VOLVO
ECM-1794 - Battery voltage. 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 ECM monitors the battery voltage. If the voltage is out of range, high or low, fault code ECM-1794 is set. The fault may lie in the battery or in the alternator.
Possible causes
- Damaged battery
- Damaged alternator
What you can do
- 1Check that the battery terminals are tight and clean, and that the connectors in the battery circuit have no play or oxidation
- 2Check the condition of the battery. An old or flat battery can give the wrong voltage, so charge or replace it as needed
- 3If you have a diagnostic tool: read the battery voltage in live data with the engine off and running, and check that the values look reasonable
- 4If the fault remains after these checks, have a workshop check that the alternator charges correctly
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.