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B1461



DTC B1461

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.



DTC Descriptors
DTC B1461 00
- Left Headlamp Horizontal Motor Circuit No Additional Information

DTC 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




Circuit/System Description

Battery positive voltage is applied to the headlamp control module at all times and when the ignition switch is in the RUN and CRANK positions. The headlamp control module has an operational voltage range of about 10.5-16 volts and is only fully functional when the ignition switch is in the RUN position. The voltage input from the ignition switch wakes the headlamp control module microprocessor. The headlamp control module receives serial data messages via GMLAN 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 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

The headlamp control module performs this diagnostic test mode every 250 milliseconds when the following conditions are met:

* Battery voltage must be between 10-16 volts.
* Ignition is in the RUN 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

This DTC will set when the headlamp control module detects an open or short to voltage in the right headlamp actuator control circuits.

DTC B1461 02

This DTC will set when the headlamp control module detects a short to ground in the right headlamp actuator control circuits.

DTC B1461 39

This DTC will set when the headlamp control module detects an internal circuit failure.

DTC B1461 54

This DTC will set when the headlamp control module detects a high temperature condition in the right headlamp actuator control circuits.


Action Taken When the DTC Sets

When DTC B1461 sets, the headlamp control module will disable all requests to both headlamp actuators and headlamp position will be maintained.


Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* You issue a scan tool CLEAR DTCs command.
* A history DTC will clear once 40 consecutive malfunction-free ignition cycles have occurred.



Reference Information
Schematic Reference

Headlights/Daytime Running Lights (DRL) Schematics (Headlights/Daytime Running Lights (DRL) Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)


Circuit/System Testing


DTC B1461 00
1. Ignition OFF, disconnect the headlamp control module harness connector.
2. Ignition ON, verify that a test lamp does not illuminate between ground and each LH AFS motor control circuit one at a time.

If the test lamp illuminates, repair the effected LH AFS motor control circuit for a short to voltage.

3. Ignition OFF, test each LH AFS motor control circuit for good continuity.

If good continuity is not detected, repair the affected LH AFS motor control circuit for shorts to each other, or an open/high resistance. If the circuits test normal, test or replace the LH AFS motor.

4. If all circuits test normal, replace the headlamp control module.



DTC B1461 02
1. Ignition OFF, disconnect the headlamp control module harness connector.
2. Verify that a test lamp does not illuminate between battery positive voltage and each LH AFS motor control circuit one at a time.

If the test lamp illuminates, repair the effected LH AFS motor control circuit for a short to ground. If the circuits test normal, test or replace the LH AFS motor.

3. If all circuits test normal, replace the headlamp control module.



DTC B1461 39
1. Ignition ON, install a scan tool and clear all DTCs.
2. Operate the vehicle within the conditions for running the DTC.
3. With the scan tool, retrieve DTCs and determine if DTC B1461 39 has reset as current.

If DTC B1461 39 resets as a current DTC, replace the headlamp control module.




DTC B1461 54
1. Ignition ON, install a scan tool and clear all DTCs.
2. Operate the vehicle within the conditions for running the DTC.
3. With the scan tool, retrieve DTCs and determine if DTC B1461 54 has reset as current.

If DTC B1461 54 resets as a current DTC, replace the headlamp control module.




Repair Instructions

Always perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Headlamp Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for headlamp control module replacement, setup, and programming