C1276

Diagnostic Chart:

Serial Data Schematic:

CIRCUIT DESCRIPTION
The serial data link is a communication line between the Powertrain Control Module (PCM), Electronic Brake/Traction Control Module (EBCM/EBTCM), and other system controllers.

The EBTCM shares specific serial data information supplied on the data line. The data line also allows the use of a bi-directional scan tool.

CONDITIONS FOR SETTING THE DTC
DTC C1276 can be set anytime the ignition is in RUN. A malfunction exists if CKT 800 is open or shorted to ground resulting in no communication to the PCM or any other controller.

A current DTC C1276 cannot be read with a scan tool due to the loss of serial data communications. After data line communications are restored, DTC C1276 will be stored in memory.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, TCS is disabled and the TRACTION OFF indicator lamp is turned ON.

CONDITIONS FOR CLEARING THE DTC
^ Conditions for the malfunction are no longer present and scan tool clear DTCs function is used.
^ 100 ignition switch key cycles have passed with no malfunctions detected.

DIAGNOSTIC AIDS
The malfunction may be intermittent. Try performing the tests shown while "wiggling" wiring and connectors, this can often cause the malfunction to appear. A PCM DTC will likely be set along with DTC C1276.

A thorough inspection of Grounds G101, G102, G106, and G110 should be performed.

DTC C1276 will only be able to be read as a history code since the scan tool uses the same serial data circuit. If CKT 800 is shorted to ground, or open, no communication with the scan tool will be possible.