Detroit DD15 GHG14 (2014-16) Fault Code: SPN 1121 FMI 19 (CPC) Service Brake Switch Signal from EBC1 is Erratic

NOTE: Please see the step by step troubleshooting procedures for this specific code.

NOTE: If codes 168-0, 168-14, or 168-18 are present, fix those first.

NOTE: If code 625-9 is present, fix that first.

NOTE: If the ECM hasn’t been configured or programmed recently, then check all other modules on the truck (Cab, ABS, Transmission, etc…) for errors. Repair those as needed.