Powertrain Controls - ECM/PCM

DTC 81 Brake Switch Error:

Brake Switch Wiring Diagram:

Circuit Description:

The ECM monitors the status of the brake switch circuit through ECM terminal "A18".

DTC 81 will set if:

^ Vehicle speed has been greater than or equal to 35 mph for 10 seconds and back to 0 mph for four times or more.

^ Status of CKT 583 has not changed from "Released" to "Applied" or "Applied" to Released" as displayed on the scanner.

Diagnostic Aids:


A DTC 81 can be caused by a misadjusted brake switch or a poor connection.

NOTICE: If the brake switch has failed in an open state, TCC will not engage.