VOLVO
ECM-P050383 - Vehicle Speed Sensor A Intermittent/Erratic/High. Bus Signal / Message Failures. Value of signal protection calculation incorrect
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 brake control module (BCM) has found that the speed signal is not correct, because the check value (checksum) in the message does not match. It sends a fault message to the engine control module (ECM), which sets the code. The code is also stored in the BCM, where diagnosis is carried out. The fault is intermittent.
Possible causes
- Contact resistance in the CAN connections
- Break in one or both CAN wires
- One or both signal wires shorted to ground, supply voltage or each other
- Faulty brake control module (BCM)
- Faulty engine control module (ECM)
What you can do
- 1Read the codes in the brake control module and the engine control module and note which are stored
- 2Repair the fault in the brake control module, which sends the signal, before clearing the code in the engine control module
- 3Check the connectors in the CAN connections between the modules for loose, corroded or chafed areas
- 4Use a multimeter to check that the wire has no contact with ground or supply voltage, and that the CAN wires have no break
- 5If you have a diagnostic tool, read the speed value in the brake control module live data and check that it follows the car's actual speed on a road test
- 6Do not work on the brake control module yourself; if the code returns, have a workshop carry out the checks that need diagnostic equipment
Symptoms you may notice3
- Cruise control does not engage
- Cruise control does not hold the set speed and disengages
- Autostart does not work
What the fault can affect1
- The speed value from the brake control module is replaced by a default value
General guidance for car owners. Diagnosis on the car can point to a different cause.