VOLVO
ECM-P251900 - A/C Request A Circuit. General Failure Information. No sub type information
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
3 modelsS60 (2011–), S80 (2007–), V70 (2008–)
Show models by year and engine (9)
- Volvo S60 (2011–)2011–2012Engine B5254T5 only
- Volvo S80 (2007–)2007–2008Engine B5254T6 only
- Volvo S80 (2007–)2009Engine B5254T6, B5254T8 only
- Volvo S80 (2007–)2010–2011Engine B5254T10, B5254T11, B5254T8 only
- Volvo S80 (2007–)2012Engine B5254T10 only
- Volvo V70 (2008–)2008Engine B5254T6 only
- Volvo V70 (2008–)2009Engine B5254T6, B5254T8 only
- Volvo V70 (2008–)2010–2011Engine B5254T10, B5254T11 only
- Volvo V70 (2008–)2012Engine B5254T10 only
What does this fault code mean?
The engine control module sets the stroke volume of the A/C compressor through a control valve (solenoid) driven by a PWM signal. The code is checked when A/C is switched on, and it is stored when the signal from the control valve is outside the limits the control module uses. This may be due to a short in the signal wire, an open circuit in the supply wire or a damaged control valve.
Possible causes
- Signal cable shorted to supply voltage
- Signal cable short-circuited to ground
- Open circuit in the voltage supply cable
- Damaged control valve (solenoid)
What you can do
- 1If you have a diagnostic tool, activate the A/C compressor and read the control valve drive signal in live data
- 2Check that the relevant fuses are intact
- 3Check the connector to the control valve in the A/C compressor for contact resistance and oxidation
- 4Use a multimeter to check that the signal wire to the control valve has no open circuit and is not short-circuited to plus or to ground (body)
- 5If the fault remains, have a workshop with diagnostic equipment check the control valve in the A/C compressor
Symptoms you may notice1
- Uneven cooling from the A/C system
General guidance for car owners. Diagnosis on the car can point to a different cause.