VOLVO
ECM-A670 - Communication, transmission control module (TCM). Signal missing
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
3 modelsC30 (2007–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The module gets data from the transmission control module (TCM) over CAN. The code is set when that signal is missing. The fault may lie in the transmission control module or in the communication between the modules, and the malfunction indicator lamp may then light up or behave abnormally.
Possible causes
- The cause lies in the transmission control module (TCM)
What you can do
- 1Read the fault codes in the transmission control module (TCM) first, then in the central electronic module (CEM)
- 2Remedy the faults in the TCM and the CEM first; this code cannot be cleared until those codes have been remedied and erased
- 3Check the connectors and wiring between the transmission control module and the CAN network for open circuits and chafing
- 4After the repair, road test the car and check that the malfunction indicator lamp behaves normally
Symptoms you may notice1
- The check engine lamp lights up or behaves abnormally
General guidance for car owners. Diagnosis on the car can point to a different cause.