Diagnostic Instructions
| • | 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. |
DTC Descriptors
DTC B1461 00: Left Headlamp Horizontal Motor Circuit No Additional InformationDTC B1461 02: Left Headlamp Horizontal Motor Circuit Short to Ground
DTC B1461 39: Left Headlamp Horizontal Motor Circuit Internal Electronic Failure
DTC B1461 54: Left Headlamp Horizontal Motor Circuit Temperature High
DTC B1462 00: Right Headlamp Horizontal Motor Circuit No Additional Information
DTC B1462 02: Right Headlamp Horizontal Motor Circuit Short to Ground
DTC B1462 39: Right Headlamp Horizontal Motor Circuit Internal Electronic Failure
DTC B1462 54: Right Headlamp Horizontal Motor Circuit Temperature High
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
AFL Headlamp Motor Control Circuit 1 - Left | B1461 02, 1 | B1461 00, 1 | B1461 00, 1 | B1461 39, B1461 54 |
AFL Headlamp Motor Control Circuit 2 - Left | B1461 02, 1 | B1461 00, 1 | B1461 00, 1 | B1461 39, B1461 54 |
AFL Headlamp Motor Control Circuit 3 - Left | B1461 02, 1 | B1461 00, 1 | B1461 00, 1 | B1461 39, B1461 54 |
AFL Headlamp Motor Control Circuit 4 - Left | B1461 02, 1 | B1461 00, 1 | B1461 00, 1 | B1461 39, B1461 54 |
AFL Headlamp Motor Control Circuit 1 - Right | B1462 02, 1 | B1462 00, 1 | B1462 00, 1 | B1462 39, B1462 54 |
AFL Headlamp Motor Control Circuit 2 - Right | B1462 02, 1 | B1462 00, 1 | B1462 00, 1 | B1462 39, B1462 54 |
AFL Headlamp Motor Control Circuit 3 - Right | B1462 02, 1 | B1462 00, 1 | B1462 00, 1 | B1462 39, B1462 54 |
AFL Headlamp Motor Control Circuit 4 - Right | B1462 02, 1 | B1462 00, 1 | B1462 00, 1 | B1462 39, B1462 54 |
1. Adaptive Forward Lighting Malfunction | ||||
Circuit/System Description
Battery voltage is applied to the headlamp control module at all times. The headlamp control module has a normal operational voltage range of about 12.5-16 volts and is only fully functional with the ignition switch is in the RUN position and the headlamp switch in the AUTO position. The communications enable signal from the BCM wakes the headlamp control module microprocessor. The headlamp control module receives serial data messages from the engine control module (ECM), transmission control module (TCM), electronic brake control module (EBCM), and body control module (BCM) with regards to power mode, speed, steering angle, transmission gear selection, and headlamp switch status. The headlamp control module calculates the headlamp angle and sends commands to the left and right adaptive forward lighting system (AFL) headlamp actuators. The headlamp actuators drive the headlamps to the position commanded by the headlamp control module. The headlamp control module monitors the headlamp actuator motor control circuits for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored in memory and the driver will be notified with a message displayed over the driver information center (DIC) located on the instrument panel cluster (IPC).
Conditions for Running the DTC
| • | Battery voltage must be between 9-16 volts. |
| • | Ignition is in the RUN or ON position. |
| • | Headlamp switch is in the AUTO position. |
| • | High or low beam headlamps must be active. |
| • | Vehicle speed greater than 2 mph. |
| • | Transmission is in the DRIVE position. |
Conditions for Setting the DTC
DTC B1461 00
The DTC will set when the headlamp control module detects a short to voltage or an open/high resistance on any of the left headlamp actuator control circuits.
DTC B1461 02
The DTC will set when the headlamp control module detects a short to ground on any of the left headlamp actuator control circuits.
DTC B1461 39
The DTC will set when the headlamp control module detects an internal electronic failure.
DTC B1461 54
The DTC will set when the headlamp control module detects an overheating condition on any of the left headlamp actuator control circuits.
DTC B1462 00
The DTC will set when the headlamp control module detects a short to voltage or an open/high resistance on any of the right headlamp actuator control circuits.
DTC B1462 02
The DTC will set when the headlamp control module detects a short to ground on any of the right headlamp actuator control circuits.
DTC B1462 39
The DTC will set when the headlamp control module detects an internal electronic failure.
DTC B1462 54
The DTC will set when the headlamp control module detects an overheating condition on any of the right headlamp actuator control circuits.
Actions Taken When the DTC Sets
| • | When DTC B1461 or DTC B1462 sets, the headlamp control module will attempt to return the lamps to a nominal position and disable all requests to both headlamp actuators. |
| • | The driver information center (DIC) will display Service AFS Lamps. |
| • | On vehicles equipped with both AFL and headlamp leveling, the headlamp leveling system will be disabled. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear once 50 consecutive malfunction-free cycles have occurred. |
Diagnostic Aids
Diagnose any faults to the vehicle stability enhancement system (VSES) which contains the steering wheel position sensor before proceeding with this diagnostic procedure. A fault within the steering wheel position sensor will cause the adaptive forward lighting system to be inoperative.
Reference Information
Schematic Reference
Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, with a scan tool, command the headlamp motor test ON while observing both headlamps. Both headlamps should operate to the LEFT and RIGHT positions when commanded.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate headlamp actuator.
- Ignition OFF, test for less than 10 ohms between the control circuit terminal 1 and ground.
- Ignition OFF, test for less than 10 ohms between the control circuit terminal 2 and ground.
- Ignition OFF, test for less than 10 ohms between the control circuit terminal 3 and ground.
- Ignition OFF, test for less than 10 ohms between the control circuit terminal 4 and ground.
- Connect a test lamp between control circuit terminal 1 and control circuit terminal 3.
- Command the Headlamp Motor Test ON with a scan tool. The test lamp should turn ON when commanding the Left and Right states.
- Connect a test lamp between control circuit terminal 2 and control circuit terminal 4.
- Command the Headlamp Motor Test ON with a scan tool. The test lamp should turn ON when commanding the Left and Right states.
- If all circuits test normal, replace the appropriate headlamp assembly.
| ⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the headlamp control module. |
| ⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the headlamp control module. |
| ⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the headlamp control module. |
| ⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the headlamp control module. |
| ⇒ | If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the headlamp control module. |
| ⇒ | If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the headlamp control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for headlamp control module replacement, setup, and programming |
