Knock sensor

DTC P0325: KNOCK SENSOR (KS) CIRCUIT MALFUNCTION

DTC Set Criteria
At least 60 seconds have passed since ignition was turned on or engine was started. Engine speed is more than 3000 RPM. Code will set if knock sensor output voltage (peak voltage in each 1/3 turn of crankshaft) has not changed more than 60 millivolts in last consecutive 200 periods.

Probable Causes

†Knock sensor failed.
†Open or short in knock sensor circuit or loose connector.
†Engine Control Module/Powertrain Control Module (ECM/PCM) failed.

Diagnostic Procedure (3.0L)
1. Turn ignition off. Disconnect knock sensor 2-pin connector. Check knock sensor connector for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step 6. If problem does not exist, go to next step.

2. Check for continuity between ground and knock sensor connector terminal No. 2 (Black wire). If continuity exists, go to next step. If continuity does not exist, repair wire between ground and knock sensor connector, then go to step 6.

3. Check ECM connector C-62 or PCM connector C-59 for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step 6. If problem does not exist, go to next step.

4. Check for open or short in White wire between knock sensor connector terminal No. 1 and ECM connector C-62 terminal No. 91 or PCM connector C-59 terminal No. 90. If problem exists, repair White wire, then go to step 6. If problem does not exist, go to next step.

5. Replace knock sensor. Test drive vehicle following OBD-II drive cycle other monitor pattern. See OTHER MONITOR under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0325 is output, replace ECM/PCM, then go to next step. If DTC P0325 is not output, inspection is complete.

6. Start engine and let idle. Using scan tool, check data list item No. 44 (ignition coils and ignition power transistor). Check ignition timing with knock sensor connected and disconnected. Ignition timing should retard more with knock sensor connector disconnected than with knock sensor connector connected. If ignition timing retards, repair is finished. If ignition timing does not retard, retry diagnostic procedure.

Other Monitor
This monitor applies to DTCs not covered by the rest of the monitors. Following conditions must be met during the test:

†Engine coolant temperature must be 176°F (80°C) or more.
†Atmospheric temperature is 41°F (5°C) or more.
†Selector lever is in "D" range.

Monitor takes about 10 minutes to complete. To run monitor, use illustration. See Fig. 8. Perform steps as follows:

1. Remove all test equipment from vehicle and install all components and connectors that were removed or disconnected during testing.

2. After engine is completely warmed up, turn ignition off.

3. Start engine and quickly accelerate to 35-40 MPH.

4. Drive for 5 minutes or more at 35-40 MPH (4th gear on M/T).

5. Return vehicle to shop and let idle. While engine is idling, A/C switch must be in OFF position, lights and accessories must be off, steering wheel must be straight ahead, and automatic transaxle must be in "P" range. After idling for 5 minutes, turn ignition off.