B2575

B2575 - Headlamp Control Circuit Malfunction

Schematic:

CIRCUIT DESCRIPTION
The body control module (BCM) monitors circuit 74 to determine if the headlamp (parklamp) switch is active or inactive. The automatic light control (ALC) system will be inactive if the headlamp parklamp switch is active. The headlamp relay is commanded on by the BCM through circuit 352. The BCM also monitors circuit 352 for feedback when the headlamp relay is commanded. If the feedback does not change when the headlamp relay driver in the BCM switches to ground then fail DTC B2575. The BCM has to be in the ALC mode with light sensor indicating that a dark condition exists.

DTC PARAMETERS
^ Headlamp relay is On.
^ Low Beam lamps are Off.
^ High Beam Lamps are Off
^ Ignition is in RUN.
^ Condition is present for 5 seconds.
^ No telltale Illumination.

DIAGNOSTIC AIDS
^ Check for poor connection at the BCM. Inspect harness connectors for backed-out terminals, improper terminal mating, broken connector locks, improperly formed or damaged terminals and poor terminal-to-wire connection (terminal crimped over wire insulation and not conductors).
^ Inspect wiring harness for damage. Check for broken or chaffed insulation.
^ If fault is suspected to be intermittent, wiggling harness wiring may help in locating fault.

TEST

Diagnostic Chart: