What does fault code ECM-P251919 mean?

Diagnostic fault code details for ECM-P251919 (Volvo S80 (2007–), Volvo V70 (2008–), Volvo XC60 (2009–)). Repair service at OBD Tuning.

VOLVO

ECM-P251919 - A/C Request A Circuit. General Electrical Failures. Over temperature

System

Engine Control Module (ECM)

Volvo models this fault code applies to

Applies to the following models:

5 models

S80 (2007–), V70 (2008–), XC60 (2009–), XC70 (2008–), XC90 (2003–)

Show models by year and engine (6)

What does this fault code mean?

Although the code is named over temperature, it concerns a fault on the output of the internal power stage in the engine control module, which drives the A/C compressor solenoid with a PWM signal. The code can be checked when A/C is activated.

Possible causes

Signal line from the engine control module short-circuited to supply voltage (see ECM-P252112)
Damaged solenoid in the A/C compressor
Signal line from the engine control module short-circuited to ground (see ECM-P252011)
Contact resistance or oxidation in the connectors, or open circuit in the signal line (see ECM-P251913)
Internal fault in the engine control module

What you can do

1Read the fault status while A/C is on and the engine is running. If the fault is not visible, it may have been intermittent
2Check that the relevant fuses are intact
3If you have a diagnostic tool, activate the A/C compressor and see whether it responds to the control
4Use a multimeter to check that the signal line from the engine control module to the A/C compressor is not short-circuited to supply voltage or ground
5If the fault returns, have a workshop assess whether the engine control module needs replacing, since an internal fault cannot be remedied by the owner

Symptoms you may notice1

No cooling effect from the A/C system

General guidance for car owners. Diagnosis on the car can point to a different cause.