LH Control Unit

The LH control unit is located in module box in right rear corner of engine compartment. See Figure . LH control unit connector is color-coded Dark Green/Light Green. The LH control unit receives engine operating information from sensors and controls fuel injection.

The LH control unit has a self-adaptation feature for emission control system. As engine wears, deviations can occur such as wear in fuel injectors or intake air leaks. During the self-adaptation process, correction factors are continuously calculated and permanently stored.

After repairing fuel injection system, the LH control unit will again adapt during engine operation. Trail installation of LH control units from other vehicles is possible only if the LH control units self-adaptation feature is reset to its mean value. Refer to the TESTS W/CODES article in this section for self-adaptation reset procedure.

Fig 1: LH-SFI System Block Diagram

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 2: Cruise Control/Idle Speed Control Block Diagram (3.2L)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 3: Electronic Accelerator Block Diagram (3.2L)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.