## PGM-FI System

#### DTC Troubleshooting (cont'd)

11-245

DTC 23: Knock Sensor Circuit Malfunction

1. Reset the ECM/PCM (see page 11-168).
2. 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.

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.
4. 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.

5. Turn the ignition switch OFF.
6. Disconnect ECM/PCM connector A (31P).
7. 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.

8. Disconnect the knock sensor 3P connector.
9. 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

10. 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.