The circuit opening relay provides ignition positive voltage to the fuel pump. The circuit opening relay is controlled by the powertrain control module (PCM) and receives ignition positive voltage from the EFI relay. The PCM monitors the crank signal circuit for voltage when the ignition switch is in the START (engine cranking) position. When the crank signal circuit indicates the engine is cranking the PCM energizes the circuit opening relay. The PCM also energizes the circuit opening relay whenever starter switch indicates cranking. If the crankshaft position (CKP) signal circuit does NOT indicate cranking, the PCM energizes the circuit opening relay based on starter switch input.

Use the following relay cavity table in order to locate the correct cavities to probe during diagnosis. The table layout corresponds to the cavity layout of the relay block.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

Description and Operation

Fuel System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, remove the circuit opening relay.
2. Ignition ON, verify that a test lamp illuminates between the relay coil ignition circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, test the coil ignition circuit for an open/high resistance.

3. Verify that a test lamp illuminates between the relay switch B+ circuit terminal 5 and ground.

⇒

If the test lamp does not illuminate, test the relay switch ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the EFI fuse is open, test the relay controlled output circuit terminal 3 for a short to ground. If the circuit tests normal, test or replace the relay.

4. Connect a 30A fused jumper between the relay switch B+ circuit terminal 5 and the relay controlled output circuit terminal 3. Verify the fuel pump turns ON.

⇒	If the pump is OFF, test the relay controlled output circuit for an open/high resistance. If the circuit tests normal, test the fuel pump ground circuit for an open/high resistance. If the circuit tests normal, replace the fuel pump.

5. Ignition ON, verify that a test lamp does not illuminate between the relay coil control circuit terminal 2 and ground.

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

6. Command the fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp does not illuminate, test the relay coil control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM.

7. If all circuits test normal, test or replace the circuit opening relay.

1. Ignition OFF, disconnect the circuit opening relay.
2. Test for 85-120 ohms at 20°C (68°F) between terminals 1 and 2.

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

3. Test for infinite resistance between the following terminals:

•

5 and 1

•

5 and 2

•

5 and 3

•

1 and 3

⇒	If not the specified range, replace the relay.

4. Install a 20A fused jumper wire between relay terminal 1 and 12 volts. Install a jumper wire between relay terminal 2 and ground. Test for less than 2 ohms between terminals 5 and 3.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.