VOLVO
REM-E001 - Control module communication. Faulty communication
System
Rear Electronic Module (REM)
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?
The control modules in the car communicate over the CAN network. The rear electronic module (REM) has registered serious interference in that communication, which sets the code. The fault may be in the wiring, in a connector, or in a control module on the same part of the network.
Possible causes
- Short-circuit in the CAN wiring
- Open circuit in one of the CAN wires
- Internal fault in the REM
- Internal fault in another control module on the same part of the CAN network
What you can do
- 1Read the codes in all control modules first and work through them in that order, then clear them and road test the car to see which ones come back
- 2Check whether there are codes for lost communication stored in the central electronic module (CEM), and deal with those first
- 3Disconnect the battery negative lead and use a multimeter to check that the CAN wires are not shorted to ground or voltage and have no open circuit
- 4Twist the wiring harness and wiggle the connectors where they are reachable during the test, and see whether anything changes
- 5Have a workshop with diagnostic equipment identify which control module is disturbing the network before any module is replaced
Symptoms you may notice5
- The fuel gauge reads zero although fuel is in the tank
- Rear window heating does not work
- Folding headrest does not work
- Rear doors and the fuel filler cap do not lock or unlock
- On the S80 the trunk lid cannot be unlocked; on the V70, XC70 and XC90 the tailgate or trunk lid does not lock or unlock
What the fault can affect2
- The control module switches itself off (bus-off) and stays off until its power supply is cut
- When power is reconnected, the control module tries to communicate again
General guidance for car owners. Diagnosis on the car can point to a different cause.