Transfer Case Oil Cooling System, Function - GF28.55-P-1002AVL
Model 213 with transmission 725.096 up to model year 2021
View of transmission oil cooling circuit, shown up to model year 2019
On vehicles up to model year 2019, the oil pump (10) is integrated into the transfer case.
On vehicles as of model year 2019 the outer oil pump is bolted on to the housing of the transfer case.
Function requirements, general
- Combustion engine running
- Vehicle driving
Oil cooling
To keep the operating temperature of the transfer case constantly low and to prevent any overheating damage, the transmission oil is cooled by the transmission oil heat exchanger. The oil pump (10) pumps the transmission oil to the transmission oil heat exchanger. The transmission oil is cooled in the transmission oil heat exchanger and it flows back into the transmission oil reservoir. The waste heat of the transmission oil is absorbed by the coolant.
The transmission oil heat exchanger is designed as a plate-type oil cooler. The transmission oil heat exchanger forms the interface between the transmission oil and the coolant circuit.
The coolant supply is regulated by the low-temperature circuit. The transmission oil temperature sensor (B91) records the transmission oil temperature. The all-wheel drive control unit (N45) reads in the signals from the transmission oil temperature sensor directly. The all-wheel drive control unit then sends information on the transmission oil temperature over the suspension FlexRay (Flex E) to the powertrain control unit (N127). The powertrain control unit actuates the circulation pump 3 for the low-temperature circuit (M43/8) accordingly.
| Overview of system components, automatically controlled all-wheel drive (4MATIC) | GF28.00-P-9998AVL |