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 message to the engine control module (ECM) that crank has been requested. The ECM then verifies that the transmission is in Park or Neutral. If it is, then the ECM then supplies 12 volts to the control circuit of the CRNK relay. When this occurs, battery voltage is supplied through the switch of the crank relay to the starter solenoid terminal A X1. The ECM always supplies some voltage to the control circuit of the CRNK relay, through a pull-up resistor. If the circuit becomes open or shorted, then the ECM will set DTCs.

The ECM detects low voltage on the CRNK relay control circuit.

DTC P0615 is a type C DTC.

DTC P0615 is a type C DTC.

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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Turn the ignition switch between the start and run positions while observing the following control circuit status parameters.

Each parameter should toggle between OK and Not Run or Not Run and OK.

1. Ignition OFF, disconnect the CRNK relay,
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 relay ground circuit terminal 86 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the control circuit terminal 85 and the ground circuit terminal 86. Turn the ignition switch to the start position. The test lamp should turn ON only when the ignition is held in the start position for a maximum of 10 seconds, and then turn OFF.

⇒	If the test lamp is always ON, test the control circuit for short to voltage. If the circuit tests normal, replace the ECM.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

4. If all circuits test normal, test or replace the relay.

CRNK Relay

1. Ignition OFF, disconnect the CRNK relay.
2. Test for 60-180 Ω between terminals 85 and 86 of the relay.

⇒	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 20 amp 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 Ω between terminals 30 and 87 of the relay.

⇒	If greater than specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.