View of engine compartment from rear right |
N3/33 | CDI control unit |
S07.08-4510-06
Location
The CDI control unit is located under the engine compartment fuse and relay module (K40/10).
Tasks
The CDI control unit performs the following tasks:
Controlling the engine basic functions
Reading in of signals
Evaluation of input factors
Output of signals and actuation of components
The CDI control unit operates in an electrical network of sensors and actuators to form the engine management system for engine 651.9. The CDI control unit also acts as the interface (gateway) between the three connected CAN bus systems.
Controlling the engine basic functions
Fuel supply
Glow system
Injection quantity control
Electronic accelerator
Diagnosis and fault storage
Drive authorization system and immobilizer
Thermal management
Exhaust gas recirculation
Exhaust treatment
Torque coordination
Engine management Start-Stop function
Reading in of signals
Input factors are read in over the following connections:
Direct line
Chassis CAN (CAN E)
Drivetrain-LIN (LIN C3)
Drive train CAN (CAN C)
Drive train sensor CAN (CAN I)
Evaluation of input factors
The input factors that have been read in are evaluated by the integrated microprocessor and the affected components are then actuated.
Output of signals and actuation of components
Initial parameter are output over the following connections:
Direct line
Chassis CAN
Drivetrain LIN
Drive train CAN
Drive train sensor CAN
MODEL 447.8
The Gateway for user interface CAN (N934) is the central interface (Gateway) for exchanging the function-relevant data from the control units that are connected to the various CAN bus systems.
Input parameters and initial parameters for the following components are read in or output over direct lines by the CDI control unit and are required by the engine management system:
Input factors over a direct line | Initial parameters over a direct line | Supplemental information |
Terminal 15 | – | – |
Circuit 30 (fused) | – | – |
Circuit 31 | – | – |
Terminal 87 | – | – |
Hot film mass air flow sensor (B2/12) | – | – |
Intake air temperature sensor (B2/12b1) | – | – |
Rail pressure sensor (B4/14) | – | Fuel high-pressure circuit |
Boost pressure sensor (B5/6) | – | – |
Low-pressure turbocharger boost pressure sensor (B5/9) | – | – |
Camshaft Hall sensor (B6/23) | – | – |
Coolant temperature sensor (B11/17) | – | – |
Temperature sensor upstream of SCR catalytic converter (B16/12) | – | With code MB6 (Low-pollutant vehicle Euro 6 Gr. I)) or with code MA6 (Low-pollutant vehicle Euro 6 Gr. III)) |
Exhaust manifold analog temperature sensor (B16/13) | – | – |
Temperature sensor downstream of charge air cooler (B17/13) | – | – |
Temperature sensor upstream of catalytic converter (B19/7) | – | Except code MF4 (Low-pollutant vehicle Euro 4 Gr. III)) |
Temperature sensor upstream of diesel particulate filter (B19/17) | – | Except code MF4 (Low-pollutant vehicle Euro 4 Gr. III)) |
Intake manifold pressure sensor (B28/17) | – | – |
Diesel particulate filter differential pressure sensor (B28/12) | – | Except code MF4 (Low-pollutant vehicle Euro 4 Gr. III)) |
Accelerator pedal module (B37/4) | – | – |
Engine oil level sensor (B40/6) | – | – |
Engine oil temperature sensor (B40/9) | – | – |
Fuel temperature sensor (B50/5) | – | – |
Exhaust pressure sensor (B60/3) | – | – |
Transmission neutral position sensor (B79/2) | – | With code GE1 (6-speed manual transmission TSG 380) |
Oxygen sensor (B85/4) | Oxygen sensor (B85/4) | – |
– | Circuit 50 starter relay (K40/10kM) | – |
Circuit 87M relay (K40/10kN) | Circuit 87M relay (K40/10kN) | – |
Circuit 15 relay (K40/10kR) | – | – |
