Component Description For Exhaust Aftertreatment Control Unit - GF14.40-P-3030OLG
ENGINE 642.826, 651.960 in MODEL 166 up to model year 2016
with CODE U42 (BlueTEC diesel exhaust treatment (SCR))
Shows model 166.0
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, over circuit 87 relay for the AdBlue® supply (K277)
- Sensor signal from AdBlue® pressure sensor (A103/2b1)
- Sensor signal from "Full" fill level sensor (A103/1 b2)
- Sensor signal from "Reserve" fill level sensor (A103/1 b3)
- Sensor signal from "Empty" fill level sensor (A103/1 b4)
- Sensor signal of AdBlue® container temperature sensor (A103/1 b1)
- Recording of the power consumption for diagnosis of the AdBlue® delivery pump (A103/2m1)
Direct output signals
- Supply for circuit 31 for the AdBlue® supply relay
- Common power supply for circuit 30 of the AdBlue® delivery pump and the AdBlue® switchover valve (A103/2y1)
- Supply of circuit 31 for the AdBlue® delivery pump
- Pulse width modulated signal for actuation of the AdBlue® delivery pump
- Control signal circuit 31 for actuation of AdBlue® switchover valve
- Pulse width modulated signal for actuation of the AdBlue® metering valve (Y129)
- Power supply for the AdBlue® container heating element (A103/1 r1)
- Power supply for AdBlue® delivery module heating element (A103/2r1)
- Power supply for the AdBlue® pressure line heating element (A103/1 r2)
CAN input signals
CDI control unit (N3/9)
- Request for reduction agent injection
- Specification of the reduction agent quantity to be injected
- Specification of the run-on time of the control units
- Diagnosis request
CAN output signals
CDI control unit (N3/9)
- Reduction agent quantity injected for NOx 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 the AdBlue® delivery pump to obtain the operating current consumption as a basis for the 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 (NOx) 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 injection of the reducing agent for NOx reduction and for cooling the AdBlue® metering valve
Antifreeze protection and recirculation
- After "circuit 15 ON", the pump is given an initial run (warm-up) if the weather is cold. The initial run serves to remove the friction in cold weather so that the required compression can be made available as soon as possible when pressure is requested
- Actuation of the AdBlue® container heating element to liquefy the AdBlue® reduction agent in the AdBlue® container, which freezes at about -10 °C
- Actuation of the AdBlue® delivery module heating element and AdBlue® pressure line heating element to ensure flowability of the AdBlue® reduction agent (which freezes at about -10 °C) in the AdBlue® delivery module (A103/2) and in the pressure line to the AdBlue® metering valve
- Actuation of the AdBlue® delivery pump, AdBlue® switchover valve and AdBlue® metering valve to return the AdBlue® reduction agent from the pressure line to the AdBlue® tank during power-down of the AdBlue® control unit after "circuit 15 OFF"
The duration of the return flow of the AdBlue® reduction agent and the duration of pressure line filling depend on the length of the 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 for AdBlue® control unit | N118/5 | PE14.40-P-2101-97NAA |