VOLVO
ECM-A690 - 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 its link with the transmission control module (TCM). The code is set when the TCM requests that the malfunction indicator lamp be lit, which is treated as a faulty signal, and also when that signal cannot be seen on the CAN network. The fault therefore most likely lies with the TCM.
Possible causes
- A fault in the transmission control module (TCM)
- The signal from the transmission control module is missing from the CAN network
What you can do
- 1Read the TCM fault codes first, then the CEM codes
- 2Remedy the TCM faults and the CAN-related codes in the CEM first; clear this code once they are gone
- 3Check that the connectors to the transmission control module are fully seated and free from oxidation
- 4After the repair, road test the car and see whether the malfunction indicator lamp comes on again
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.