VOLVO
CEM-6C49 - Transponder communication. Faulty signal. Intermittent fault
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
This fault code has different meanings depending on model, model year or engine. Select the meaning that applies to your car.
Applies to the following models:
5 modelsS60 (2001–2009), S80 (1999–2006), V70 (2000–2008), V70 XC / XC70 (2001–2007), XC90 (2003–)
What does this fault code mean?
When the ignition is switched on, the CEM reads the transponder. The fault code is set if the transponder answers with a known code but another part of the transponder communication is wrong or fails. The fault is intermittent, so it may have occurred earlier without being active now. Several keys or other transponders placed too close to the antenna can cause it, and then the engine does not start.
Possible causes
- Several keys are close together, so several transponder codes are read at once
- A door key with an electronic chip sat too close to the antenna during reading
- An automatic toll transponder was fitted too close to the antenna unit
- Strong electrical interference during the start-up communication
- The key is for another vehicle, and its security code does not match this car
What you can do
- 1Check that keys on the same ring hang freely and do not touch the key in use, and that no other transponder is near the ignition switch
- 2Check that the colour marking on the key head is grey or red; black or blue means a different Volvo model
- 3Try the same key a few more times, taking it out of the ignition switch for two seconds or more between attempts
- 4Clear the fault code and road test the car to see whether it returns
- 5If the key is faulty, a workshop should order and program a new one
Symptoms you may notice1
- The engine does not start
General guidance for car owners. Diagnosis on the car can point to a different cause.