VOLVO
CEM-DE2F - Communication with PSR control module. Signal missing
System
Central Electronic Module (CEM)
Volvo models this fault code applies to
Applies to the following models:
1 modelC70 (2006–2013)
Show models by year and engine (1)
What does this fault code mean?
The CEM has lost contact with the right front seat module (PSR), so automatic adjustment of the right seat and the outer mirror does not work. The fault is most often caused by supply, earth or a connector at the module, or by a break in the LS-CAN wiring.
Possible causes
- No supply to the PSR
- Open circuit in the earth wire to the PSR
- Poor contact in the connections
- Open circuit in the LS-CAN wires to the PSR
- The PSR does not suit the car, for example a used module with different software or hardware
What you can do
- 1Try adjusting the right seat with the controls. If it does not move at all, the PSR or its supply is probably at fault
- 2Check the right seat fuses in the engine bay fuse box and in the CEM. If one has blown, check its circuit for a short to earth
- 3Use a multimeter to confirm the wire from the CEM to the PSR has no break and no short
- 4Check the earth and the connector at the PSR for loose contact, corrosion and damage
- 5With a diagnostic tool, try to read the PSR ID. If it reads, the communication is probably fine and the fault may be intermittent
- 6Do not replace the CEM for this code; the fault points to communication on the CAN network, not to the CEM
Symptoms you may notice1
- Automatic adjustment of the right front seat and outer mirror does not work
General guidance for car owners. Diagnosis on the car can point to a different cause.