Sentronic is the brand name of a range of automatic transmissions with a manual shift function , which Saab models are equipped with. These were introduced in the early 2000s with the release of the second generation Saab 9-3– and Saab 9-5 models.
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How Sentronic works
The main components of the gearbox were planetary gears and a torque converter, which had a lock-up function in certain modes. In manual mode, the driver was able to optimally use the engine's torque, which positively affected driving dynamics and performance on slippery surfaces, dirt roads and when driving down a slope. To switch to manual mode, the driver had to move the shift lever to the “M” position. Pushing the shift lever in the “+” or “–” direction has shifted to a higher or lower gear. Rocker switches were also installed.
Known Sentronic transmissions
| Transmission code | Manufacturer | Number of gears | Max. Displacement in liters | Max. Engine torque, N–m | Type of drive | Year of manufacture | Models |
| FA57 (AF33, AW55-50SN) | Aisin | 5 | 3.5 | 330 | Front wheel drive | 2000 | Saab 9-3; Saab 9-5 |
| AF40-6 (AWTF-80SC) | Aisin | 6 | 2.5 | 450 | Front wheel drive, all wheel drive | 2001 | Saab 9-5; Saab 9-3 |
Known defects in the Sentronic transmission
| Defects | Transmission |
| The electromagnets become clogged with wear residue from the friction linings of the clutch packs. | FA57 (AF33, AW55-50SN ) |
| Lack of oil wears out the mechanical parts of the gearbox. | FA57 (AF33, AW55-50SN) |
| The housing of the valve and the bushing of the planetary gear fail. | FA57 (AF33, AW55-50SN) |
| After a certain mileage occurs jerking up. This is an indication of a valve body malfunction. | AF40-6 (AWTF-80SC) |
| The brake band is wearing out. | AF40-6 (AWTF-80SC) |