Releasing chain tensioner • Unscrew left-hand end cover • Release M6 screw at chain tensioner in order to reduce the oil pressure in the chain tensioner • Turn the engine a little in counterclockwise direction in order to tension the chain • Alternatively, tension the chain with the aid of the camshaft • Fix chain… Read More »
Setting ignition TDC at cylinder No. 1 We recommend the following procedure in order to check the valve timing in assembled status, i.e. with the cylinder head mounted in position: • Remove camshaft sensor • Turn camshaft until sensor cam approximately faces upward • The crankshaft is now located just before the blocking position •… Read More »
Engine smooth running control procedure The signal from the crankshaft position/rpm sensor is used to evaluate the rotation of the crankshaft on completion of each combustion cycle. Smooth running control corrects the speed differences of the individual cylinders caused by differences in the injection quantities and the cylinder efficiency. This is accomplished by rapid addition… Read More »
General The control unit electronics run a self-test commencing as soon as terminal 15 is activated; thereafter, system monitoring is continuous. Errors are stored in the non-volatile error memory. The operating parameters and the fault memory contents are read by the tester via the diagnosis interface. Furthermore, in this way, it is possible to check… Read More »
Their programming prepares the DDE control units 4.0 and 4.1 for operation in the engines of different vehicles. It is this programming which produces the different torque and power curves. To ensure a DDE control unit is not programmed with an incorrect data set, the programming procedure includes a check of the model version/control unit… Read More »
The DDE control unit automatically performs several self-tests to ensure reliable operation. In addition to the self-test at terminal 15 “ON” and constant background checks, safety-relevant functions are also monitored. Monitoring includes: • Main-relay activation • Evaluation of the terminal 15 signal • Monitoring of the microcontroller in coasting mode • Test of the EAB… Read More »
Activation and deactivation of the air-conditioning compressor depends on a number of vehicle and control-unit states. When high torque is needed for brief period (pulling away from rest, accelerating) the air-conditioning compressor control logic shuts down the air-conditioning compressor to ensure that sufficient engine torque is available. Activation comprises two subfunctions: • Air-conditioning compressor logic… Read More »
The electric fuel pump (EKP) and the rail pressure control valve (DRV) are similar in terms of activation. Both can be energised for only a certain period of time (depends on coolant temperature: characteristic curve) in order to avoid thermal damage due to deficient cooling or useless pumping (EKP) against an inactive high pressure pump… Read More »
Electric engine fan control calculates the setpoint speed for the electric fan. The engine-fan setpoint speed is derived from a characteristic curve as a function of: • Water temperature • Current road speed The fan output stage requested by the air-conditioning control unit via the CAN bus is also taken into account as a variable.… Read More »
Boost pressure control has the task of controlling the turbocharger with variable turbine geometry (VNT). Boost pressure control comprises: • Driving-style classification • Setpoint calculation • Boost-pressure control Driving-style classification This is the function which allows the control characteristic map and the boost-pressure setpoint characteristic map to be selected on the basis of the style… Read More »