When the ignition mode switch is placed in the START position, a discrete signal is supplied to the instrument panel module (IPM) notifying it that the ignition is in the START position. The IPM 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, the ECM then supplies a ground to the control circuit of the starter relay. When this occurs, battery voltage is supplied through the switch of the starter relay to the starter solenoid.

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

DTC P0616 is a C type DTC.

DTC P0616 is a C type 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

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

1. Ignition OFF, disconnect the starter relay.
2. Ignition ON, test for B+ between the starter relay coil supply voltage circuit terminal 85 and ground.

⇒	If less than the specified value, test the supply voltage circuit for a short to ground or an open/high resistance.

3. Ignition ON, connect a test lamp between the starter relay coil supply voltage terminal 85 and the starter relay control circuit terminal 86.
4. With the transmission range selector in park or neutral, cycle the ignition between the OFF and CRANK position. The test lamp should turn ON and OFF when changing between the commanded states.

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

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

5. If the circuits test normal replace the starter relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.