VOLVO
CEM-U010100 - Lost Communication with Transmission control module. General Failure Information. No sub type information
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:
7 modelsS60 (2011–), S80 (2007–), V60 (2011–), V60 Cross Country (2015–), V70 (2008–), XC60 (2009–), XC70 (2008–)
What does this fault code mean?
The fault code means that communication between the control module storing the fault and the TCM is disturbed or has stopped. The fault may lie in the CAN network or in the power supply and earth of the TCM, and does not point to one individual control module. The code can stay in memory even after communication works again.
Possible causes
- No power supply to the TCM
- Broken ground wire to the TCM
- Poor contact in the connections
- Open or shorted CAN wiring
- A TCM not intended for the car, such as a used module with other software or hardware
What you can do
- 1Switch the ignition on and see whether the gear selector lighting comes on. If it does not, there is probably a power supply fault to the TCM
- 2Look at the TCM fuse in the engine bay fusebox. If it is blown, check the circuit after it for a short to ground, then replace it
- 3Follow the wire from the fusebox to the TCM for breaks, and check the ground connection for loose contact and oxidation
- 4With a diagnostic tool, check whether the TCM responds. A response means communication works at that moment, and the fault may be gone
- 5If the fault returns, have a workshop check the network. Replace the CEM only if testing shows a damaged control module
Symptoms you may notice2
- Gear changes do not happen
- Check engine lamp comes on or a message appears in the display
General guidance for car owners. Diagnosis on the car can point to a different cause.