Code 23 Or 53: Knock Sensor
NOTE:
Repair any engine knocking sounds before performing test.
- Turn ignition off. Remove BACK UP fuse from underhood fuse/relay box for 10 seconds to reset ECU. Warm engine until cooling fan comes on. With transmission in Neutral, hold engine speed at 3000-4000 RPM for 10 seconds. Check ECU for fault codes. See RETRIEVING CODES . If Code 23 or 53 is not present, problem is intermittent. Check for poor connections at ECU connector and knock sensor connector.
- Test drive vehicle and retest. If Code 23 or 53 is present, turn ignition off. Connect ECU Test Harness (07LAJ-PT3010A ) between ECU and ECU connector, leaving ECU disconnected. See Figure . Disconnect knock sensor connector 308 located on left shock tower.
- Check for continuity between test terminal C1 (sensor No. 2) or C3 (sensor No. 1) and body ground. If continuity is not present, go to next step. If continuity is present between test terminal C1 and body ground, repair short in Red/Blue wire between ECU connector and knock sensor. See Fig 1 . If continuity is present between test terminal C3 and body ground, repair short in Orange/White wire between ECU connector and knock sensor.
- Disconnect knock sensor connector 308. See Fig 1 . For sensor No. 1, check continuity between test terminal C3 and Red/Blue wire terminal at knock sensor connector knock sensor 308. See Fig 1 . For sensor No. 2, check continuity between test terminal C1 and Orange/White wire terminal at knock sensor connector 308. If continuity is not present, repair open in wire between ECU connector and knock sensor.
- If continuity is present, replace ECU with a known good unit. Warm engine until cooling fan comes on. With transmission in Neutral, hold engine speed at 3000-4000 RPM for 10 seconds. Check ECU for fault codes. If Code 23 or 53 is present, replace knock sensor. If Code 23 or 53 is not present, replace original ECU.