Rear axle level control system control unit, component description - GF32.33-P-3400GV

MODEL 251.0/1 as of Model Year 09/Modification Year 08 with CODE (488) Steel/air suspension 

Location 

The rear axle level control system control unit is located on the control unit retaining plate under the front passenger seat.

Task 

The rear axle level control system control unit has the following tasks:

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

Reading in of sensors, pickups and signals 

The input factors are read in with the following connections:

• Direct line 
• Engine compartment CAN 

Direct line 

The signals from the following components are read via a direct line:

• Left rear level sensor (B22/7)
• Right rear level sensor (B22/10)

Engine compartment CAN 

The rear-axle level control system control unit reads in the following information via the engine compartment CAN.

• Wheel speed, as provided by the ESP control unit (N47-5)
• Rotation angle, recorded by steering angle sensor (N49) and provided by steering column tube module (N80)
• Atmospheric pressure and intake air temperature by CDI control unit (N3/9) (with diesel engine) or provided by the ME-SFI control unit (N3/10) (with gasoline engine)
• Ambient air temperature, over the interior CAN from the AAC [KLA] control and operating unit (N22) (without code (581) Comfort automatic air conditioning) or from the comfort AAC control and operating unit (N22/7) (with code (581) Comfort automatic air conditioning) and forwarded by the central gateway control unit (N93) to the engine compartment CAN

Evaluation of input factors 

The input factors are evaluated by the microprocessor and the corresponding components are actuated.

Actuation of components 

Components are actuated with the following connection:

• Direct line 

Direct line 

The following components are actuated via a direct line:

• Air suspension compressor relay (F58kG) for actuation of AIRmatic compressor unit (A9/1) with the following components:
  • Air compressor motor (A9/1m1)
  • AIRmatic pressure reduction valve (A9/1y1)
• Electronic rear axle level control valve unit (Y36/8) with following components:
  • Left rear level control valve (Y36/8y1)
  • Right rear level control valve (Y36/8y2)

Wiring diagram for level control (NR) control unit

PE32.33-P-2101-99RAA