VOLVO
ECM-A680 - Transmission control module (TCM). Faulty signal
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 engine control module monitors CAN traffic between itself and the transmission control module (TCM). The code is set in two ways: when the TCM asks for the malfunction indicator lamp to flash, which counts as a faulty signal, or when that lamp signal is absent from the CAN network. Either way, the fault most likely lies in the transmission control module.
Possible causes
- The TCM sends a request for the malfunction indicator lamp to flash
- The lamp signal from the transmission control module is absent from the CAN network
What you can do
- 1Read the fault codes in the transmission control module (TCM) first, then in the central electronic module (CEM)
- 2Fault-trace and remedy the TCM faults and the CAN codes in the CEM before clearing this code
- 3Check the connectors and CAN wiring to the transmission control module for open circuits and chafing
- 4Clear the fault code once the faults are remedied and road test the car to see whether it returns
Symptoms you may notice1
- No noticeable symptoms for the driver
General guidance for car owners. Diagnosis on the car can point to a different cause.