A4S 310R

A4S 310R






















Introduced as the THM R1 on the 1990 525i, the transmission was later identified as the A4S 310R following BMW's new transmission ID convention. This transmission was the first GM transmission used on BMW vehicles for the US. The transmission control system is manufactured by Bosch to BMW specifications.

System Features:
- 55 Pin Control Module
- Adaptive Hydraulic Pressure Control
- Torque Converter Lock Up Control (on/off).
- Reverse Lock out Function
- Downshift Protection
- Shift solenoid control (all free wheel shifts)
- Shift lock solenoid control
- Downshift Inhibit control
- 3 Shift programs:
- Economy
- Sport
- Manual
- Output signal generation of:
- Torque reduction during upshifts
- Torque converter lock status
- Warm Up phase program
- Failsafe Operation (Emergency Program)
- DIS/MoDiC communication for Diagnosis

Output Ratios: 1st gear 2.40:1
2nd gear 1.46:1
3rd gear 1.00:1
4th gear 0.72:1
Reverse 2.00:1