Transfer Case Oil Cooling System, Function - GF28.55-P-1002AVO
Model 290 with engine 177.9
up to model year 2021
Function requirements for oil cooling system in general
- Circuit 87 ON
- Combustion engine running
- Vehicle driving
Oil cooling system in general
In order to keep the operating temperature of the transfer case constantly low, the oil pump bolted onto the transfer case housing is used.
The transmission oil temperature can be lowered by the oil cooling system and can help prevent damage to the transfer case due to overheating.
Transmission oil heat exchanger
The transmission oil heat exchanger is designed as a plate-type oil cooler. Its operating principle means it can be kept small and provide high efficiency when cooling the transmission oil.
Function sequence for oil cooling system
The transmission oil is pumped by the oil pump in the transfer case to the transmission oil heat exchanger. The transmission oil heat exchanger forms the interface between the transfer case oil circuit and the coolant circuit. The waste heat of the transmission oil is absorbed by the coolant within the transmission oil heat exchanger (plate-type oil cooler).
The transmission oil flows from the transmission oil heat exchanger back to the transfer case.
Control of coolant inflow
Circulation pump 3 low temperature circuit (M43/8) is actuated as required depending on the oil temperature of the automatic transmission and the oil temperature of the transfer case. It pumps the coolant for cooling to the automatic transmission and the transfer case. The oil temperature of the transfer case is transmitted via a direct line from the transmission oil temperature sensor (B91) to the all-wheel drive control unit (N45).
| Overview of system components, automatically controlled all-wheel drive (4MATIC) | GF28.00-P-9998AVO |