Ignition off
Storing engine-specific data:
- Engine type (4 or 6-cylinder engine)
- Maps (for delivery angle, pulse widths, impact time etc.), characteristic curves, constants
- Sensor correction and substitute values
- Engine protection functions and emergency programs
In case of a fault, storing the faults and indicating the fault location (circuit), fault type (short circuit, etc.).
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After ignition switched on
5 V voltage supply for boost pressure sensor electronics.
Monitoring and analyzing sensor values for start quantity control.
Constant monitoring of all connected circuits including circuit 15 and circuit 50 plausibility and starter series relay (for detecting faults).
Constantly monitoring and evaluating data from the control unit of drive control (FR), and transmitting a fault message (fault code) via the engine CAN bus in case of any fault.
Connection facility (interface) for STAR DIAGNOSIS to read out control unit version and data record version, measured values and fault codes.
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At engine start and when engine running
If immobilizer (WSP) programmed, actuating starter and unit pumps only if transponder code is correct.
Actuating the starter after a clearance from the control unit of drive control (FR) - without immobilizer (with transponder).
Setting and monitoring governed speed.
Controlling engine speed with various control characteristics (selection through the control unit of drive control (FR)).
Optimized control of delivery angle and start of delivery (start of injection) for each operating state of engine.
Smooth running control for compensating for delivery tolerances of unit pumps.
Actuation of the electromagnetic fan clutch in line with cooling capacity demand (dependent on coolant temperature).
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Additional active service and diagnostic functions
Starter actuation without injection (cranking engine).
Engine speed signal output to diagnostic socket for emission test.
Actuation and measuring functions for troubleshooting with STAR DIAGNOSIS:
- Selective cylinder shutoff
- Compression pressure measurement
- Charge pressure measurement
- Voltage indication
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The basic control unit (hardware without data records, performance maps) can be used for all MR/PLD engines offered.
The MR/PLD control unit is adapted to the corresponding engine variants (number of cylinders, firing order) only when the data records are loaded.
In some cases, the power output stages of the engine types are also determined by the data in the MR/PLD control unit.
A programmed control unit is a specially adapted engine component.
For this reason, reconditioned engines are always supplied complete with the engine wiring harness and the corresponding MR/PLD control unit.