Self-Diagnostic System: Notes

NOTE: Use of scan tool is required for reading DTC(s). TBC module does not turn on SERVICE ENGINE SOON MIL. It will turn on the SECURITY indicator light for PassLock(R) system related malfunctions.

Truck Body Control (TBC) module is equipped with a self-diagnostic system, which detects system Diagnostic Trouble Codes (DTCs) or abnormalities. When a malfunction occurs, TBC will store a DTC. See TBC MODULE DTC DEFINITIONS . Malfunctions are recorded as history/intermittent failures or as current failures.

Current DTCs indicate TBC module has detected a fault which is currently present. A history DTC indicates that TBC module has previously detected a malfunction that is not currently present.

A scan tool must be used to retrieve and clear DTCs. The scan tool also has several features that can be used to help locate an intermittent condition.