Code 23 Or 53: Knock Sensor
NOTE:
Repair any engine knocking sounds before performing test.
- Turn ignition off. Remove fuse No. 15 (ACG) from underdash fuse 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. Check for continuity between test terminal D3 (right sensor) or D4 (left sensor) and body ground. If continuity is not present, go to step 4). If continuity is present for left sensor, repair short in Red/Blue wire between ECU connector terminal D4 and knock sensor. See Fig 1 . If continuity is present for right sensor, repair short in White wire between ECU connector terminal D3 and knock sensor.
- For left sensor, check continuity between test terminal D4 and Red/Blue wire terminal at knock sensor connector. For right sensor, check continuity between test terminal D3 and White wire terminal at knock sensor connector. If continuity is not present, repair open in wire between ECU terminal D3 or D4 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 ECU.