VOLVO
ECM-0551 - Power steering. Faulty signal
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS40 (1996–2004), V40 (1996–2004)
Show models by year and engine (2)
What does this fault code mean?
The engine control module monitors the pressure sensor in the power steering. If the signal is too low when the steering wheel is turned at high engine speed and high engine load for a set time, the fault is set. The cause may be a signal wire shorted to ground, or a defective pressure sensor.
Possible causes
- Signal wire short-circuited to ground
- Defective power steering pressure sensor
What you can do
- 1Read out the fault code, erase it and road-test with the steering wheel turned to different positions to see whether it returns
- 2If you have a diagnostic tool, read the pressure sensor value in live data with the engine idling and check that it changes when the wheel is turned
- 3Switch off the ignition and check the sensor connector for looseness, contact resistance and oxidation
- 4On cars with hydraulic power steering, check that the fluid level is correct and look for leaks at the pump and hoses
- 5Because steering is a safety function, have a workshop check the pressure sensor and its signal wire if the fault remains
Symptoms you may notice1
- The malfunction indicator lamp (MIL) is lit
General guidance for car owners. Diagnosis on the car can point to a different cause.