Component Description For CDI Control Unit - GF07.16-S-6000SA

ENGINES 642.8 in MODEL 906 

with CODE (MG5) Engine OM 642 DE 30 LA, 140 kW (190 hp) 3800 RPM 

except CODE (ZU7) National version for Canada 

except CODE (ZU8) National version for USA 

ENGINES 642.8 in MODEL 639 

with CODE (XZ1) Model generation 1 

with CODE (MZ0) BlueEFFICIENCY 

Illustrated on model 906 

Location 

The CDI control unit is located in the front left 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 642.8. 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
• engine timing start-stop function (for code (MJ7) ECO start/ stop function (for model 639) or for code (MJ7) ECO Start (for model 906))
• drive authorization system and immobilizer
• thermal management
• torque interface
• alternator interface
• exhaust gas recirculation
• exhaust gas cleaning

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 
• LIN signals 
• CAN input signals 
• CAN output signals 

Direct input signals 

• circuit 15
• circuit 30
• circuit 87
• hot film mass air flow sensor (B2/14)
• rail pressure sensor (B4/17)
• boost pressure sensor (B5/8)
• camshaft sensor (B6/24)
• coolant temperature sensor (B11/19)
• temperature sensor upstream of turbocharger (B16/11)
• charge air temperature sensor (B17/15)
• temperature sensor upstream of diesel particulate filter (B19/19)
• exhaust gas recirculation cooler temperature sensor (B19/21) (for model 639)
• intake manifold pressure sensor (B28/19)
• diesel particulate filter differential pressure sensor (B28/20)
• accelerator pedal module (B37/4) (for model 639) or accelerator pedal module (B37/3) (for model 906)
• engine oil sensor (B40/8)
• fuel temperature sensor (B50/6)
• exhaust back pressure sensor (B60/4)
• crankshaft sensor (B70/1)
• fuel filter heater with water level sensor (R53/1)
• oxygen sensor (B85/3)

Direct output signals 

• fuel filter heater with water level sensor
• oxygen sensor
• circuit 15 relay (K40/9k8)
• engine circuit 87 relay (K40/9k4) (for model 639) or engine timing circuit 87 relay (K40/9k7) (for model 906)
• throttle valve actuator (M16/48)
• intake port shutoff positioner (M72/2) (for model 639)
• electronic regulated fuel pump (N118) (for model 639) or FSCU (N118/5) (for model 906)
• vent line heater element (R39/4)
• exhaust gas recirculation cooling switchover valve without SRA (Y27/2) (for model 639)
• exhaust gas recirculation cooling switchover valve with SRA (Y27/3) (for model 639)
• exhaust gas recirculation cooling switchover valve (Y27/13) (for model 906)
• exhaust gas recirculation positioner (Y27/17)
• pressure regulator valve (Y74/6)
• cylinder 1 injector (Y76/18)
• cylinder 2 injector (Y76/19)
• cylinder 3 injector (Y76/20)
• cylinder 4 injector (Y76/21)
• cylinder 5 injector (Y76/22)
• cylinder 6 injector (Y76/23)
• boost pressure actuator (Y77/8)
• quantity control valve (Y94/4)

LIN signals 

• alternator interface via drivetrain LIN (LIN C1)
• alternator (G2/6) (for model 639) or alternator with LIN bus (G2/7) (for model 906)
• glow output stage (N14/7), to control various glow functions and send system errors

CAN input signals 

Instrument cluster (A1) 

• fuel reserve signal

Lowline airbag control unit (N2/14) 

• 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

• 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)

ESM [EWM] control unit (N15/5) 

• selector lever module position

ESP control unit (N30/4) 

• vehicle speed
• wheel speed signal
• brake recognition
• cruise control request
• engine torque request

EZS control unit (N73) 

• start enable (drive authorization system)

Electronically regulated fuel pump (for model 639) 

• self-diagnosis data
• requested diagnostic data

CAN output signals 

Instrument cluster 

• Fuel consumption (the trip computer is informed about the current fuel consumption by means of square-wave pulse packages (1 pulse = 0.2 l/h))
• circuit 61 signal (generated by CDI control unit)
• actuation of EOBD indicator lamp

EZS control unit 

• start enable request (drive authorization system)

Electronically regulated fuel pump (for model 639) or FSCU (for model 906) 

• diagnosis request

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

Design 

The housing of the CDI control unit is made of die-cast aluminum and the cover is made of corrosion-proof sheet steel. The CDI control unit is water proof and dust proof.

The housing contains the 32-bit measuring and control electronics for the engine control.

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 pins connected in parallel to relieve the electrical connectors.

Ground connection 

The ground connection "terminal 31" takes place over a number of ground lines to the lamp unit ground point at the front right (W2) (for a left-hand drive vehicle) or the lamp unit ground point at the front left (W9) (for RHD in model 639) or lamp unit ground point at the front left (W9/6) (for model 906).

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.

Variants 

The engine control variants (e.g. national and exhaust variants) are activated with Xentry Diagnostics using the variant coding function. Replacement of the CDI control unit is not necessary.