VOLVO
TRM-E001 - Control module communication. Faulty communication
System
Trailer Module (TRM)
Volvo models this fault code applies to
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?
The tow hitch control module (TRM) has registered a serious disturbance on the low-speed side of the CAN network, which blocks normal communication. The fault can come from a short circuit or break in the CAN wires, or from a fault in another control module on the same network. The trailer lamps may then behave incorrectly.
Possible causes
- Short circuit between the CAN wires
- Open circuit in one of the CAN wires
- Internal fault in the tow hitch control module (TRM)
- Internal fault in another control module on the same part of the CAN network
What you can do
- 1Read the fault codes in the central electronic module (CEM) and in other control modules, and deal with them first
- 2Check the connectors and wiring in the CAN network for looseness, corrosion and damage
- 3Have a workshop measure the resistance of the CAN network, as this needs measuring and diagnostic equipment
- 4Leave the central electronic module (CEM) in place for this code unless the workshop finds an internal fault in it
- 5Clear the code only once the fault has been fixed, and check that it does not return
Symptoms you may notice2
- The trailer lamps do not work as they should
- Trailer lighting does not work
What the fault can affect2
- The control module shuts itself off from the CAN network (bus-off)
- The control module stays inactive until its power is cut
General guidance for car owners. Diagnosis on the car can point to a different cause.