GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2009 🢒 Vibe - AWD 🢒 Engine 🢒 Engine Controls and Fuel - 1.8L (LAY) 🢒 Ignition Relay Diagnosis

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The EFI relay and the ignition 2 relay provides ignition positive voltage to the control module and other engine control components anytime the ignition is ON. One side of the coil of the relay is always grounded. When voltage is applied to the other side of the coil, the relay coil is energized creating a magnetic field that closes the switch side of the relay. The switch side of the relay receives power from the applicable fuse protected positive voltage circuit.

Both the EFI relay and the ignition 2 relay are an integral part of the multifunction alarm module located in the fuse block - underhood. The circuit protection fuses for both relays are also a part of the multifunction alarm module.

Diagnostic Aids
    • The relay electrical contacts in the multifunction alarm module may be pitted or sticking. Replace the module, if gently tapping or wiggling the module causes a change in the relay's operation.
    • The performance of the multifunction alarm module may be affected by temperature. Check the module operation after sitting outside overnight and after running the engine for 30 minutes.
    • If the EFI fuse opens during cranking, check for a shorted fuel pump/circuit. The EFI relay supplies current to the circuit opening relay that supplies power to the fuel pump. The circuit opening relay is energized during cranking and when reference pulses are detected by the PCM.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Warning: An electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electric fan.

  1. Ignition OFF, remove the multifunction alarm module.
  2. Ignition OFF, disconnect the X1, X2, and X3 harness connectors at the module.
  3. Ignition OFF, test for 5 ohms or less between relay coil ground circuit terminal listed below and ground G104.
    4. • EFI relay terminal X2-3
    • IG2 relay terminal X3-3
    ⇒If greater than the specified range, repair the open/high resistance in the relay coil ground circuit.
  4. Ignition OFF, verify that a test lamp does not illuminate between the relay coil control high circuit terminal listed below and ground.
    5. • EFI relay terminal X2-2
    • IG2 relay terminal X3-2
    ⇒If the test lamp illuminates, test the coil control circuit for a short to voltage. If the EFI relay coil control high circuit tests normal, replace the PCM.

    Note: Perform this test for the IG2 relay only.

  5. Ignition ON, verify that a test lamp illuminates between the IG2 relay coil control high circuit terminal X3-2 and ground.
    6. ⇒If the test lamp does not illuminate, test the coil control circuit for a short to ground or an open/high resistance.

    Note: Perform this test for the EFI relay only.

  6. Ignition OFF, connect the X1 and X3 harness connectors to the multifunction alarm module.
  7. Ignition ON, verify that a test lamp illuminates between the EFI relay coil control high circuit terminal X2-2 and ground.
    8. ⇒If the test lamp does not illuminate, test the coil control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM.
  8. Verify a test lamp illuminates between the relay switch B+ circuit terminal X1-1 and ground.
    9. ⇒If the test lamp does not illuminate, test the relay switch B+ circuit for a short to ground or an open/high resistance.
  9. Ignition OFF, install the multifunction alarm module.
  10. Ignition ON, verify the test lamp illuminates between the applicable relay fuse and ground.
    11. ⇒If the test lamp does not illuminate, replace the multifunction alarm module.
    ⇒If the test lamp illuminates and the fuse is open, test the relay controlled output circuit terminal listed below for a short to ground.
    • EFI relay terminal X2-4
    • IG2 relay terminal X3-4
    ⇒If the circuit tests normal, replace the multifunction alarm module.
  11. Connect a 20A fused jumper between the B+ and the relay controlled output circuit terminal listed below. Verify the relay controlled component of concern activates.
    12. • EFI relay terminal X2-4
    • IGN2 relay terminal X3-4
    ⇒If the component does not activate, test the relay controlled output circuit for an open/high resistance. If the circuit tests normal, test the component ground circuit for an open/high resistance. If the circuit tests normal, replace the component as necessary.
  12. If all circuits test normal, replace the multifunction alarm module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control module replacement, setup, and programming