VOLVO
ECM-P050168 - Vehicle Speed Sensor "A" Range/Performance. Algorithm Based Failures. Event information
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
1 modelS60 (2011–)
Show models by year and engine (1)
What does this fault code mean?
The engine control module (ECM) works out the relationship between engine speed and the vehicle speed value that the brake control module (BCM) reports and compares it with the gear ratios the transmission can have. The code is set when the result is not plausible. It is set in the BCM first and then in the ECM, so diagnosis should start in the BCM. This is a follow-on code.
Possible causes
- Incorrect speed information coming from the BCM
What you can do
- 1Read the codes in the brake control module (BCM) first and repair the fault there, as this code is a follow-on code
- 2Clear the code in the BCM after the repair, then the code in the ECM. The ECM code cannot be cleared until the BCM code has been repaired
- 3If you have a diagnostic tool, compare the speed value in the BCM live data with the speed shown while driving. The value should follow the car's speed without jumps
- 4Road test the car to see whether the code returns once the BCM fault is repaired
- 5Do not work on the brake control module yourself; have a workshop carry out the checks that need diagnostic equipment
Symptoms you may notice3
- Autostart does not work
- Cruise control does not engage
- Cruise control does not hold the set speed and disengages
What the fault can affect2
- On manual gearboxes the speed signal is set to a default value
- On automatic gearboxes a secondary speed signal from the transmission control module (TCM) is used instead
General guidance for car owners. Diagnosis on the car can point to a different cause.