Engine Control Module: Description and Operation

GF07.16-P-6000RT Component Description For The CDI Control Unit
- up to model year 08

Component Identification:

Location
The CDI control unit is installed on the left in direction of travel in front wheelhouse between fender and sidewall.

Task
The CDI control unit controls the following systems depending on the information received:
^ Fuel supply
^ Control of the glow system at engine start and during driving mode
^ Injection quantity control at engine start and during driving mode
^ Emission control system
^ Boost pressure control
^ Shutoff of the refrigerant compressor (A9)
^ Shut-off control

The CDI control unit reads the signals from the following components:
^ Oil temperature sensor (B1)
^ Left hot film mass air flow sensor (B2/6)
^ Intake air temperature sensor (B2/6b1)
^ Right hot film mass air flow sensor (B2/7)
^ Intake air temperature sensor (B2/7b1)
^ Rail pressure sensor (B4/6)
^ Charge pressure sensor (B5/1)
^ Camshaft Hall sensor (B6/1)
^ Coolant temperature sensor (B11/4)
^ Charge air temperature sensor (B17/8)
^ TWC temperature sensor (B19)
^ Temperature sensor upstream diesel particles (B19/9) on models with code (474) particulate filter
^ Pressure sensor downstream of air filter (B28/5)
^ Differential pressure sensor (DPF) (B28/8) on models with code (474) particulate filter
^ Accelerator pedal sensor (B37)
^ Fuel temperature sensor (B50)
^ Exhaust back pressure sensor (B60)
^ Crankshaft Hall sensor (B70)
^ O2 sensor upstream of TWC (G3/2)
^ Oil level indicator switch (S43)
^ Fuel filter water level sensor (B76) for vehicles with code (494) USA version

Within the CDI control unit there is an atmospheric pressure sensor for altitude adjustment.
The CDI control unit actuates the following components:
^ O2 sensor heater upstream of TWC
^ Throttle valve actuator (M16/6)
^ Intake port shutoff motor(M55)
^ Starter relay (F58kI)
^ Fuel pump relay (F4kO)
^ Vent line heater element (R39/1)
^ Left exhaust gas recirculation positioner (Y27/9)
^ Pressure regulator valve (Y74)
^ Charge pressure positioner (Y77/1)
^ Cylinder 1 fuel injector (Y76y1)
^ Cylinder 2 fuel injector (Y76y2)
^ Cylinder 3 fuel injector (Y76y3)
^ Cylinder 4 fuel injector (Y76y4)
^ Fuel injector cylinder 5 (Y76y5)
^ ^ Fuel injector cylinder 6 (Y76y6)
^ Quantity control valve (Y94)

Communication via the Local Interconnect Network (LIN) takes place via the following components:
^ Alternator (G2)
^ Glow time output stage (N14/3), control of various flow functions and transmission of system faults

The CDI control unit communicates with the following components via the Controller Area Network bus Class C (engine compartment) (CAN C):
^ Instrument cluster (A1), emission of error messages via the multifunction display (A1p13)
^ Instrument cluster, actuation of engine diagnosis indicator lamp (A1e58) or actuation of CHECK ENGINE indicator lamp (A1e26) for vehicles with code (494) USA version
^ ESP control unit (N47-5)
^ EIS [EZS] control unit (N73)
^ Steering column module (N80), cruise control via the CC [TPM] switch (S40/4)
^ Central gateway control unit (N93)
^ Fully integrated transmission control (VGS) control unit (Y3/8n4), with transmission 722.9

The CDI control unit has a fault memory, which can be output via STAR DIAGNOSIS.