Turbocharger: Description and Operation

Coolant Pump For Charge Air Cooler

Coolant pump for charge air cooler
Due to the turbocharging and the compact arrangement of the exhaust turbocharger in the V-room the N63 engine generates a lot of heat. Great importance is attributed to the cooling accordingly. In addition, an indirect charge air cooling was developed for the first time with which the charge air is cooled via an air/coolant heat exchanger. The engine and charge air cooling have 2 separate cooling circuits. The engine control unit is also integrated in the cooling circuit for the charge air cooling.

Functional description
The electrical coolant pump works according to the principle of a centrifugal pump. The coolant pump is integrated in the cooling circuit (low temperature) and is used for the charge air cooling. Communication from the coolant pump to the engine control is effected via local interconnect network bus. The speed specification and the read-out of the current pump speed, as well as other pump values, are realized.

The following values are used for the activation:
- Ambient temperature
- Difference between charge air temperature and ambient temperature







The coolant pump receives the setpoint value specification via local interconnect network bus from the engine control. The following pump values are reported back:
- Current engine speed
- Power consumption
- Voltage
- Temperature of evaluation electronics
- Fault status

Structure and inner electrical connection
The local interconnect network bus is a single-wire bus with a maximum data transfer rate of 20,000 Bit/s. The local interconnect network bus is based on the principle of master and slave. This means the master initiates every communication. The master sends the message header to which the slave responds with the data. The data sent by the slave are available to both the master and other slaves.







Characteristic curve and setpoint values
The coolant pump works in the engine speed range of 24 to 6000 rpm. The permissible coolant temperature is between -40 °C and 128 °C.
The hydraulic data is dependent on the temperature. Mainly at very low temperatures the viscosity of the coolant has a huge impact on the maximum engine speed and the hydraulic values.







Observe the following setpoint values for the coolant pump for the charge air cooler:

Size Value
Voltage range (full 12.5 to 16 volts
power output)

Voltage range (reduced 8 to 12.5 volts
power)

Power 50 Watts

Maximum current consumption 6.5 A
in normal operating mode

Temperature range of coolant -40 to 128 deg C
temperature

Temperature range -40 to 140 °C

Diagnosis instructions

Failure of the component

If the coolant pump for the charge air cooler fails, the following behavior is to be expected:
- Fault entry in the engine control unit
- Emergency operation of the coolant pump for the charge air cooler if there is voltage of at least 0.6 volts at the inlet for the emergency operation: Maximum delivery rate

General notes
The following diagnosis options are available for the coolant pump:
- Engine speed monitoring
- Signal line for emergency operation
- Coolant pump, switch-off
- Coolant pump, power reduction

We can assume no liability for printing errors or inaccuracies in this document and reserve the right to introduce technical modifications at any time.