DTC 23: Knock Sensor Circuit Malfunction Reset the ECM/PCM (see page 11-468). Turn the ignition switch ON (II). Is the MIL on and does it indicated DTC 23? YES - Go to step 5. NO - Go to step 3. Start the engine at 3,000 rpm (min-1) with no load (in Park or neutral) until the radiator fan comes on, then let it idle. Hold the engine at 3,000-4,000 rpm (min-1) for at least 60 seconds. Is the MIL on and does it indicated DTC 23? YES - Go to step 11. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the knock sensor and at the ECM/PCM. Turn the ignition switch OFF. Disconnect ECM/PCM connector A (31P). Check for continuity between ECM/PCM connector terminals A8 and A20. ECM/PCM CONNECTOR A (31P) Wire side of female terminals Is there continuity? YES - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/PCM. NO - Go to step 8.

Disconnect the knock sensor 3P connector. Connect the knock sensor 3P connector terminals No. 2 and No. 3 with a jumper wire. KNOCK SENSOR 3P CONNECTOR Wire side of female terminals Check for continuity between ECM/PCM connector terminals A8 and A20. ECM/PCM CONNECTOR A (31P) Wire side of female terminals Is there continuity? YES - Replace the knock sensor. NO - Repair open in the wire between the ECM/PCM (A8, A20) and the knock sensor.