Auto Headlamp Leveling Module (AHLM)

B2199-16-BATTERY VOLTAGE - CIRCUIT VOLTAGE BELOW THRESHOLD





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

- When Monitored:
Continuously with the ignition on.

- Set Condition:
The Automatic Headlamp Leveling Module (AHLM) senses voltage input below 9.0 volts for over 15 seconds.





1. RELATED DTC(S) PRESENT IN PCM
1. Turn the ignition on.
2. With the scan tool, select View DTCs in the Powertrain Control Module (PCM).

Are there any charging system or related battery voltage DTCs present in the PCM?

Yes

- Perform the appropriate diagnostic procedure. Testing and Inspection.

No

- Go To 2

2. CHECK FOR AN ACTIVE DTC
1. With the scan tool, read AHLM DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 3

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.

3. (F921) FUSED RUN RELAY OUTPUT CIRCUIT




1. Turn the ignition off.
2. Disconnect the Right Front Headlamp Assembly C2 harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (F921) Fused Run Relay Output circuit.

Is battery voltage present?

Yes

- Replace the Automatic Headlamp Leveling Module (AHLM). Headlamp Leveling Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Repair the (F921) Fused Run Relay Output circuit for an open, short to ground, or high resistance
- Perform the BODY VERIFICATION TEST. Body Verification Test.