Component Description For Exhaust Aftertreatment Control Unit - GF14.40-P-3030OGF

ENGINE 642.8 in MODEL 166 as of model year 2016 

ENGINE 642.8 in MODEL 292 

Shown on model 166.0 from the rear 

Location 

The AdBlue® control unit is located at the rear right.

Tasks 

The AdBlue® control unit controls the following tasks based on a characteristics map:

• AdBlue® delivery
• Fuel injection
• Antifreeze protection and recirculation

Input and output signals 

The following input signals are evaluated by the AdBlue® control unit and the respective output signal is issued:

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

Direct input signals 

• Circuit 31
• Circuit 30, via circuit 87 for the AdBlue® relay
• AdBlue® fill level sensor signal (A103/1b5)
• AdBlue® tank temperature sensor signal (A103/1b1)
• Recording of the power consumption for diagnosis of the AdBlue® delivery pump (A103/2m1)

Direct output signals 

• Supply of AdBlue® delivery pump
• Supply and actuation of the AdBlue® extraction pump (A103/2m2)
• Pulse width modulated signal for actuation of the AdBlue® delivery pump
• Pulse width modulated signal for actuation of the AdBlue® metering valve (Y129)
• Power supply to the heating element for the AdBlue® tank (A103/1r1)
• Power supply to the heating element for the AdBlue® pressure line (R7/1)

CAN input signals 

• Request for reduction agent injection
• Specification of the reduction agent quantity to be injected
• Specification for the run-on time of the AdBlue® control unit
• Diagnosis request

CAN output signals 

CDI control unit 

• Reduction agent quantity to be injected for NO_x reduction
• Reduction agent quantity injected for cooling the AdBlue® metering valve
• Fill level status in the AdBlue® container
• Requested diagnostic data

AdBlue® delivery 

• Feed to AdBlue® delivery pump to obtain the operating current consumption as a basis for diagnosis of the AdBlue® delivery pump
• Actuation of AdBlue® delivery pump, to generate a pressure of 5 bar before and during the injection of reducing agent for nitrogen oxide (NO_x ) reduction. The delivery pressure is adjustable by the control unit software and can be different according to the variant.
• Actuation of the AdBlue® delivery pump to generate a pressure of 5 bar before and during injection of the reduction agent for cooling the AdBlue® metering valve
• Actuation of the AdBlue® metering valve for ventilation of the AdBlue® pressure line when filling the AdBlue® pressure line

Fuel injection 

• Actuation of the AdBlue® metering valve during the reduction agent injection for NO_x reduction

Antifreeze protection and recirculation 

• After "circuit 15 ON", the pump is given an initial run (warm-up) if the weather is cold. The pump flow serves to remove the friction in the case of cold, so that the desired pressure can be made available as soon as possible after the pressure request.
• Actuation of the AdBlue® tank heating element to liquefy the AdBlue® reduction agent in the AdBlue® tank (A103/1r1), which freezes at approximately -10°C
• Actuation of the AdBlue® delivery module heating element (A103/2) and the AdBlue® pressure line heating element to ensure flowability of the AdBlue® reduction agent (which freezes at approximately -10°C) in the AdBlue® delivery module (A103/2) and in the pressure line to the AdBlue® metering valve
• Actuation of the AdBlue® extraction pump (A103/2m2) for return delivery of the AdBlue® reduction agent in the pressure line to the AdBlue® tank during power-down of the AdBlue® control unit after "circuit 15 OFF"
• The AdBlue® metering valve can be actuated without the nozzle needle being opened. This serves to heating of the valve.

  

  The duration of the return flow of the AdBlue® reduction agent and the duration of the pressure line filling dependent on the length of the AdBlue® pressure line.

  

  The quantity of reduction agent injected by AdBlue® the metering valve is sent by the AdBlue® control unit via the drive train sensor CAN (CAN I) to the CDI control unit. This is taken into account in the subsequent computation of the necessary quantity of reduction agent by the CDI control unit.

  Wiring diagram of AdBlue control unit

  PE14.40-P-2101-97NBA