DSA (Dynamic Stability Assistance) is a dynamic stability control system designed specially for compact Volvo models. It prevents the drive wheels from slipping and improves their grip on wet and slippery surfaces. The system contributes to rapid acceleration and helps to maintain the intended path during maneuvering.
How DSA operates
The rotation speed of each wheel is monitored with the help of the ABS sensors. If one of the front wheels rotates faster than the rear wheels, the system sends a signal to the FENIX engine control unit. It turns off one or more fuel injectors, thus limiting the engine torque, until the traction is restored. The amount it is reduced by depends on the rotation speed of the crankshaft, the throttle valve position, and the intake manifold pressure. The system doesn’t engage the brake mechanisms – this is what differentiates it from a traction control system.
Popular Volvo models equipped with DSA
- S40 VS, 644
- V40 VW, 645
Causes of malfunctions
- Faulty wheel speed sensors.
- Oxidation of the oxygen sensor terminals.
- Engine malfunctions.
- Control unit failure.