VOLVO
ECM-851D - 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) follows the internal supply circuits to the sensors and sets the code when the voltage in one circuit is too low. The check runs with the ignition on. If another code for a sensor on the same supply is stored, it should be traced first, since it may be the cause.
Possible causes
- The supply wire to the sensor is shorted to ground
- The sensor is damaged
- The control module is damaged
What you can do
- 1Trace first any codes for sensors fed from the same supply, since they may be the cause
- 2Read the code, clear it and road test the car to see whether it comes back
- 3Use a multimeter to check that the supply wire to the sensors has no contact with ground (the body)
- 4Check the sensor connectors for oxidation and loose fit
- 5If the code remains after these checks, have a workshop decide whether the control module needs replacing
Symptoms you may notice2
- The starter motor does not turn
- The engine is hard to start
General guidance for car owners. Diagnosis on the car can point to a different cause.