Operation CHARM: Car repair manuals for everyone.

GF07.16-P-6000OGU Component Description For CDI Control Unit




GF07.16-P-6000OGU Component Description For CDI Control Unit
ENGINES 642.820 in MODEL 164.124
- as of model year 2009
/ YoM 08 model refinement package
ENGINES 642.820 in MODEL 164.121 /125
ENGINES 642.820 in MODEL 164.824
- as of model year 2009
/ YoM 08
ENGINES 642.820 in MODEL 164.825
ENGINES 642.870 in MODEL 251.124 /125
- as of model year 2009
/ YoM 08
ENGINES 642.872 in MODEL 251.021 /023 /123
- as of model year 2011
/YoM 10 facelift





View of engine compartment from rear right

N3/9 CDI control unit

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 642.8. 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)
- Exhaust gas recirculation temperature sensor (B16/14)
- Temperature sensor upstream of SCR catalytic converter (B16/15) (with code (U42) BlueTEC (SCR) diesel exhaust treatment)
- Charge air temperature sensor (B17/8)
- Temperature sensor upstream of CAT (B19/7) (for code (U42) BlueTEC (SCR) diesel exhaust treatment)
- Temperature sensor upstream of diesel particulate filter (B19/9) (with code (474) Particulate filter)
- Temperature sensor upstream of turbocharger (B19/11)
- Pressure sensor downstream of air filter (B28/5)
- Pressure differential sensor (DPF) (B28/8) (with code (474) Particulate filter)
- DPF pressure differential sensor for OBD (B28/16) (with code (U42) BlueTEC (SCR) diesel exhaust treatment and code (494) USA version)
- Accelerator pedal sensor (B37) - potentiometer 1
- Accelerator pedal sensor - potentiometer 2
- Exhaust back pressure sensor (B60)
- Crankshaft Hall sensor (B70)
- Condensation sensor for fuel filter with heating element (B76/1) (with code (U41) Fuel/water separator and lubrication package) for model 164.1/8 up to 30.06.10 and for model 251.1 up to 31.07.10 or with code (71o) Retrofitted heated fuel filter
- Right hand and left hand intake port shutoff end position sensor (B96/1, B96/2) (with code (U42) BlueTec (SCR) diesel exhaust treatment and code (494) USA version)
- 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)
- 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)
- EGR [AGR] cooler bypass flap switchover valve (Y85)
- Quantity control valve (Y94)

LIN signals
- Alternator interface via drive LIN (LIN C1)
- Alternator (G2)
- Glow time output stage (N14/3)
- Condensation sensor for fuel filter with heating element actuation heating element and condensation sensor status (for model 164.1/8 as of 01.07.10 and for model 251.1 as of 01.08.10)

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

NOx control unit downstream of diesel particulate filter (N37/7) (with code (U42) BlueTEC (SCR) diesel exhaust treatment)
- NOx concentration in the exhaust
- O2 concentration in the exhaust

NOx control unit downstream of SCR catalytic converter (N37/8) (with code (U42) BlueTEC (SCR) diesel exhaust treatment)
- NOx concentration in the exhaust
- O2 concentration in the exhaust

AdBlue(R) control unit (N118/5) (with code (U42) BlueTEC (SCR) diesel exhaust treatment)
- Reduction agent quantity to be injected for NO x reduction
- Injected reduction agent quantity for cooling the AdBlue(R) metering valve (Y129)
- Fill level status in the AdBlue(R) tank
- Requested diagnostic data

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)) NOx control unit downstream of diesel particulate filter (with code (U42) BlueTEC (SCR) diesel exhaust treatment)
- Diagnosis request NOx control unit downstream of SCR catalytic converter (with code (U42) BlueTEC (SCR) diesel exhaust treatment)
- Diagnosis request

EZS control unit
- Start enable request (drive authorization system)

AdBlue(R) control unit (with code (U42) BlueTEC (SCR) diesel exhaust treatment)
- Request for reduction agent injection
- Specification of the reduction agent quantity to be injected
- Specification of the run-on period of the control units
- Diagnosis request

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.