The engine controls ignition relay or main relay, is controlled by the engine control module (ECM) depending upon input from the ignition switch. Battery positive voltage is supplied to the relay coil and switch. When the ignition switch is turned to the ON position, the ECM will provide ground on the control circuit of the relay using a low side driver. This will allow voltage through the relay switch contacts to the components. The ECM monitors the voltage level on the control circuit of the relay.

The ECM detects the engine controls ignition relay control circuit is open, shorted to ground, or shorted to voltage.

DTCs P0689 and P0690 are Type A DTCs.

DTCs P0689 and P0690 are Type A DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

1. Ignition ON, command the engine controls (EC) ignition relay OFF with a scan tool. You should hear and feel an audible click for 3-5 seconds.
2. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

1. Ignition OFF, disconnect the EC ignition relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit and ground.

⇒	If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.

3. Verify that a test lamp illuminates between the coil voltage supply circuit and ground.

⇒	If the test lamp does not illuminate, test the coil voltage supply circuit for a short to ground or an open/high resistance.

Important: The ignition 1 voltage circuit is between the EC ignition relay and the ECM. The ignition 1 voltage is a feedback circuit.

4. Connect a 15A fused jumper wire between the switch voltage supply circuit and the ignition 1 voltage circuit.
5. Attempt to start the engine. The engine should start.

⇒	If the engine does not start, test the ignition 1 voltage circuit between the EC ignition relay and the ECM for a short to ground or for an open/high resistance. If the circuit tests normal, replace the ECM.

6. Connect a test lamp between the coil control circuit and the coil voltage supply circuit.
7. Command the EC ignition relay ON with a scan tool. The test lamp should turn OFF for about 3-5 seconds and then turn ON.

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

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

8. Verify that a test lamp illuminates between the switch voltage supply circuit and ground.

⇒	If the test lamp does not illuminate, test the switch voltage supply circuit for a short to ground or an open/high resistance.

9. If all circuits test normal, test or replace the EC ignition relay.

1. Measure for 70-110 ohms of resistance between terminals 85 and 86.

⇒	If the resistance is not within the specified range, replace the relay.

2. Measure for infinite resistance between the following terminals :

•

30 and 86

•

30 and 87

•

30 and 85

•

85 and 87

⇒	If continuity is detected, replace the relay.

3. Install a 20-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Measure for less than 2 ohms between terminals 30 and 87 of the relay.

⇒	If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.