B17A5-15

B17A5-15-HALO LAMPS CONTROL - CIRCUIT SHORT TO BATTERY OR OPEN





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Body Control Module (BCM) provides a battery voltage output to certain low-level lighting output lamps through the ambient lamp driver circuit. These lamps use a dedicated path to ground for illumination. For additional information on the operation of the lamps, Interior Lighting - Operation.

- When Monitored:
With the Ambient Lamp Driver commanded off.

- Set Condition:
When the Body Control Module (BCM) detects a high condition on the (M5) Ambient Lamp Driver circuit.





1. INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. Rotate the Ambient Light Dimmer Switch to DEFEAT.
4. With the scan tool, read DTCs.

Does the scan tool display DTC: B17A5-15-HALO LAMPS CONTROL - CIRCUIT SHORT TO BATTERY OR OPEN?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE (M5) AMBIENT LAMP DRIVER CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS
1. Turn the ignition off.
2. Disconnect the Left and Right Map Pocket Lamp harness connectors.
3. Disconnect the BCM F and G harness connectors.
4. Turn the ignition on.
5. Measure the voltage between ground and the (M5) Ambient Lamp Driver circuit.

Is there any voltage present?

Yes

- Repair the short to voltage in the (M5) Ambient Lamp Driver circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 3

3. CHECK THE (M5) AMBIENT LAMP DRIVER CIRCUIT FOR AN OPEN IN THE HARNESS
1. Turn the ignition off.
2. Measure the resistance of the (M5) Ambient Lamp Driver circuit between the Left Map Pocket Lamp harness connector and the BCM F and G harness connectors.
3. Measure the resistance of the (M5) Ambient Lamp Driver circuit between the Right Map Pocket Lamp harness connector and the BCM F and G harness connectors.

Are the resistances below 5.0 Ohms?

Yes

- Go To 4

No

- Repair the open in the (M5) Ambient Lamp Driver circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

4. CHECK THE (Z921) AND (Z922) GROUND CIRCUIT FOR AN OPEN IN THE HARNESS
1. Using a 12-volt test light connected to 12-volts, check the (Z921) and (Z922) Ground circuits.

Does the test light illuminate brightly?

Yes

- Go To 5

No

- Repair the open in the (Z921) or (Z922) Ground circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

5. CHECK THE BCM FOR CORRECT OPERATION
1. Turn the ignition off.
2. Reconnect the BCM F and G harness connectors.
3. Connect a 12-volt test light between the (M5) Ambient Lamp Driver circuit and the (Z921) Ground circuit at the Left Map Pocket Lamp harness connector.
4. Turn the ignition on.
5. Rotate the Ambient Light Dimmer Switch to full brightness.

Does the test light illuminate brightly?

Yes

- Replace the lamp causing the short to voltage or open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the BCM. Body Control Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.