Rear Control Unit, Component Description - GF54.21-P-4134LF

Model 217 

Model 217.3 

Model 217.4 

Location 

On model 217.3 the left rear control unit is located on the rear panel of the trunk.

On model 217.4 the rear control unit is located on a bracket behind the rear wall paneling.

Tasks 

The rear control unit has the following tasks:

• Reading in of sensors and signals 
• Evaluation of input factors 
• Actuation of components 
• Sending signals 

Reading in of sensors and signals 

The input factors are read in over the following connections:

• Direct lines 
• Left rear-LIN (LIN B9) (with code 872 (Seat heater in rear)) 
• Right rear-LIN (LIN B10) (with code 872 (Seat heater in rear)) 
• Interior CAN (CAN B) 

Direct lines 

The rear control unit reads in the signals from the following components over direct lines:

• Model 217.3:
  • Left belt extender Hall sensor (A10b1) in left belt extender (A10)
  • Right belt extender Hall sensor (A11b1) in the right belt extender (A11)
  • Hall sensor in left rear power window motor (M10/5)
  • Hall sensor in right rear power window motor (M10/6)
• Model 217.4:
  • Temperature sensor (A7/5b1) in soft top control hydraulic unit (A7/5)
  • Left belt extender Hall sensor in left belt extender
  • Right belt extender Hall sensor in the right belt extender
  • Trunk lid lock main catch switch (A85/5s1) in trunk lid lock (A85/5)
  • Trunk lid/liftgate position sensor (B24/16)
  • Left trunk partition Hall sensor (B100/2)
  • Right trunk partition Hall sensor (B100/3)
  • Left rear Hall sensor in power window motor
  • Right rear Hall sensor in power window motor
  • Left rear seat head restraint height adjustment Hall sensor (M18/13b1) in left rear seat head restraint height adjustment set adjustment motor (M18/13)
  • Right rear seat head restraint height adjustment Hall sensor (M18/14b1) in right rear seat head restraint height adjustment set adjustment motor (M18/14)
  • Trunk partition motor (M24/11)
    • Trunk partition open/closed Hall sensor (M24/11b1)
    • Trunk partition drive frictional connection Hall sensor (M24/11b2)
  • Limit switch in draft stop actuator motor (M96/1)
  • Limit switch in wind deflector actuator motor (M96/2)
  • Soft top control switch (S84)
    • Draft stop and wind deflector button (S84s4)
    • Electric window lifting mechanism central operating switch (S84s5)
  • Left soft top locked limit switch (S84/1)
  • Right soft top locked limit switch (S84/2)
  • Soft top open limit switch (S84/3)
  • Left lower soft top bow locked limit switch (S84/6)
  • Right lower soft top bow locked limit switch (S84/7)
  • Top soft top bow limit switch (S84/8)
  • Left soft top compartment lid open limit switch (S84/26)
  • Left soft top compartment lid locked limit switch (S84/27)
  • Right soft top compartment lid locked limit switch (S84/28)
  • Soft top closed limit switch (S84/31)
  • Soft top lock open limit switch (S84/34)
  • Soft top lock locked limit switch (S84/35)
  • Trunk partition switch (S138/3)

Left rear LIN (with code 872 (Seat heater in rear)) 

The rear control unit reads in the signals from the left rear seat heater switch (S51/3) over the left rear LIN.

Right rear LIN (with code 872 (Seat heater in rear)) 

The rear control unit reads in the signals from the right rear seat heater switch (S51/4) over the right rear LIN.

Interior CAN 

The rear control unit reads in various functions for the control system including the following signals over the interior CAN:

• Circuit 15 status
• PRE-SAFE® adjustment request
• Head restraint lowering mechanism request
• Open/close rear window request
• Crash signal

Evaluation of input factors 

The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Actuation of components 

The rear control unit actuates the following components over direct lines:

• Model 217.3:
  • Left seat belt extender electric motor (A10m1)
  • Right seat belt extender electric motor (A11m1)
  • Left rear power window motor
  • Right rear power window motor
• Model 217.4:
  • Soft top control hydraulic unit
    • Soft top control hydraulic unit electric motor (A7/5m1)
    • Solenoid valve 1 (A7/5y1)
    • Solenoid valve 2 (A7/5y2)
    • Solenoid valve 3 (A7/5y3)
    • Solenoid valve 4 (A7/5y4)
• Left belt extender electric motor
• Right belt extender electric motor
• Trunk lid/liftgate control warning buzzer (H4/60)
• Left rear power window motor
• Right rear power window motor
• Seat adjustment motor for height adjustment of head restraint on left rear seat
• Seat adjustment motor for height adjustment of head restraint on right rear seat
• Trunk partition motor
• Front soft top lock motor (M47/1)
• Draft stop actuator motor
• Wind deflector actuator motor
• Soft top control switch
  • LED in draft stop and wind deflector button

Sending signals 

The rear control unit also sends signals over the interior CAN:

• Seat belt extender status
• Rear electric window lifting mechanism status
• Soft top status (model 217.4)

Wiring diagram rear control unit

PE54.21-P-2110-97SEA