VOLVO
ECM-850D - 5 volt power supply. 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?
The engine control module (ECM) monitors the internal voltage circuits that feed the components and sets the code when the voltage in one circuit is too low. The check runs with the ignition on. The cause may be a short to ground in the wire, a damaged sensor or a damaged control module.
Possible causes
- Voltage cable to a sensor shorted to ground
- Damaged sensor
- Damaged control module
What you can do
- 1Read the code, clear it and check that it is not active after the road test
- 2Check the sensor voltage cable for chafing and contact with ground; use a multimeter to confirm the cable has no contact with the body
- 3Check that the sensor connectors are fully engaged and free from oxidation
- 4If you have diagnostic equipment, read the sensor values in live data with the ignition on and see whether any one gives a too-low reading
- 5If the code remains after these checks, have a workshop decide whether the control module needs replacing
Symptoms you may notice3
- The starter motor does not turn
- The starter cranks but the engine will not start
- Poor performance
General guidance for car owners. Diagnosis on the car can point to a different cause.