VOLVO
ECM-987A - Engine control module (ECM). Internal fault
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?
The module has detected an internal fault in its own analogue-to-digital conversion, the stage that turns sensor signals into values it can calculate with. Because the fault lies inside the module itself rather than in a sensor, the module is the likely cause. While the fault is present the engine may limit speed and torque to a calculated normal value.
Possible causes
- Damaged engine control module (ECM)
What you can do
- 1Read the code, clear it and road test the car to see whether it returns
- 2Check that the battery is in good condition and that the engine control module connectors are fully seated and free from oxidation
- 3If the fault returns after the road test, the module is probably damaged and should be replaced; leave this to a workshop
Symptoms you may notice4
- Maximum engine speed is lower than normal
- Cruise control does not work at all
- Uneven idle
- Malfunction indicator lamp (MIL) is on
What the fault can affect1
- Engine speed and torque are capped at a level the module calculates as normal
General guidance for car owners. Diagnosis on the car can point to a different cause.