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 clutch pedal is fully depressed or the automatic transmission is in Park/Neutral. If it is, the ECM then supplies 12 volts to the control circuit of the crank relay. When this occurs, battery voltage is supplied through the switch of the crank relay to the starter solenoid.

The ECM detects improper voltage on the control circuit of the crank relay.

DTC P0616 is a C type DTC.

DTC P0616 is a C type DTC.

On manual transmission vehicles, with the clutch fully depressed, the clutch pedal position sensor signals the ECM that conditions are acceptable for cranking. On automatic transmission vehicles, with the vehicle in Park/Neutral, the Park/Neutral Signal circuit is low. This indicates to the ECM that conditions are acceptable for cranking.

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

Ignition ON, verify that no theft deterrent, clutch pedal position or automatic transmission DTCs are set that would cause the ECM not to enable engine starting.

1. Ignition OFF, disconnect the crank relay.
2. Ignition OFF, test for less than 5.0 ohms between the relay ground circuit terminal 85 and ground.

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

3. Ignition OFF, connect a test lamp between the control circuit terminal 86 and the relay ground circuit terminal 85.
4. Fully depress the clutch pedal on manual transmissions or shift lever in PARK on automatic transmissions.
5. Place the ignition to the start position.
6. The test lamp should only illuminate when the ignition is held in the start position.

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

7. If the circuit tests normal, replace the crank relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.