Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

The powertrain control module (PCM) controls engine cranking based on a power mode input and the status of the park/neutral position (PNP) or clutch switch. With the transmission in Park or Neutral, or with the clutch pedal pressed, voltage at the PCM PNP/clutch switch signal circuit is high. This indicates to the PCM that conditions are acceptable for cranking. The PNP/clutch start switch signal circuit also supplies voltage to the START relay. When a crank request power mode is seen, the PCM applies ground to the starter relay coil control circuit. This energizes the coil side of the relay, which pulls the switch side of the relay closed, applying voltage to the starter solenoid terminal and engaging the starter solenoid.

Schematic Reference

Connector End View Reference

Engine Electrical Connector End Views

Description and Operation

Starting System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Turn the ignition switch to the start position. The starter solenoid should engage and the engine should crank.

1. Verify that no starter relay, immobilizer, or automatic transmission DTCs are set that would cause the PCM to disable starting.

⇒	If the specified DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

2. Ignition ON, observe the scan tool PCM Ignition 1 Signal parameter with a scan tool. The reading should be greater than 10.0 Volts.

⇒	If less than the specified value, test the ETC, PCM 1, and PCM B fuses, the RUN/CRNK relay, and the PCM ignition voltage circuits for an open/high resistance. If the circuits test normal, replace the PCM.

3. Ignition OFF, remove the START relay.
4. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground.

⇒	If the test lamp does not illuminate, test the START fuse and the B+ circuit for an open/high resistance.

5. Ignition ON, transmission in Park or clutch pedal pressed, verify that a test lamp illuminates between the PNP/clutch start switch signal circuit terminal 86 and ground.

⇒	If the test lamp does not illuminate, test the IGN fuse, RUN/CRANK relay, PNP/clutch switch ignition voltage circuit, and the signal circuit for a short to ground or an open/high resistance. If the circuits test normal, test or replace the PNP switch or the clutch start switch.

6. Connect a test lamp between the park/neutral signal circuit terminal 86 and the relay coil control circuit terminal 85.
7. Ignition ON, transmission in Park, or clutch pedal pressed, turn the ignition switch between the START and RUN positions. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the relay control circuit for a short to ground. If the circuit tests normal, replace the PCM.

⇒	If the test lamp is always OFF, test the relay control circuit for a short to voltage or an open/high resistance. Test the PNP/clutch start switch signal circuit for an open/high resistance. If the circuits test normal, replace the PCM.

8. Install the START relay.
9. Connect a test lamp between the starter solenoid terminal and ground.

Important: The engine may begin to crank.

10. Ignition ON, transmission in Park, command the Starter Relay ON with a scan tool, or turn the ignition switch to the START position. The test lamp should illuminate.

⇒	If the test lamp does not illuminate, test the relay controlled output circuit for an open/high resistance. If the circuit tests normal, test or replace the START relay.

11. If all circuits test normal, test or replace the starter.

PNP Switch

1. Inspect the range selector lever cable for proper adjustment. Refer to Range Selector Lever Cable Adjustment .
2. Inspect the park/neutral position switch for proper adjustment. Refer to Park/Neutral Position and Backup Lamp Switch Adjustment .
3. Ignition OFF. Disconnect the harness connector from the park/neutral switch. Refer to Park/Neutral Position and Backup Lamp Switch Replacement .
4. With the PNP switch in the following positions, test for infinite resistance between the ignition terminal 12 and the signal terminal 1.

•

R

•

OD

•

D

•

2

•

1

⇒	If not the specified value, replace the PNP switch.

5. With the PNP switch in the following positions, test for less than 2 ohms between the ignition terminal 12 and the signal terminal 1.

•

P

•

N

⇒	If greater than the specified range, replace the PNP switch.

START Relay

1. Ignition OFF, remove the START relay. Refer to Relay Replacement .
2. Test for 60-180 ohms between terminals 85 and 86.

⇒	If not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If not the specified value, replace the relay.

4. Install a 20A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2.0 ohms between terminals 30 and 87.

⇒	If greater than specified range, replace the relay.