ABS - Integrated Chassis Control

DTC C1276: Delivered Torque Signal Circuit Malfunction (Part 1 Of 2):

DTC C1276: Delivered Torque Signal Circuit Malfunction (Part 2 Of 2):

DTC C1276 Schematic:

CIRCUIT DESCRIPTION
Traction Control is simultaneously controlled by the EBTCM and the PCM. The PCM sends a DELIVERED TORQUE message via a Pulse Width Modulated (PWM) signal to the EBTCM confirming the delivered torque level for proper Traction Control system operation. The EBTCM supplies the pull up voltage.

CONDITION FOR SETTING THE DTC
DTC C1276 can be set anytime when ignition voltage is present. A malfunction exists if the PWM signal is out of range or no signal is received for a period of 7 seconds.

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

CONDITIONS FOR CLEARING THE DTC
Condition for DTC is no longer present and scan tool clear DTC function is used. Fifty start cycles have passed with no DTCs detected.

DIAGNOSTIC AIDS
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. Possible causes; Open in CKT 464, CKT 464 shorted to ground or voltage, and Communication frequency problem.

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
4. Checks for proper PWM duty cycle.
5. Checks for proper frequency.
6. Check delivered torque voltage input to the EBTCM.
8. Check for a short to B+ in CKT 464.
10. Check for a short to ground in CKT 464.
12. Check for an open in CKT 464.