Component description for CDI control unit

D07.08-1118-08

Illustrated on model 906

N3/28 CDI control unit

Location

The CDI control unit is located in the front right of the engine compartment.

Task

The CDI control unit operates in an electrical network of sensors and actuators to form the engine control system for engine 651.

The following systems and functions are controlled and coordinated by the CDI control unit according to input signals:

- fuel supply

- glow system control

- injected quantity control

- diagnosis and fault storage

- drive authorization system and immobilizer

- thermal management

- torque interface

- alternator interface

- exhaust gas recirculation (EGR)

- exhaust gas cleaning

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 The CDI control unit has an internal atmospheric pressure sensor.

Input and output signals

The following input signals are evaluated by the engine control system and respective output signals are issued:

 Direct input signals

 Direct output signals

 Local Interconnect Network (LIN) signals

 Control Area Network (CAN) input signals

 CAN output signals

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Direct input signals

- circuit 15

- circuit 30

- circuit 31

- circuit 87

- knock sensor 1 (A16/5)

- knock sensor 2 (A16/6)

- hot film mass air flow sensor (B2/12)

- intake air temperature sensor (B2/12b1) (for model 906) or intake air temperature sensor (B2/8b1) (for model 639)

- rail pressure sensor (B4/16)

- boost pressure sensor (B5/6)

- camshaft sensor (B6/23)

- coolant temperature sensor (B11/17)

- charge air temperature sensor (B17/13)

- temperature sensor upstream of diesel particulate filter (B19/17)

- temperature sensor upstream of turbocharger (B16/13)

- intake manifold pressure sensor (B28/17)

- diesel particulate filter differential pressure sensor (B28/18)

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- accelerator pedal module (B37/3) (for model 906) or accelerator pedal module (B37/4) (for model 639)

- fuel temperature sensor (B50/5)

- exhaust back pressure sensor (B60/3)

- fuel filter heater with water level sensor (R53)

- oxygen sensor (B85/2)

- crankshaft sensor (L5/10)

- engine oil level sensor (B40/6)

- engine oil temperature sensor (B40/9)

- crash signal, from the lowline airbag control unit (N2/14) , except code (SH6) Thoraxbag for driver (in the backrest) (for model 906), except code (SH7) Thoraxbag for driver and front passenger (in backrest) or except code (SH9) Windowbag for driver and front passenger or with highline airbag control unit (N2/15) (for model 906), with code (SH6) Thoraxbag for driver (in the backrest) (for model 906), with code (SH7) Thoraxbag for driver and front passenger (in backrest), with code (SH9) Windowbag for driver and front passenger

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Direct output signals

- throttle valve actuator (M16/45)

- fuel pump relay (K40/9k3) (for model 906) or fuel pump relay (K40/9k6) (for model 639)

- circuit 50 starter relay (K40/9k5)

- engine timing circuit 87 relay (K40/9k7) (for model 906) or engine circuit 87 relay (K40/9k4) (for model 639)

- vent line heater element (R39/3)

- thermostat heating element (R48/2)

- accelerator pedal module

- exhaust gas recirculation positioner (Y27/15)

- pressure regulator valve (Y74/5)

- cylinder 1 injector (Y76/14)

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- cylinder 2 injector (Y76/15)

- cylinder 3 injector (Y76/16)

- cylinder 4 injector (Y76/17)

- boost pressure actuator (Y77/6)

- exhaust gas recirculation cooling solenoid valve (Y27/16)

- quantity control valve (Y94/3)

- valve regulated oil pressure pump (Y133) (for model 639)

LIN signals

- alternator with LIN bus (G2/7) (for model 906), communication

- glow output stage (N14/5), communication

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CAN input signals

Instrument cluster (A1)

- fuel reserve signal

AB Lowliner control unit (for model 906), except code (SH6) Thoraxbag for driver (in the backrest), except code (SH7) Thoraxbag for driver and front passenger (in the backrest), except code (SH9) Windowbag for driver and front passenger or AB Lowliner control unit, with code (SH6) Thoraxbag for driver (in the backrest) (for model 906), with code (SH7) Thoraxbag for driver and front passenger (in the backrest), with code (SH9) Windowbag for driver and front passenger

- crash signal

EGS control unit (N15/3) (with transmission 722.6) or control unit (Y3/8n4) (with transmission 722.9)

- drive position

- transmission mode

- actual gear, target gear

Engine torque reduction request

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- starter enable in selector lever position "P", "N"

- engine idle specified speed for actuation of the torque converter lockup clutch

- status of torque converter lockup clutch

- limp-home mode EGS or fully integrated transmission control (VGS)

KLA control and operating unit (S98), with code (HH9) Regulated air conditioning (Tempmatic)

- request for fan specified speed for A/C 1 additional fan (M4/13) (for model 906) or A/C additional fan (M4) (for model 639) and A/C 2 additional fan (M4/14) (for model 906) or A/C additional fan (M4/2) (for model 639)

- A/C, status

EZS control unit (N73)

- start enable by drive authorization system level 3 (FBS 3)

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ESP control unit (N30/4)

- vehicle speed

- wheel speed signal

- brake recognition

- cruise control request, with code (MS1) CC

- engine torque request

PSM control unit (N26/15) (with code (ED5) Parameterizable special module (PSM) or code (ED8) Preinstallation for a parameterizable special module (PSM)(for model 906))

- Working speed control, adaptation of the engine rpm

CAN output signals

Instrument cluster

- messages in display (A1p1) (for model 906)

- circuit 61 signal

ESM [EWM] control unit (N15/5)

- selector lever module position

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EGS control unit (with transmission 722.6) or control unit (with transmission 722.9)

- requests for shift line displacement for CAT heating

Switching request

- engine torque

- engine coolant temperature

- engine speed

- engine load

- kickdown

- engine speed limitation active

- limp-home mode engine control

EZS control unit

- query regarding start enable by the FBS 3

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PSM control unit () (with code (ED5) Parameterizable special module (PSM) or code (ED8) Preinstallation for a parameterizable special module (PSM)(for model 906))

- Working speed control, feedback

 If the CDI control unit receives the signal "circuit 15 OFF" a processor run-on of approx. 4 seconds is started. However, it may also last for several minutes due to various functions (such as OBD, FBS 3).