What does fault code CEM-DE11 mean?

Diagnostic fault code details for CEM-DE11 (Volvo C30 (2007–2013), Volvo C30 Electric (2011–2013), Volvo C70 (2006–2013)). Repair service at OBD Tuning.

VOLVO

CEM-DE11 - Communication with ECM control module. Signal missing

System

Central Electronic Module (CEM)

Volvo models this fault code applies to

Applies to the following models:

5 models

C30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)

Show models by year and engine (5)

What does this fault code mean?

The central module has lost contact with the engine control module (ECM), which controls the engine. The fault can cause starting difficulty, the engine to stall, or the engine to feel sluggish. The cause may be a missing voltage supply or earth to the engine control module, contact resistance at connections, a break in the CAN wiring, or a module that is not intended for this car.

Possible causes

No voltage supply to the engine control module (ECM)
Open circuit in the earth lead to the engine control module (ECM)
Contact resistance at the connections
Open circuit in the CAN high-speed network wiring to the engine control module (ECM)
The engine module does not belong to this car, e.g. a used unit with other software
Several fault codes for communication with other modules on the high-speed network point to a common fault on the CAN network

What you can do

1Look at the engine module fuse in the engine bay fuse box, per the owner's manual. If blown, check the circuit after it for a short to ground before replacing it
2Check that the earth point of the engine control module is clean and tight, with no corrosion
3If you have a diagnostic tool, check whether further communication faults are stored. If so, the fault is probably common to the CAN network and needs a workshop
4If the fault remains, have a workshop check the supply voltage and the CAN wiring, and read the engine control module ID

Symptoms you may notice5

The engine does not start, does not turn over or makes no clicking sound when starting
The engine stalls
The engine feels sluggish
The environmental (engine) warning lamp comes on
A message in the display

General guidance for car owners. Diagnosis on the car can point to a different cause.