For a complete wiring diagram Refer to Section 8W.Communication over the CAN bus is continuously monitored between the Engine Control System and the Transmission Control System. Due to the integration of both systems into one module (NGC3), (Powertrain Control Module) the bus communication between the systems is internally transmitted over the duel port ram. The NGC4 controller contains only one processor. This DTC will set if the NGC4 controller (transmission only) is used in conjunction with an Engine Controller (ECM).When Monitored:Every 7 msec. with the ignition on.Set Condition:ECM/PCM CAN bus message not received by the Transmission Control System for the period of 10 seconds. Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING for diagnostic procedures and for further possible causes.