An open fault in any engine control module (ECM) relay circuit will cause a no crank, no start condition and no communication with the scan tool.

The ignition relay is normally an open relay. The relay armature is held in the open position by spring tension. When the ignition switch is turned to the Run or Start position, current will flow through the relay coil. A wire connected to the other end of the relay coil completes the path to ground through the ECM. The electromagnetic field created by the relay coil overcomes the spring tension and moves the armature, allowing the contacts to close.

When the ignition switch is turned to the OFF position, the electromagnetic field collapses. This action allows the spring tension to move the armature away from the relay contacts, which interrupts current flow to the fuses.

If the ECM relay fails to close, the engine will not crank. Communication will not be available with the use of a scan tool.

The ECM relay table assumes that the vehicle battery is fully charged. Refer to Battery Inspection/Test.

DTC P2510 is a type A DTC.

DTC P2510 is a type A DTC.

Schematic References

Connector End View Reference

Component Connector End Views

Electrical Information Reference

Special Tools

J 43244 Relay Puller Pliers

1. If any DTCs other than DTC P2510 are set, diagnose those DTCs first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

Important:  If you cannot duplicate the condition, operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle with the conditions that you observed from the Freeze Frame/Failure Records.

2. The engine starts and runs.
3. DTC 2510 is not set.
4. Engine running, observe the DTC information with a scan tool. DTC P2510 should not set.
5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. With the ignition ON, disconnect the ECM relay and observe with the scan tool for loss of communication.

⇒	If the scan tool can still communicate with the vehicle, test the IGN 1 voltage circuit supplied by the ECM relay for a short to voltage. If the circuits test normal, replace the ECM.

2. With the ignition OFF, probe the relay control circuit at the underhood electrical center with a test lamp connected to battery voltage.

⇒	If the test lamp illuminates test the relay control circuit for a short to ground. If the circuits test normal, replace the ECM.

3. With the ignition ON, probe the relay control circuit at the underhood electrical center with a test lamp connected to a good ground.

⇒	If the test lamp illuminates, repair the short to voltage.

⇒	If the test lamp does not illuminate, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.