B2575

DTC B2575 Headlamp Request/Feedback Mismatch:

DTC B2575 Headlamp Request/Feedback Mismatch (Part 1 Of 2):

DTC B2575 Headlamp Request/Feedback Mismatch (Part 2 Of 2):

CIRCUIT DESCRIPTION

This is a trouble code (both current and history) that indicates that the headlamps were not on when the Automatic Lighting Control(ALC) Relay output was ON.

CONDITIONS FOR SETTING THE DTC

Meet all of the following conditions:

^ The ALC headlamp relay output is active
^ The ALC option is enabled and ignition 1 is active
^ The high beams are either OFF or in DRL mode
^ The low beams are OFF for 5 seconds

ACTION TAKEN WHEN THE DTC SETS

^ Stores the DTC B2575 in the Body Control Module (BCM) memory.
^ The SERVICE VEHICLE SOON indicator illuminates.
^ The check gauges chime sounds.

CONDITIONS FOR CLEARING THE DTC

^ The BCM reads the proper headlamp voltage.
^ Conditions for the fault are no longer present.
^ All the BCM history codes will be cleared after 100 ignition cycles (from OFF to ON) with no current codes active during the 100 ignition cycles.
^ Use the Scan Tool.

DIAGNOSTIC AIDS

^ Turn the ignition switch to the ON position, cover the ambient light sensor on the dash, and wait for 8 seconds. The low beams should illuminate. If the low beams do not illuminate, refer to Headlight: Daytime Running Lights, in Lighting Systems.
^ Turn the Ignition Switch to the ON position, activate the High Beams, and cover the Ambient Light Sensor on the dash then wait for 8 seconds. The High Beams should illuminate. If the High Beams do not illuminate refer to Headlight: Daytime Running Lights, in Lighting Systems.
^ If the DTC is a history DTC, the problem may be intermittent. Try performing the tests shown while wiggling the wires and connectors; this can often cause the malfunction to appear.

TEST DESCRIPTION

The numbers below refer to the numbers on the diagnostic table.

4. This step tests to see it the Body Control Module (BCM) is receiving the input which indicates that the low beam headlamps are working properly.
6. This step determines if the underhood wiring harness junction block has a short to ground and whether the Body Control Module (BCM) is receiving the input which indicates that the low beam headlamps are working properly.