VOLVO
CEM-U201F83 - External receiver. Bus Signal / Message Failures. Value of signal protection calculation incorrect
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsV40 (2013–), V40 Cross Country (2013–)
Show models by year and engine (2)
What does this fault code mean?
The central electronic module (CEM) receives an incorrect message from the remote receiver module (RRX) over the LIN bus. The cause may be poor contact or oxidation in the connectors, or a damaged remote receiver. The check runs with the ignition in position II.
Possible causes
- Poor contact, oxidation or high resistance at the connectors or joints
- Damaged remote receiver module (RRX)
What you can do
- 1Test locking and unlocking with several remote keys to see whether the fault follows the key or the car
- 2If a low battery warning for the remote keys appears, replace the battery in the key and test again
- 3Check that the connectors at the central electronic module (CEM) and the remote receiver (RRX) are secure and free from oxidation
- 4Follow the wiring between the CEM and the remote receiver and look for chafing, pinch damage and breaks
- 5Check that the earth wire to the remote receiver is secure and intact
- 6Use a multimeter to confirm supply voltage at the remote receiver with the ignition on; if it is missing, have a workshop check the wiring
Symptoms you may notice3
- A yellow warning symbol and a text message appear in the display
- The remote key cannot lock or unlock the car
- The tyre pressure warning lights up or behaves abnormally
General guidance for car owners. Diagnosis on the car can point to a different cause.