Diagnostic Routine R

Diagnostic Routine R

Diagnostic Overview

One Turn Signal Lamp Is Inoperative Or Always On

Refer to Wiring Diagram Set 90 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

REFER to Turn Signals .

DTC Fault Trigger Conditions






Visual Inspection and Diagnostic Pre-checks

- Inspect the turn lamp bulb and make sure it is OK.

- Inspect the BCM (Body Control Module) fuses 14 (10A) (left turn lamps) and 13 (15A) (right turn lamps).

- Inspect the headlamp assembly, exterior rear view mirror or rear lamp assembly for damage.

Pinpoint Test

1. DETERMINE IF A TURN LAMP IS ALWAYS ON

1. Ignition ON.

2. Observe the turn lamps.

Is any turn lamp always on?








2. CHECK THE TURN LAMP OUTPUT CIRCUITS FOR A SHORT TO VOLTAGE

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280F (front or exterior mirror turn lamp).

3. Disconnect: BCM (Body Control Module) C2280C (rear turn lamp).

4. Ignition ON.

Does the turn lamp in question continue to illuminate?








3. CHECK FOR VOLTAGE TO THE INOPERATIVE TURN LAMP

1. Ignition OFF.

2. Disconnect: Inoperative Turn Lamp.

3. Activate the hazard lamp function.

4. For a front turn lamp, measure:





5. For an exterior mirror turn lamp, measure:





6. For a rear turn lamp, measure:





Does the voltage alternate between 0 and greater than 11 volts?








4. CHECK THE TURN LAMP GROUND CIRCUIT FOR AN OPEN

1. For a front turn lamp, measure:





2. For an exterior mirror turn lamp, measure:





3. For a rear turn lamp, measure:





Does the voltage alternate between 0 and greater than 11 volts?








5. ISOLATE THE HEADLAMP, EXTERIOR MIRROR OR REAR LAMP JUMPER HARNESS FOR A SHORT TO GROUND

1. Deactivate the hazard lamp function.

2. Ignition ON.

3. Using a scan tool, clear the DTCs (Diagnostic Trouble Codes) and repeat the BCM (Body Control Module) on-demand self-test (required to enable the turn lamp output driver if DTC (Diagnostic Trouble Code) U1000:00 is present).

4. Activate the hazard lamp function.

5. For a front turn lamp, measure:





6. For an exterior mirror turn lamp, measure:





7. For a rear turn lamp, measure:





Does the voltage alternate between 0 and greater than 11 volts?








6. CHECK THE BCM (Body Control Module) TURN LAMP OUTPUT CIRCUIT FOR A SHORT TO GROUND

1. Ignition OFF.

2. Deactivate the hazard lamp function.

3. Disconnect BCM (Body Control Module) C2280F (front or exterior mirror turn lamp).

4. Disconnect BCM (Body Control Module) C2280C (rear turn lamp).

5. For a front turn lamp, measure:





6. For an exterior mirror turn lamp, measure:





7. For a rear turn lamp, measure:





Is the resistance greater than 10,000 ohms?








7. CHECK THE BCM (Body Control Module) TURN LAMP OUTPUT CIRCUIT FOR AN OPEN

1. For a front turn lamp, measure:





2. For an exterior mirror turn lamp, measure:





3. For a rear turn lamp, measure:





Is the resistance less than 3 ohms?








8. CHECK FOR CORRECT BCM (Body Control Module) OPERATION

1. Disconnect and inspect all BCM (Body Control Module) connectors.

2. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged or bent pins- install new terminals/pins
- pushed-out pins- install new pins as necessary

3. Reconnect the BCM (Body Control Module) connectors. Make sure they seat and latch correctly.

4. Operate the system and determine if the concern is still present.

Is the concern still present?