Shown: engine from the front |
N3/9 | CDI control unit |
P07.16-3734-06
Location
The CDI control unit is on the air filter housing.
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 operates in an electrical network of sensors and actuators to form the engine management system for engine 651 Hybrid. As the master control unit it also takes on a large part of the controlling of hybrid 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
Energy management and regenerative braking
Torque coordination
Automatic Start/Stop
Cooling system for high-voltage components
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)
Hybrid CAN (CAN L)
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
Hybrid CAN
The front SAM control unit with fuse and relay module (N10/1) 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 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 | – | – |
Cylinder 3+ 4 knock sensor (A16/1) | – | – |
Cylinder 1+ 2 knock sensor (A16/4) | – | – |
Oil temperature sensor (B1) | – | – |
Hot film MAF sensor (B2/5) | – | – |
Intake air temperature sensor (B2/5b1) | – | – |
Rail pressure sensor (B4/6) | – | Fuel high-pressure circuit |
Boost pressure sensor (B5/1) | – | – |
Low-pressure turbocharger boost pressure sensor (B5/4) | – | – |
Camshaft Hall sensor (B6/1) | – | – |
Coolant temperature sensor (B11/4) | – | – |
Charge air temperature sensor (B17/8) | – | – |
Temperature sensor upstream of diesel particulate filter (B19/9) | – | With code 474 (Diesel particulate filter) |
Temperature sensor upstream of turbocharger (B19/11) | – | – |
Pressure sensor downstream of air filter (B28/5) | – | – |
DPF differential pressure sensor (B28/8) | – | With code 474 (Diesel particulate filter) |
Accelerator pedal sensor (B37) | Accelerator pedal sensor (B37) | – |
Fuel temperature sensor (B50) | – | – |
Exhaust pressure sensor (B60) | – | – |
Crankshaft Hall sensor (B70) | – | – |
– | Starter circuit 50 relay (N10/1kJ) | – |
– | Engine circuit 87 relay (N10/1kJ) | – |
– | Circuit 15 relay (N10/1kJ) | – |
Oxygen sensor upstream of catalytic converter (G3/2) | Oxygen sensor upstream of catalytic converter (G3/2) | – |
Internal combustion engine fan motor and air conditioning with integrated control (M4/7) | Internal combustion engine fan motor and air conditioning with integrated control (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) | – |
– | Coolant thermostat heating element(R48) | – |
Oil level check switch (S43) | – | – |
– | Exhaust gas recirculation actuator (Y27/9) | – |
– | Boost pressure control pressure transducer (Y31/5) | – |
– | 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) | – |
– | Radiator shutters actuator (Y84) | – |
– | Exhaust gas recirculation cooler bypass switchover valve (Y85) | – |
– | Boost pressure control flap pressure transducer (Y93) | – |
– | Quantity control valve (Y94) | – |
– | Engine oil pump valve (Y130) | – |
– | Oil spray nozzle shutoff valve (Y131) | – |
– | Coolant pump switchover 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 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) | With code 427 (Automatic transmission 7-speed) |
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 front SAM control unit with fuse and relay module (N10/1) |
Supplemental Restraint System control unit (N2/10) | – | – |
Front SAM control unit with fuse and relay module (N10/1) | – | – |
Rear SAM control unit with fuse and relay module (N10/2) | – | Via interior CAN (CAN B) and the front SAM control unit with fuse and relay module (N10/1) |
AAC control and operating unit (N22/7) | – | Via interior CAN (CAN B) and the front SAM control unit with fuse and relay module (N10/1) |
Regenerative braking system control unit (N30/6) | – | – |
AIRmatic control unit (N51/3) | – | With CODE 489 (AIRmatic) air suspension with continuous adjustment damping |
Radar sensors control unit (N62/1) | – | With code 23P(Driving assistance package) via suspension-FlexRay (Flex E) and the chassis gateway control unit (N93/7) |
Electronic ignition lock control unit (N73) | Electronic ignition lock control unit (N73) | – |
Chassis gateway control unit (N93/7) | – | – |
Rear axle electronic level control control unit (N97) | – | Except CODE 489 (AIRmatic) air suspension with continuous adjustment damping |
Diagnostic connector (X11/4) | Diagnostic connector (X11/4) | Via diagnostic CAN (CAN D) and the front SAM control unit with fuse and relay module (N10/1) |
Input factors via hybrid CAN (CAN L) | Starting data via hybrid CAN (CAN L) | Supplemental information |
Battery management system control unit (N82/2) | Battery management system control unit (N82/2) | – |
Power electronics control unit (N129/1) | Power electronics control unit (N129/1) | – |
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 "circuit 31" ground connection is made via multiple ground lines to the right assembly compartment ground point (W16/6).
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.
Information about the partial function "no-load current switch off" 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 plug 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.