## PGM-FI System

#### DTC Troubleshooting (cont'd)

11-515

DTC 4: CKP Sensor Circuit Malfunction

1. Reset the ECM/PCM (see page 11-468).
2. Start the engine.

Is the MIL on and does it indicate DTC 4?

YES | - Go to step 3.
NO | - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the CKP sensor and at the ECM/PCM.

3. Turn the ignition switch OFF.
4. Disconnect the CKP sensor 3P connector.
5. Turn the ignition switch ON (II).
6. Measure voltage between the CKP sensor 3P connector terminal No. 3 and body ground.

CKP SENSOR 3P CONNECTOR

Wire side of female terminals

Is there battery voltage?

YES | - Go to step 7.
NO | - Repair open in the wire between the PGM-FI main relay 1 and the CKP sensor.

7. Measure voltage between the CKP sensor 3P connector terminal No. 1 and body ground.

CKP SENSOR 3P CONNECTOR

Wire side of female terminals

Is there about 5 V?

YES | - Go to step 8.
NO | - Go to step 10.

8. Measure voltage between the CKP sensor 3P connector terminals No. 2 and No. 3.

CKP SENSOR 3P CONNECTOR

Wire side of female terminals

Is there battery voltage?

YES | - Go to step 9.
NO | - Repair open in the wire between the CKP sensor and G101.

9. Substitute a known-good CKP sensor and recheck.

Is the MIL on and does it indicate DTC 4?

YES | - Substitute a known-good ECM/PCM and recheck. If symptom/indication goes away, replace the original ECM/PCM.
NO | - Replace the original CKP sensor.