Function of individual components · 1. Upshift and downshift switches 4. Coolant changeover valve

911 Carrera (996) Tiptronic diagnosis .. Function of individual components 1. Upshift and downshift switches 4. Coolant changeover valve Installationposition:In the steeringwheel Installationposition: On the engine (transport eye). In the manual gate, they connect ground Dependingon the ATF and coolant to the Tiptronic control module, which temperature, the changeovervalve is initiates upshifting or downshifting, activated by the Tiptronic control module depending on the speed. and routes vacuum to the shutoff valve, which opens or closes the transmission 2. DME control module coolant circuit. Installationposition: In the passenger 5. Multi-function switch compartment behind the right-hand emergency seat recess. Installationposition: On the transmission. The DME control module is connected The multi-functionswitch is actuated directly to the Tiptronic control module. It transmits the by the selector lever via a cable and transmits following informationvia a control line (CANbus): the selector lever position to the transmission control module. It controls the reversing lights Rpm, and disables the starter when a transmission range is selected.torque, A defective signal results in "Reduceddriving throttle position, program". engine temperature. 6. Solenoid valves (SV) 3. Tiptronic control module Installationposition: On the hydrauliccontrol unit in the transmission. Installationposition: In the passenger compartment behind the right-hand The electronic transmission controls emergency seat recess. the transmissionfunctions via the SV's. SV's I, 2 and 3 are On-Offvalves. Their task is The Tiptronic control module is the information to switch over valves in the hydraulic system. and command centre of the entire system. From a large volume of incoming information The SV's(pressure regulators 1 ...4) are (measured variables),which are compared electronic pressure-controlvalves. They convert with stored driving and shifting programs, an electric current into a proportional hydraulic the Tiptronic control module selects pressure, and actuate the valves of the shifting the characteristic suitable for the type elements. of driving and sends commandsto the transmission to shift or not to shift. 37 01 DiagnosisjTroubleshooting, Tiptronic 37 -D 11 Printed in Germany -8, 1998 99637Dl