Component description of transfer case control unit - GF28.19-P-3200VG

MODEL 164.1 with ENGINE 156, 272, 273, 629, 642 with TRANSMISSION 722.9 as of Model Year 09/Modification Year 08 model refinement package with CODE (430) Off-road package 

MODEL 164.8 with ENGINE 273, 629, 642 with TRANSMISSION 722.9 as of Model Year 09/Modification Year 08 with CODE (430) Off-road package 

View of front passenger footwell 

Location 

The transfer case control unit is located in the front passenger footwell.

Task 

General 

The transfer case control unit monitors and shifts the transfer case according to:

• Vehicle speed
• Selector lever in position "N"
• "Low Range" switch (N72s31) actuated
• Position of transfer case actuator motor (M46/2)

The following control functions are performed by the transfer case control unit:

• Pre-control of the locking torque
• Slip-dependent lock control/slip control
• Lock actuation when braking
• Antilock brake system (ABS) control
• Electronic Stability Program (ESP) control
• Lock overload protection

The following basic functions are performed by the transfer case control unit:

• Computation of engine torque
• Computation of vehicle reference speed
• Cornering recognition
• Tire tolerance detection
• Flash programming
• Diagnosis
• Caster
• Variant coding
• Calibration run

CAN data bus 

The transfer case control unit is connected to the CAN system of the vehicle via the engine compartment CAN (CAN-C).

Input and output signals 

The following input signals are evaluated by the transfer case control unit and the corresponding output signals are issued:

• Direct input signals 
• Direct output signals 
• CAN input signals 
• CAN output signals 

Direct input signals 

• Circuit 15
• Circuit 30
• Circuit 31
• Actuator motor rotation direction sensor
• Actuator motor speed sensor
• Actuator motor temperature
• Transfer case absolute sensor (B57)

Direct output signals 

• Sensor supply voltage (5V)
• Sensor ground
• Transfer case actuator motor
• Transfer case switchover magnet (Y108)

CAN input signals 

Instrument cluster (A1) 

• Status of displayed speed

Intelligent servo module for DIRECT SELECT (A80) 

• Position of range selector lever

CDI control unit (N3/9) or ME-SFI [ME] control unit (N3/10) 

• Engine speed
• Engine torque
• Pedal value

Rear axle differential lock control unit (N15/9) 

• Actual value of rear differential lock

AIRmatic control unit (N51) 

• Vehicle level status

Steering column tube module (N80) 

• Steering wheel angle status
• Left multifunction steering wheel button group signal (S110)
• Right multifunction steering wheel button group signal (S111)

ESP control unit (N47-5) 

• ABS request
• ESP requirement
• DSR LED (D  ownhill S  peed R  egulation) ON/OFF

Fully integrated transmission control unit (VGS) (Y3/8n4) 

• Actual/target gear

Central gateway control unit (N93) 

• Low Range ON/OFF
• Specified value of differential locks
• Diagnosis request

CAN output signals 

Instrument cluster (A1) 

• Transfer case status for multifunction display (A1p13)

CDI control unit (N3/9) or ME-SFI control unit (N3/10) 

• Transfer case status

Rear axle differential lock control unit (N15/9) 

• Specified locking torque

ESP control unit (N47-5) 

• Transfer case status
• DSR variable speed limiter ON/OFF actuated
• Actual value of differential locks
• Specified locking torque

Central gateway control unit (N93) 

• Actual value of differential locks
• Transfer case LED status
• Diagnostic data

Fully integrated transmission control unit (VGS) (Y3/8n4) 

• Transfer case status
• Status, shift to "N"

	Wiring diagram for transfer case control unit	N15/7	PE28.19-P-2101-99MAA
	Wiring diagram for rear differential lock control unit	N15/9	PE35.40-P-2101-99MAA