CAN Bus Switching (Automatic gearbox - Jatco)

CAN Bus Switching

EAT ECU CAN Messages The following table lists CAN message inputs and outputs from and to the EAT ECU.

CAN Inputs l Actual engine torque. This message from the ECM indicates the actual engine torque produced at any one time. The EAT ECU uses this message to control gear shift scheduling. l Engine coolant temperature. This message from the ECM is used by the EAT ECU for OBD diagnostic functions and to detect when the engine has completed a 'warm up' cycle. l Engine friction. This message from the ECM is the current frictional torque losses within the engine and is expressed as a percentage of maximum engine torque. The EAT ECU uses this message to control gear shift scheduling. l Engine speed. This message from the ECM is used by the EAT ECU to calculate gearbox oil pressure to assist control of gear shift scheduling. l Engine speed signal error. This message from the ECM informs the EAT ECU if there is a fault with the engine speed calculation. If necessary, the EAT ECU then adjusts gearbox operation to prevent possibility of mechanical damage. l Engine torque error. This message from the ECM informs the EAT ECU that torque values received are incorrect and there is an ECM torque measurement error. l Estimated engine torque This message from the ECM informs the EAT ECU of the level of torque that the engine is producing. The EAT ECU uses this message to control gearshift scheduling. l Ignition switch status. This message from the ECM is produced when the ECM energises the main relay. The EAT ECU uses this message to initiate the power-down routine at ignition off. l Actual engine torque. This message from the ECM is the theoretical engine torque for current throttle setting and engine operating conditions. This is the same as the actual engine torque unless torque reduction in progress and is expressed as a percentage of maximum engine torque. The EAT ECU uses this message to control gear shift scheduling. l Throttle angle. This message from the ECM informs the EAT ECU of the throttle angle (driver demand). The EAT ECU uses this message to control gear shift scheduling.