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 |
|---|---|---|---|---|
Hazard Switch Signal | 1 | 3 | 3 | -- |
Left Front Turn Signal Lamp Supply Voltage | B3948 02 | B3948 05 | B3948 05 | -- |
Right Front Turn Signal Lamp Supply Voltage | B3949 02 | B3949 05 | B3949 05 | -- |
Left Rear Stop/Turn Signal Lamp Supply Voltage | B3950 02 | B3950 05 | B3950 05 | -- |
Right Rear Stop/Turn Signal Lamp Supply Voltage | B3951 02 | B3951 05 | B3951 05 | -- |
Left Turn Signal Switch Signal | 1 | 2 | -- | -- |
Right Turn Signal Switch Signal | 1 | 2 | -- | -- |
Left Rear Stop/Turn Lamp Ground | -- | 2 | 2 | -- |
Right Rear Stop/Turn Lamp Ground | -- | 2 | 2 | -- |
Turn Signal/Multifunction Switch Ground | -- | 2 | 2 | -- |
Turn Signal Lamp - LF Ground | -- | 2 | 2 | -- |
Turn Signal Lamp - RF Ground | -- | 2 | 2 | -- |
1. Turn Signal Lamps and/or Indicators Always On or Flashing 2. Turn Signal Lamps and/or Indicators Inoperative 3. Hazard Lamps Inoperative | ||||
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.
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
Turn Signal Lamps Inoperative - One
- Ignition ON, turn ON the hazard lamps and observe the turn signal lamps and indicators.
- Ignition OFF, disconnect the inoperative turn signal lamp.
- Connect a test lamp between the inoperative turn signal lamp supply voltage circuit and ground.
- Ignition ON, turn ON the hazard lamps. The test lamp should illuminate.
- Verify that a test lamp illuminates between battery voltage and the inoperative turn signal lamp ground circuit.
- If all circuits test normal, replace the turn signal lamp.
| ⇒ | If only the turn signal indicators are inoperative, replace the instrument panel cluster (IPC). |
| ⇒ | 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. |
| ⇒ | If the test lamp does not illuminate, repair the affected turn signal lamp ground circuit for an open/high resistance. |
Turn Signal Lamps Inoperative - All
- Ignition ON, turn ON the hazard lamps and observe the turn signal lamps and indicators.
- Ignition OFF, disconnect the turn signal/multifunction switch C2 harness connector.
- Verify that a test lamp illuminates between battery voltage and the turn signal/multifunction switch turn signal ground circuit.
- Connect a 3-amp fused jumper between the left turn signal switch signal circuit and ground.
- Ignition ON, the left turn signal lamps should illuminate.
- Ignition OFF, connect a 3-amp fused jumper between the right turn signal switch signal circuit and ground.
- Ignition ON, the right turn signal lamps should illuminate.
- If all circuits test normal, test or replace the turn signal/multifunction switch.
| ⇒ | If all turn signal lamps are inoperative, replace the BCM. |
| ⇒ | If only the turn signal indicators are inoperative, replace the IPC. |
| ⇒ | 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. |
| ⇒ | 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. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM and IPC replacement, setup, and programming |
