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 Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDUR).
7. KNOCK SENSOR
Turn the ignition off.
Connect the Powertrain Control Module (PCM) connector.
Replace the Knock Sensor in accordance with the Service Information.
Start the engine and allow it to reach normal operating temperature.
With the scan tool, select View DTCs.
Is status Active for this DTC?
Yes
- Go to 8
No
- Test Complete.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDUR).
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.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDUR).
No
- Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
- Perform the PCM Verification Test Ver. 1 (Refer to 9 - ENGINE - STANDARD PROCEDUR).