DTC B2577: ALC Headlight Relay Output Short To Ground/Open: Description

DTC B2577 indicates that ALC headlight relay output is shorted to ground or open. DTC B2577 will set when ambient light sensor indicates bright conditions, ALC option is enabled and Ignition 1 is active, engine is not being cranked ("Ignition 1 active, Ignition 3 inactive and engine not running" class 2 data message), ALC headlight output is not active and ALC headlight feedback exists for 5 seconds.

When DTC B2577 is set, SERVICE VEHICLE SOON indicator will illuminate. DTC B2577 can be cleared when BFC reads proper headlight voltage or using scan tool. History DTC will disappear after 100 ignition cycles if fault conditions do not reoccur.

DTC B2577 indicates that ALC headlight relay output is shorted to ground or open. DTC B2577 will set when ambient light sensor indicates bright conditions, ALC option is enabled and Ignition 1 is active, engine is not being cranked ("Ignition 1 active, Ignition 3 inactive and engine not running" class 2 data message), ALC headlight output is not active and ALC headlight feedback exists for 5 seconds.

When DTC B2577 is set, SERVICE VEHICLE SOON indicator will illuminate. DTC B2577 can be cleared when BFC reads proper headlight voltage or using scan tool. History DTC will disappear after 100 ignition cycles if fault conditions do not reoccur.