D Group 28 Design and Function Transmission Electronic Control Unit The TECU communicates with the Gear Selector ECU and other ECUs in the vehicle through the J1939 and J1587 data buses. The functionality of the TECU can be different depending on the type of software packages that are installed. The TECU contains the following components: SAE J11708/1587 CAN SAE J1939 CAN Powertrain CAN 11 Powerdrivers Inclination Sensor Temperature Sensor 9 Controlling Solenoid Valves The Transmission Electronic Control Unit located on the upper portion of the control housing. Lubrication System The transmission is lubricated through a combination of pressure from an oil pump and splashing.
The oil is led into the main shaft to lubricate and cool the range gears, the input shaft and main shaft bearings. The countershaft brake and output shaft bearings, are also lubricated. The lubrication system has two overflow valves. One valve ensures that the transmission is lubricated if the filter gets blocked while the other prevents excessive pressure in the system, e.g. during cold start. The valves are made up of a compression spring and a valve peg. 10