When the ignition switch is placed in the START position, a discrete signal is supplied to the body control module (BCM) notifying it that the ignition is in the START position. The BCM then sends a serial data message to the engine control module (ECM) that crank has been requested. The ECM monitors the park/neutral position switch, or the clutch pedal position sensor. If the transmission is in Park or Neutral, or the clutch is pressed, and there are no DTCs that inhibit engine starting, then the ECM supplies voltage to the control circuit of the CRNK relay. When this occurs, battery voltage is supplied through the CRNK relay to terminal A X1 of the starter solenoid. The starter solenoid energizes, and supplies battery voltage to the starter from the ring terminal X2 to crank the engine.

Schematic Reference

Starting and Charging Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Starting System Description and Operation

Electrical Information Reference

Attempt to start the engine. Verify that the starter solenoid clicks and the engine cranks.

1. Measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 volts.

⇒	If not within the specified range, refer to Charging System Test .

2. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the starter motor case and the negative terminal of the battery.

⇒	If greater than the specified range, test the battery negative cable for an open/high resistance.

3. Verify that a test lamp illuminates between the starter solenoid B+ circuit ring terminal X2 and ground.

⇒	If the test lamp does not illuminate, test the battery positive cable for an open/high resistance.

4. Remove the drive belt. Refer to Drive Belt Replacement .
5. Rotate each pulley by hand. Verify that none of the engine accessories or idler pulleys are seized.

⇒	If any components are seized, replace the appropriate component.

6. Attempt to rotate the crankshaft using a breaker bar, flywheel turner, or other suitable tool. Verify that the engine is not seized.

⇒	If the engine is seized, refer to Engine Will Not Crank - Crankshaft Will Not Rotate .

7. If all circuits test normal, test or replace the starter motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.