Interface to Petrol Engine Control Module (ECM) (Z132)

The Auto Gear Box Control Unit (Z255) takes the engine torque, engine speed and throttle angle signals from the ECM, calculates which gear is required, outputs to the solenoid valves and sends a torque reduction signal back to the ECM, thereby retarding the ignition point on each of the cylinders and so giving a reduction in engine power during gear changes that result in a smooth change.

The engine torque is received by the Auto Gear Box Control Unit (Z255) on its pin 21, the engine speed on pin 3 and the throttle angle on pin 47. The torque reduction signal is sent to the ECM from the Auto Gear Box Control Unit (Z255) via its pin 32.