• | 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Body Control Module (BCM) 3 Fuse B+ | 1 | 1 | -- | -- |
Body Control Module (BCM) 5 Fuse B+ | 1 | 1 | -- | -- |
Body Control Module (BCM) 6 Fuse B+ | 1 | 1 | -- | -- |
Hazard Switch Signal | 2 | 2 | 2 | -- |
Left Tail Lamp Outage Detection Signal | 4 | 4 | 4 | -- |
Left Turn Signal Switch Signal | 3 | 3 | 3 | -- |
Right Tail Lamp Outage Detection Signal | 4 | 4 | 4 | -- |
Right Turn Signal Switch Signal | 3 | 3 | 3 | -- |
Left Front Turn Signal Lamp Control | 1 | 1 | 1 | -- |
Right Front Turn Signal Lamp Control | 1 | 1 | 1 | -- |
Left Rear Turn Lamp Control | 1 | 1 | 1 | -- |
Right Rear Turn Lamp Control | 1 | 1 | 1 | -- |
Hazard Switch Ground | -- | 2 | -- | -- |
Left Rear Stop/Turn Lamp Ground | -- | 1 | -- | -- |
Left Repeater Lamp Ground | -- | 1 | -- | -- |
Right Repeater Lamp Ground | -- | 1 | -- | -- |
Right Rear Stop/Turn Lamp Ground | -- | 1 | -- | -- |
Turn Signal/Multifunction Switch Ground | -- | 3 | -- | -- |
Turn Signal Lamp - LF Ground | -- | 1 | -- | -- |
Turn Signal Lamp - RF Ground | -- | 1 | -- | -- |
1. Turn Signal Lamps and/or Indicators Malfunction 2. Hazard Lamps Malfunction 3. Turn Signal Switch Malfunction 4. Tail Lamp Outage Detection Malfunction |
Ground is applied at all times at G200 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. The BCM then applies a pulsating voltage to the front and rear turn signal lamps through there respective voltage supply circuits. Ground for the left and right front turn signal lamp is supplied at G104. Ground for the rear turn signal lamps is supplied at G402 for the left and G401 for the right.
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
The tail lamp outage detection circuits are low current B+ circuits supplied by the BCM. For purposes of testing, a test lamp connected between the outage detection circuit and ground will not illuminate due to the low current.
⇒ | If the readings do not change between the commanded states, refer to Turn Signal Switch Malfunction. |
⇒ | If the readings change between the commanded states and the turn signal indicators are inoperative, refer to Turn Signal Indicators Malfunction. |
⇒ | If the left turn signal lamps and indictors illuminate but flash in a rapid manner, refer to Tail Lamp Outage Detection Malfunction. |
⇒ | If the left turn signal lamps and indictors illuminate but flash in a rapid manner, refer to Tail Lamp Outage Detection Malfunction. |
⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. |
⇒ | If not the specified value, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. |
⇒ | If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
Ignition ON, with a scan tool perform the Display Test for the instrument panel cluster (IPC) and observe the turn signal lamp indicators.
⇒ | If the turn signal lamp indicators illuminate during the test, replace the BCM. |
⇒ | If the turn signal lamp indicators do not illuminate during the test or remain illuminated at all times, replace the IPC. |
⇒ | If not the specified value, replace the tail lamp assembly. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM or IPC replacement, setup, and programming |