GM Service Manual Online
For 1990-2009 cars only

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.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+

1

1

--

--

Accessory Voltage

1

1

--

--

Control

1

1

2

--

Phase A

1

1

1

--

Neutral

1

1

1

--

Ground

--

1

1

--

1. Accessory AD/DC power control module OFF

2. Accessory AD/DC power control module ON

Circuit/System Description

Battery voltage is supplied to the accessory AC/DC power control module from the 25-amp PWR OUTLET fuse. When the ignition is turned ON, ignition voltage is supplied to the auxiliary power outlet using the accessory voltage circuit. When a 115-volt AC powered device is plugged into the auxiliary power outlet, with the ignition ON, the normally open plug-inserted switch, located internally in the auxiliary power outlet, closes. The accessory AC/DC power control module detects a voltage signal on the control circuit, and the accessory AC/DC power control module enables the 115 V AC to the auxiliary power outlet.

Reference Information

Schematic Reference

Cigar Lighter/Power Outlet Schematics

Connector End View Reference

Power Outlet Connector End Views

Description and Operation

Power Outlets Description and Operation

Electrical Information Reference

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

Circuit/System Verification

Ignition ON, verify that a 115-volt AC powered device functions when plugged into the auxiliary power outlet.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the auxiliary power outlet.
  2. Ignition ON, verify that a test lamp illuminates between the ignition voltage circuit terminal 4 and ground.
  3. If the test lamp does not illuminate, test the ignition voltage circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, disconnect the harness connectors at the accessory AC/DC power control module.
  5. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the ground circuit terminal 1 X2 and ground.
  6. If greater than the specified range, test the ground circuit for an open/high resistance.
  7. Verify that a test lamp illuminates between the B+ circuit terminal 2 X2 and ground.
  8. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  9. Ignition OFF, connect the harness connector to the auxiliary power outlet.
  10. Test for less than 2 ohms between the neutral circuit terminal 4 X1 and the neutral receptacle terminal at the auxiliary power outlet.
  11. If greater than the specified range, test the neutral circuit for an open/high resistance. If the circuit tests normal, test or replace the auxiliary power outlet.
  12. Test for infinite resistance between the neutral circuit terminal 4 X1 and ground.
  13. If less than the specified value, test the neutral circuit for a short to ground. If the circuit tests normal, test or replace the auxiliary power outlet.
  14. Test for less than 2 ohms between the phase A circuit terminal 6 X1 and the phase A receptacle terminal at the auxiliary power outlet.
  15. If greater than the specified range, test the phase A circuit for an open/high resistance. If the circuit tests normal, test or replace the auxiliary power outlet.
  16. Test for infinite resistance between the phase A circuit terminal 6 X1 and ground.
  17. If less than the specified value, test the phase A circuit for a short to ground. If the circuit tests normal, test or replace the auxiliary power outlet.
  18. Test for greater than 10 ohms between the phase A circuit terminal 6 X1 and the neutral circuit terminal 4 X1.
  19. If less than the specified value, test the phase A circuit and the neutral circuit for a shorted together condition. If the circuits test normal, test or replace the auxiliary power outlet.
  20. Connect a 115-volt AC powered device to the auxiliary power outlet.
  21. Ignition ON, verify that a test lamp illuminates between the control circuit terminal 2 X1 and ground.
  22. If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the auxiliary power outlet.
  23. If all circuits test normal, replace the accessory AC/DC power control module.

Component Testing

auxiliary power outlet

  1. Ignition OFF, disconnect the harness connector at the auxiliary power outlet.
  2. Test for less than 2 ohms between the phase A circuit terminal 6 and the phase A receptacle terminal at the auxiliary power outlet.
  3. If greater than the specified range, replace the auxiliary power outlet.
  4. Test for less than 2 ohms between the neutral outlet circuit terminal 3 and the neutral receptacle terminal at the auxiliary power outlet.
  5. If greater than the specified range, replace the auxiliary power outlet.
  6. Test for infinite resistance between the ignition voltage circuit terminal 4 and the control circuit terminal 1 at the auxiliary power outlet.
  7. If not the specified value, replace the auxiliary power outlet.
  8. Connect a 115-volt AC powered device to the auxiliary power outlet.
  9. Test for less than 2 ohms between the ignition voltage circuit terminal 4 and the control circuit terminal 1 at the auxiliary power outlet.
  10. If greater than the specified range, replace the auxiliary power outlet.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  120-Volt Accessory Power Receptacle Replacement
    •  Accessory AC and DC Power Control Module Replacement