Crankshaft position sensor (L5/11) | – | – |
Throttle valve actuator (M16/45) | Throttle valve actuator (M16/45) | – |
– | Intake port shutoff positioner (M72/1) | – |
Supplemental restraint system control unit (SRS) (N2/18), | – | – |
– | Fuel system control unit (FSCU) (N118) | – |
– | Vent line heater element (R39/7) | – |
– | Thermostat heating element (R48/2) | – |
Clutch pedal switch (S40/3) | – | With code GE1 (6-speed manual transmission TSG 380) |
Clutch pedal switch (S40/6) | – | With code GE1 (6-speed manual transmission TSG 380) |
– | Coolant pump switchover valve (Y19/10) | – |
– | Exhaust gas recirculation positioner (Y27/15) | – |
– | Exhaust gas recirculation cooling solenoid valve (Y27/16) | – |
– | Pressure regulating valve (Y74/5) | – |
– | Cylinder 1 injector (Y76/9) | – |
– | Cylinder 2 injector (Y76/10) | – |
– | Cylinder 3 injector (Y76/11) | – |
– | Cylinder 4 injector (Y76/12) | – |
– | Wastegate pressure transducer (Y77/7) | – |
– | Boost pressure control flap pressure transducer (Y93/1) | – |
– | Quantity control valve (Y94/3) | – |
– | Oil spray nozzle valve (Y127/1) | – |
– | Regulated oil pressure pump valve (Y133) | – |
Input parameters and initial parameters for the following components and control units are transmitted or received by the CDI control unit via the LIN or CAN and are needed by the engine management system:
Input factors over drivetrain-LIN (LIN C3) | Initial parameters over drivetrain-LIN (LIN C3) | Supplemental information |
Alternator (G2) | Alternator (G2) | – |
Electric fan (M91) | Electric fan (M91) | – |
Glow output stage (N14/8) | Glow output stage (N14/8) | – |
Input factors via the drive train CAN (CAN C) | Initial parameter via the drive train CAN (CAN C) | Supplemental information |
Fully integrated transmission control unit (VGS) (N15/11n4): | Fully integrated transmission control unit (VGS) (N15/11n4): | With code G42 (7G-TRONIC PLUS) |
Fuel system control unit (FSCU) (N118) | Fuel system control unit (FSCU) (N118) | – |
Input factors via chassis CAN (CAN E), model 447.6, 447.7 | Initial parameters via chassis CAN (CAN E) model 447.6, 447.7 | Additional information for model 447.6, 447.7 |
Instrument cluster (IC) control unit (A1/1) | Instrument cluster (IC) control unit (A1/1) | – |
Supplemental restraint system control unit (SRS) (N2/18), | – | – |
Signal acquisition and actuation module (SAM) control unit (N10/1) | – | Via interior CAN (CAN B) and electronic ignition lock control unit (EZS) (N73) |
Electronic Stability Program control unit (ESP) (N30/4) | – | – |
Left front door control unit (N69/3) | – | Via interior CAN (CAN B) and electronic ignition lock control unit (EZS) (N73) |
Upper control panel control unit (UCP) (N72/1) | – | Via battery sensor LIN (LIN B15), signal acquisition and actuation module (SAM) control unit (N10/1), interior CAN (CAN B) and electronic ignition lock control unit (EZS) (N73) |
Electronic ignition lock (EIS) control unit (N73) | Electronic ignition lock (EIS) control unit (N73) | – |
Automatic air conditioning control and operating unit (KLA-V&KLA-H) (S98) (with code HH4 (THERMOTRONIC automatic air conditioning)) and (with code HH9 (Semi-automatic regulated A/C, TEMPMATIC)) | – | Via interior CAN (CAN B) and electronic ignition lock control unit (EZS) (N73) |
Diagnostic connector (X11) | Diagnostic connector (X11) | Via diagnostic CAN (CAN D) and electronic ignition lock control unit (EZS) (N73) |
Input factors via chassis CAN (CAN E) model 447.8 | Initial parameters via chassis CAN (CAN E) model 447.8 | Additional information for model 447.8 |
Instrument cluster (IC) control unit (A1/1) | Instrument cluster (IC) control unit (A1/1) | Over the user interface CAN (CAN HMI) and Gateway for user interface CAN (N93/4) |
