VOLVO
CEM-9D01 - Communication with RRX control module. Comminicational problems
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
5 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The central electronic module (CEM) communicates with the remote receiver module (RRX) over a LIN serial link. The fault is stored when the communication is incorrect or missing altogether.
Possible causes
- The remote receiver (RRX) is not receiving supply voltage
- Open circuit in the ground cable to the remote receiver module
- Broken signal wire to the remote receiver module
- Internal fault in the remote receiver module
What you can do
- 1Check that the remote receiver gets power and that the earth point is clean and secure
- 2Use a multimeter to check that the supply cable has voltage and that the earth cable has no open circuit
- 3Check the connectors and wiring to the remote receiver for chafing, corrosion and loose connections
- 4Test the remote control by locking and unlocking the car; if it works, the communication is probably fine
- 5If no fault is found in the wiring, the remote receiver may need replacing, which a workshop should do
Symptoms you may notice3
- Central locking does not work, either when locking or unlocking
- Amber warning symbol and text message in the display
- Warning lights and chimes do not work as they should, and the tyre pressure monitoring shows no indication
General guidance for car owners. Diagnosis on the car can point to a different cause.