VOLVO
ECM-989A - Engine control module (ECM). Signal missing
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS40 (2004–2013), V50 (2004–2013)
Show models by year and engine (2)
What does this fault code mean?
Although the code is named signal missing, it concerns the module's internal voltage references, the reference voltages the module uses for its own measurements. The code is set when the module detects a fault in them, which points to the module itself rather than to a sensor.
Possible causes
- Damaged engine control module (ECM)
What you can do
- 1Read the code, clear it and start the engine to see whether it returns
- 2Check that the battery is in good condition and that the engine control module connectors are fully seated
- 3If the fault returns after clearing, the module is damaged and should be replaced; leave this to a workshop
Symptoms you may notice1
- Malfunction indicator lamp (MIL) is on
General guidance for car owners. Diagnosis on the car can point to a different cause.