Turn Signal Lamps and/or Indicators Inoperative

TURN SIGNAL LAMPS AND/OR INDICATORS INOPERATIVE




DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

CIRCUIT/SYSTEM DESCRIPTION
Ground is applied at all times at G201 to the turn signal/multifunction switch. The turn signal lamps may only be activated with the ignition switch in the ON or START position. When the turn signal/multifunction switch is placed in either the TURN RIGHT or TURN LEFT position, ground is applied to the body control module (BCM) through either the right turn or left turn signal switch signal circuit. Battery voltage is applied at all times from the BATT MAIN 3 fuse to the BCM. The BCM then applies a pulsating voltage to the front and rear turn signal lamps. Ground for the left front turn signal lamp is supplied at G101. Ground for the right front turn signal lamp is supplied at G102. Ground for the left rear turn signal lamp is supplied at G400. Ground for the right rear turn signal lamp is supplied at G402.

CIRCUIT/SYSTEM TESTING

Turn Signal Lamps Inoperative - One
1. Ignition ON, turn ON the hazard lamps and observe the turn signal lamps and indicators.
- If only the turn signal indicators are inoperative, replace the instrument panel cluster (IPC).
2. Ignition OFF, disconnect the inoperative turn signal lamp.
3. Connect a test lamp between the inoperative turn signal lamp supply voltage circuit and ground.
4. Ignition ON, turn ON the hazard lamps. The test lamp should illuminate.
- If the test lamp does not illuminate, repair the affected turn signal lamp voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. Verify that a test lamp illuminates between battery voltage and the inoperative turn signal lamp ground circuit.
- If the test lamp does not illuminate, repair the affected turn signal lamp ground circuit for an open/high resistance.
6. If all circuits test normal, replace the turn signal lamp.

Turn Signal Lamps Inoperative - All
1. Ignition ON, turn ON the hazard lamps and observe the turn signal lamps and indicators.
- If all turn signal lamps are inoperative, replace the BCM.
- If only the turn signal indicators are inoperative, replace the IPC.
2. Ignition OFF, disconnect the turn signal/multifunction switch C2 harness connector.
3. Verify that a test lamp illuminates between battery voltage and the turn signal/multifunction switch turn signal ground circuit.
- If the test lamp does not illuminate, repair the turn signal/multifunction switch turn signal ground circuit for a short to voltage or an open/high resistance.
4. Connect a 3-amp fused jumper between the left turn signal switch signal circuit and ground.
5. Ignition ON, the left turn signal lamps should illuminate.
- If the left turn signal lamps do not illuminate, repair the left turn signal switch signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
6. Ignition OFF, connect a 3-amp fused jumper between the right turn signal switch signal circuit and ground.
7. Ignition ON, the right turn signal lamps should illuminate.
- If the right turn signal lamps do not illuminate, repair the right turn signal switch signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
8. If all circuits test normal, test or replace the turn signal/multifunction switch.

REPAIR INSTRUCTIONS

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

- Park/Turn Signal Lamp Bulb Replacement
- Multifunction, Turn Signal Switch Replacement
- Control Module References for BCM and IPC replacement, setup, and programming