View of the engine from above |
N3/9 | CDI control unit |
P07.16-4049-76
Location
The CDI control unit is located on the center of the engine.
Task
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 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
Start/stop function
Reading in of signals
Input factors are read in over the following connections:
Direct line
Drive-LIN (LIN C1)
Drive train CAN (CAN C)
Chassis CAN 1 (CAN E1)
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
Drive train LIN
Drive train CAN
Chassis CAN 1
Drive train sensor CAN
The electronic ignition lock control unit (N73) is the central interface (Gateway) for exchange of function-relevant data for control units which are connected to the various Control Area Network (CAN) bus systems.
Input factors and initial parameters for the following components are read in or output over direct lines by the CDI control unit and are needed by the engine management:
Input factors over a direct line | Initial parameters over a direct line | Supplemental information |
Terminal 15 | – | – |
Circuit 30 (fused) | – | – |
Circuit 31 | – | – |
Circuit 87M4 | – | – |
Engine oil temperature sensor (B1) | – | – |
Left hot film mass air flow sensor (B2/6) | – | – |
Left intake air temperature sensor (B2/6b1) | – | – |
Right hot film mass air flow sensor (B2/7) | – | – |
Right intake air temperature sensor (B2/7b1) | – | – |
– high pressure fuel pressure sensor (B4/6) | – | Fuel high-pressure circuit |
Boost pressure sensor (B5/1) | – | – |
Camshaft Hall sensor (B6/1) | – | – |
Coolant temperature sensor (B11/4) | – | – |
Exhaust gas recirculation temperature sensor (B16/14) | – | With CODE U77 (BLUETEC (SCR) diesel exhaust treatment) and CODE 494 (USA version) |
Temperature sensor upstream of SCR catalytic converter (B16/15) | – | With CODE U77 (BLUETEC (SCR) diesel exhaust treatment) |
Charge air temperature sensor (B17/8) | – | – |
Temperature sensor upstream of catalytic converter (B19/7) | – | With CODE U77 (BLUETEC (SCR) diesel exhaust treatment) |
Temperature sensor upstream of diesel particulate filter (B19/9) | – | – |
Temperature sensor upstream of ATL (B19/11) | – | – |
DPF differential pressure sensor (B28/8) | – | – |
Pressure sensor downstream of air filter (B28/11) | – | – |
Accelerator pedal sensor (B37) | – | – |
Fuel temperature sensor (B50) | – | – |
Exhaust pressure sensor (B60) | – | – |
Crankshaft Hall sensor (B70) | – | – |
Exhaust gas recirculation cooling bypass flap Hall sensor (B90) | – | With CODE 494 (USA version) |
Left intake port shutoff Hall sensor (B96/1) | – | With CODE 494 (USA version) |
Right intake port shutoff Hall sensor (B96/2) | – | With CODE 494 (USA version) |
– | Starter circuit 50 relay (F58kM) | – |
Circuit relay87M (F58kN) | Circuit relay87M (F58kN) | – |
Circuit 15 relay (F58kR) | – | – |
Oxygen sensor upstream of catalytic converter (G3/2) | Oxygen sensor upstream of catalytic converter (G3/2) | – |
Fan motor (M4/7) | Fan motor (M4/7) | – |
Throttle valve actuator (M16/6) | Throttle valve actuator (M16/6) | – |
– | Intake port shutoff actuator motor (M55) | – |
Supplemental Restraint System control unit (N2/10) | – | – |
– | Fuel system control unit (N118) | – |
– | Vent line heater element (R39/1) | – |
Oil level check switch (S43) | – | – |
Exhaust gas recirculation actuator (Y27/9) | Exhaust gas recirculation actuator (Y27/9) | – |
– | Pressure regulating valve (Y74) | – |
– | Cylinder 1 fuel injector (Y76/1) | – |
– | Cylinder 2 fuel injector (Y76/2) | – |
– | Cylinder 3 fuel injector (Y76/3) | – |
– | Cylinder 4 fuel injector (Y76/4) | – |
– | Cylinder 5 fuel injector (Y76/5) | – |
– | Cylinder 6 fuel injector (Y76/6) | – |
– | Boost pressure control pressure transducer (Y77/1) | – |
– | Exhaust gas recirculation cooler bypass switchover valve (Y85) | – |
– | Quantity control valve (Y94) | – |
– | Left switchable engine mount (Y123) and right switchable engine mount (Y123/1) | – |
– | Coolant pump switchover valve (Y133) | – |
Input 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 via the drive-LIN (LIN C1) | Initial parameters via the drive-LIN (LIN C1) | Supplemental information |
Alternator (G2) | Alternator (G2) | – |
Glow output stage (N14/3) | Glow output stage (N14/3) | – |
Input factors via the drive train CAN (CAN C) | Initial parameter via the drive train CAN (CAN C) | Supplemental information |
Fuel system control unit (N118) | Fuel system control unit (N118) | – |
Fully integrated transmission control unit (Y3/8n4) | Fully integrated transmission control unit (Y3/8n4) | – |
Input factors via chassis CAN 1 (CAN E1) | Initial parameters via chassis CAN 1 (CAN E1) | Supplemental information |
Instrument cluster (A1) | Instrument cluster (A1) | Via chassis CAN 2 (CAN E2) and the electronic ignition lock control unit (N73) |
Supplemental Restraint System control unit (N2/10) | – | – |
SAM control unit (N10) | – | Via interior CAN (CAN B) and the electronic ignition lock control unit (N73) |
AAC control and operating unit (N22/7) | – | Via interior CAN (CAN B) and the electronic ignition lock control unit (N73) |
Electronic Stability Program control unit (N30/4) | – | – |
AIRmatic control unit (N51/3) | – | With code 489 (AIRMATIC) |
Radar sensors control unit (N62/1) | – | Via the chassis FlexRay (Flex E) and the chassis gateway control unit (N93/7) with code 23P (Driver Assistance Package Plus) |
Left front door control unit (N69/1) | – | Via interior CAN (CAN B) and the electronic ignition lock control unit (N73) |
Upper control panel control unit (N72/1) | – | Over the battery sensor LINE (LINE B15) to the SAM control unit and over the interior CAN (CAN B) and electronic ignition lock control unit (N73) |
Electronic ignition lock control unit (N73) | Electronic ignition lock control unit (N73) | – |
Steering column tube module control unit (N80) | – | – |
Diagnostic connector (X11/4) | Diagnostic connector (X11/4) | via diagnostic CAN (CAN D) and the electronic ignition lock control unit (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 downstream of diesel particulate filter (N37/7) | NOx sensor control unit downstream of diesel particulate filter (N37/7) | With CODE U77 (BLUETEC (SCR) diesel exhaust treatment) |
NOx sensor control unit downstream of SCR catalytic converter (N37/8) | NOx sensor control unit downstream of SCR catalytic converter (N37/8) | With CODE U77 (BLUETEC (SCR) diesel exhaust treatment) |
AdBlue® control unit (N118/5) | AdBlue® control unit (N118/5) | With CODE U77 (BLUETEC (SCR) diesel exhaust treatment) |
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 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).
Power supply
The CDI control unit is supplied with power by "circuit 30 fused" and also, for 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.
Information for partial function "no-load current shutoff" is documented in the function description "Engine OFF energy management function".
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.