What does fault code ECM-P120464 mean?

Diagnostic fault code details for ECM-P120464 (Volvo C30 (2007–2013), Volvo C70 (2006–2013), Volvo C70 (2006–2013)). Repair service at OBD Tuning.

VOLVO

ECM-P120464 - Cylinder #4 Injector Circuit Open/Shorted. Algorithm Based Failures. Signal plausibility failure

System

Engine Control Module (ECM)

Volvo models this fault code applies to

Applies to the following models:

12 models

C30 (2007–2013), C70 (2006–2013), S40 (2004–2013), S60 (2011–), S80 (2007–), V40 (2013–), V40 Cross Country (2013–), V50 (2004–2013), V60 (2011–), V70 (2008–), XC60 (2009–), XC70 (2008–)

Show models by year and engine (40)

What does this fault code mean?

The injector circuit to cylinder 4 has a short circuit. The fault may be in the supply or signal wiring, or be an internal short inside the injector, and the engine control module (ECM) detects it while the engine is running.

Possible causes

Supply wire shorted to ground
Supply wire shorted to voltage
Ground wire shorted to voltage
Signal wire shorted to ground
Signal wire shorted to voltage
Internal short circuit in the injector

What you can do

1Clear the code and road test to see whether it returns
2Use a multimeter to check that the supply and ground wires to cylinder 4 are not shorted to voltage or ground
3Inspect the signal wire to cylinder 4 for chafing and pinching
4Check that the connector at the injector is firmly seated and clean
5If you find no fault in the wiring: have a workshop check the injector

Symptoms you may notice3

Uneven idle
The engine hesitates or surges while driving, either occasionally or all the time
The engine does not start, either occasionally or all the time

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