Auto Headlamp Leveling Module (AHLM)
B210B-SYSTEM VOLTAGE HIGH
For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
- When Monitored:
At all times.
- Set Condition:
When the Front Control Module (FCM) sends a message to the AHLM Module that the input voltage of the vehicle is above 16 volts for over 15 seconds, this code will set.
1. CHECK POWERTRAIN CONTROL MODULE (PCM) or ENGINE CONTROL MODULE (ECM) DTCs
1. With the scan tool, read the PCM or ECM DTCs.
Are there any BATTERY OR CHARGING SYSTEM DTCs present?
Yes
- For gas engine applications, Testing and Inspection Perform the appropriate diagnostic procedure.
No
- Go To 2
2. TEST FOR INTERMITTENT CONDITION
1. With the scan tool, record and erase the DTCs
2. Start the engine and run for two minutes.
3. With the scan tool, read the DTCs in the Headlamp Leveling Module (AHLM).
Does the scan tool display B210B-SYSTEM VOLTAGE HIGH?
Yes
- Go To 3
No
- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
3. CHECK THE HEADLAMP LEVELING MODULE (AHLM) HARNESS VOLTAGE
1. Stop the engine.
2. Turn the ignition on.
3. Using the scan tool, read and record the Battery Voltage of the Headlamp Leveling Module.
4. Turn the ignition off.
5. Disconnect the Headlamp Leveling Module connector.
6. Turn the ignition on.
7. Using a voltmeter, measure the voltage between the (F921) Fused Ignition Switch Output circuit and the (Z919) Ground in the Headlamp Leveling Module connector.
Does the measured voltage differ from the scan tool voltage by more than one (1.0) volt?
Yes
- Replace the Headlamp Leveling Module (AHLM).
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Compare this voltage reading to direct battery voltage. If the voltage differs by more than one volt, repair the wiring. If not - test complete.
- Perform the BODY VERIFICATION TEST. Body Verification Test.