Central operating unit (ZBE) control unit (ZBE) (A40) | – | Via telematics CAN (CAN A), radio (audio/COMAND) (N87/6), user interface CAN (CAN HMI) and Gateway for user interface CAN (N93/4) |
DISTRONIC (DTR) control unit (A89) (with code ET4 (DISTRONIC Plus adaptive cruise control)) | – | – |
Supplemental restraint system control unit (SRS) (N2/18), | – | – |
Signal acquisition and actuation module (SAM) control unit (N10/1) | – | Via interior CAN (CAN B) and electronic ignition lock control unit (EZS) (N73) |
Electronic Stability Program control unit (ESP) (N30/4) | – | – |
Left front door control unit (N69/3) | – | Via interior CAN (CAN B) and electronic ignition lock control unit (EZS) (N73) |
Electronic ignition lock (EIS) control unit (N73) | Electronic ignition lock (EIS) control unit (N73) | – |
Radio (Audio/COMAND) (N87/6) | – | Over the user interface CAN (CAN HMI) and Gateway for user interface CAN (N93/4) |
Gateway for user interface CAN (N93/4) | Gateway for user interface CAN (N93/4) | – |
Automatic air conditioning control unit (KLA) (N154) (with code HH4 (THERMOTRONIC automatic air conditioning)) and (with code HH9 (Semi-automatic regulated A/C, TEMPMATIC)) | – | Via interior CAN (CAN B) and electronic ignition lock control unit (EZS) (N73) |
Diagnostic connector (X11) | Diagnostic connector (X11) | Via diagnostic CAN (CAN D) and electronic ignition lock control unit (EZS) (N73) |
Input factors via drive train sensor CAN (CAN I) | Initial parameters via drive train sensor CAN (CAN I) | Supplemental information |
NOx sensor control unit upstream of SCR catalytic converter (A97/1) | NOx sensor control unit upstream of SCR catalytic converter (A97/1) | With code MB6 (Low-pollutant vehicle Euro 6 Gr. I)) or with code MA6 (Low-pollutant vehicle Euro 6 Gr. III)) |
NOx sensor control unit downstream of SCR catalytic converter (A97/2) | NOx sensor control unit downstream of SCR catalytic converter (A97/2) | With code MB6 (Low-pollutant vehicle Euro 6 Gr. I)) or with code MA6 (Low-pollutant vehicle Euro 6 Gr. III)) |
AdBlue® (SCR) control unit (N141) | AdBlue® (SCR) control unit (N141) | With code MB6 (Low-pollutant vehicle Euro 6 Gr. I)) or with code MA6 (Low-pollutant vehicle Euro 6 Gr. III)) |
Body
The housing of the CDI control unit is made of diecast aluminum and the cover is made of corrosion-proof sheet steel. The CDI control unit is water proof and dust proof.
The inside contains the 32-bit measuring and control electronics for the engine management.
The CDI control unit has an internal atmospheric pressure sensor.
Ground connection
The ground connection "circuit 31" is made over a number of ground lines to the front right ground point for lamp unit (W2).
No-load current shutoff
Information for partial function "no-load current shutoff" is documented in the function description "Engine OFF energy management function".
Power supply
The CDI control unit is supplied with power by "circuit 30 fused" and, with the ignition on, by "circuit 87". In the operating voltage range it has both short-circuit protection and reversed polarity protection.
Power is supplied through several engaged parallel pins connected in parallel to relieve the electrical connections.
Variants
The variants of the engine management, for exampled country and exhaust variants, are activated with XD over the variant coding.
Assembly operations
Ensure before unplugging the connector on the CDI control unit that the ignition is switched off and processor run-on has ended. This is to prevent damage to the CDI control unit and save errors in the control units linked to the CAN.