VOLVO
ECM-999D - Engine control module (ECM). Signal too low
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
4 modelsC30 (2007–2013), C70 (2006–2013), S40 (2004–2013), V50 (2004–2013)
Show models by year and engine (9)
- Volvo C30 (2007–2013)2007Engine B5254T3 only
- Volvo C30 (2007–2013)2008–2013Engine B5254T7 only
- Volvo C70 (2006–2013)2006–2007Engine B5254T3 only
- Volvo C70 (2006–2013)2008–2013Engine B5254T7 only
- Volvo S40 (2004–2013)2005–2007Engine B5254T3 only
- Volvo S40 (2004–2013)2008Engine B5254T3, B5254T7 only
- Volvo S40 (2004–2013)2009–2012Engine B5254T7 only
- Volvo V50 (2004–2013)2005–2007Engine B5254T3 only
- Volvo V50 (2004–2013)2008–2012Engine B5254T7 only
What does this fault code mean?
Despite the name signal too low, the code concerns the engine control module's own restart function. The module monitors this function continuously, and the code is set when a fault occurs in it. The fault therefore lies in the module, and when it tries to restart itself the engine may stall or fail to start altogether.
Possible causes
- Software in the module is faulty
- Damaged module
What you can do
- 1Read the code, clear it and start the engine to see whether it returns
- 2Check that the battery terminals and the module connectors are fully seated and free from oxidation
- 3If the fault remains, a workshop should try new software in the module
- 4If the new software does not help, the module is damaged and must be replaced; both replacing and programming it is a job for a workshop
Symptoms you may notice4
- Malfunction indicator lamp (MIL) is on
- Malfunction indicator lamp (MIL) flashes
- The engine stalls
- The engine cranks but will not start
What the fault can affect1
- The engine control module tries to restart itself
General guidance for car owners. Diagnosis on the car can point to a different cause.