Torque Management Signal (CCD Broadcast)

With some engines, the TCM sends a direct input, torque management request signal to: the PCM. This occurs during high torque, high speed 1-2, 2-3, 4-2 and 3-1 shifts. The TCM torque management request signal is used in order to reduce the torque applied in the 2-4 and OD clutches. The PCM uses the TCM's torque management signal to shut off a certain number of fuel injectors and to retard ignition timing slightly. This controls or reduces torque output of the engine during certain shift sequences. The torque reduction is not detectable by the driver and lasts for a very short time period. The PCM sends a confirmation of the request to the TCM over the CCD Bus. If the confirmation signal is not received by the TCM, a diagnostic trouble code will eventually be set.

The torque management signal is basically a 9-volt supply to the PCM. A torque management request is recognized by the PCM when the TCM grounds the circuit. The circuit at the TCM is called TRD link, which stands for "Torque Reduction Link."