Component description for CDI control unit - GF07.16-P-6000OHG

ENGINES 642.940 in MODEL 164.120/122 as of model year 2009/YoM 08 model refinement package 

ENGINES 642.940 in MODEL 164.822 as of model year 2009/YoM 08 

ENGINES 642.950 in MODEL 251.020/022/026/122/126 as of model year 2009/YoM 08 

View of engine compartment from rear right 

Location 

The CDI control unit is built into the engine compartment at the right in front of the windshield.

Task 

The CDI control unit operates in an electrical network of sensors and actuators to form the engine timing system for engine 642.9.

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

• Fuel supply
• Glow system control
• Injection quantity control
• Diagnosis and fault storage
• Drive authorization system and immobilizer
• Heat management
• Torque interface
• Alternator interface
• Exhaust gas recirculation
• Emission control

The CDI control unit is fitted with an internal atmospheric pressure sensor.

Input and output signals 

The following input signals are evaluated by the engine timing 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 (fused)
• Circuit 31
• Circuit 87
• Oil temperature sensor (B1)
• Left hot film mass air flow sensor (B2/6)
• Intake air temperature sensor (B2/6b1)
• Right hot film mass air flow sensor (B2/7)
• Intake air temperature sensor (B2/7b1)
• Rail pressure sensor (B4/6)
• Charge pressure sensor (B5/1)
• Camshaft Hall sensor (B6/1)
• Coolant temperature sensor (B11/4)
• Charge air temperature sensor (B17/8)
• CAT temperature sensor (B19)
• Temperature sensor upstream of diesel particulate filter (B19/9) (with code (474) Particulate filter)
• Pressure sensor downstream of air filter (B28/5)
• Pressure differential sensor (DPF) (B28/8) (with code (474) Particulate filter)
• Accelerator pedal sensor (B37) - potentiometer 1
• Accelerator pedal sensor - potentiometer 2
• Fuel temperature sensor (B50)
• Exhaust back pressure sensor (B60)
• Crankshaft Hall sensor (B70)
• Fuel filter condensation sensor with heating element (B76/1) (with code (U41) Fuel/water separator and lubrication package) or with code (71o) Retrofitted heated fuel filter
• O2 sensor upstream of CAT (G3/2)
• Combustion engine and air conditioning fan motor with integrated control (M4/7), diagnostic data
• Oil level check switch (S43)

Direct output signals 

• O2 sensor upstream of CAT - oxygen sensor heater
• Throttle valve actuator (M16/6)
• Intake port shutoff motor (M55)
• Fuel pump relay (F4kO)
• Circuit 15 relay (F58kH)
• Starter relay (F58kI)
• Engine circuit 87 relay (F58kD)
• Vent line heater element (R39/1)
• Condensation sensor for fuel filter with heating element
• Combustion engine and air conditioning fan motor with integrated control - specified fan speed
• Accelerator pedal sensor - reference ground of potentiometers 1 and 2
• O2 sensor upstream of CAT - oxygen sensor heater
• Left exhaust gas recirculation controller (Y27/9)
• Pressure regulator valve (Y74)
• Cylinder 1 fuel injector (Y76y1)
• Cylinder 2 fuel injector (Y76y2)
• Cylinder 3 fuel injector (Y76y3)
• Cylinder 4 fuel injector (Y76y4)
• Cylinder 5 fuel injector (Y76y5)
• Cylinder 6 fuel injector (Y76y6)
• Boost pressure positioner (Y77/1)
• Quantity control valve (Y94)

LIN signals 

• Alternator interface via drive LIN (LIN C1)
• Alternator (G2)
• Glow time output stage (N14/3), control of various flow functions and transmission of system faults

CAN input signals 

Instrument cluster (A1) 

• Fuel reserve signal

Restraint systems control unit (N2/7) 

• Crash signal

AAC [KLA] control and operating unit (N22) (except code (581) Comfort automatic air conditioning) or comfort AAC control and operating unit (N22/7) (with code (581) Comfort automatic air conditioning) 

• Specified fan speed request
• Air conditioning, status

EZS control unit (N73) 

• Start enable (drive authorization system)

ESP control unit (N47/5) 

• Vehicle speed
• Wheel speed signal
• Brake recognition
• Cruise control request
• Engine torque request

Electric controller unit (VGS) (Y3/8) 

• 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
• Transmission limp-home mode

CAN output signals 

Instrument cluster 

• Engine oil level too low
• Circuit 61 signal (generated by the CDI control unit)
• 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))

EZS control unit 

• Start enable request (drive authorization system)

Electric controller unit (VGS) 

• Requests for catalytic converter heating
• Shift request
• Engine torque
• Engine coolant temperature
• Engine oil temperature
• Engine speed
• Engine load
• Kickdown
• Engine speed limitation active
• Engine timing limp-home mode

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 timing.

Power supply 

The CDI control unit is "circuit 30 fused" and also supplied with voltage 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 pins connected in parallel to relieve the electrical connectors.

Ground connection 

The ground connection "circuit 31" is made via a number of ground lines to the right major assemblies compartment ground, power ground (W16/4).

Processor run-on 

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 (for example, on-board diagnosis (OBD), drive authorization system (DAS), thermal management).

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 timing variants, such as country and exhaust gas variants, are activated with the Diagnosis Assistance System (DAS) using the variant coding function.

Replacement of the CDI control unit is not necessary.

	Wiring diagram for common rail diesel injection (CDI) control unit	N3/9	Vehicle connector (Specification 1) model 164.1/8	PE07.16-P-2101-97MAA
		N3/9	Vehicle connector (Specification 1) model 251. 0/1	PE07.16-P-2101-97RAA
	Wiring diagram for common rail diesel injection (CDI) control unit	N3/9	Engine connector (Specification 2) model 164.1/8	PE07.16-P-2101-97MAB
		N3/9	Engine connector (Specification 2) model 251. 0/1	PE07.16-P-2101-97RAB