VOLVO
CEM-DD02 - LIN-bus 3. Communication 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 modelsC30 (2007–2013), C30 Electric (2011–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
Disturbance on the LIN bus stops the central module from reaching the siren or the remote receiver. The cause may lie in the wiring, in a faulty unit, in a short circuit or in a break in the wires. The siren may then sound erratically or go silent completely, and the alarm cannot be controlled.
Possible causes
- Open circuit in one of the LIN wires
- Internal fault in another control module on the same part of the LIN network
- Short circuit between the LIN wires
What you can do
- 1Test the alarm twice with the remote control and see whether the siren responds each time
- 2With a multimeter, check the wires to the siren and the remote receiver for breaks and for contact with ground or voltage
- 3Look at the connections at the siren and the remote receiver for corrosion or loose connectors
- 4Clear the fault code and road test to see whether it returns
- 5If the wires are intact, have a workshop find which unit is silent and replace it
Symptoms you may notice2
- The siren works intermittently or not at all
- The alarm cannot be armed or disarmed
General guidance for car owners. Diagnosis on the car can point to a different cause.