VOLVO
ECM-P120429 - Cylinder #4 Injector Circuit Open/Shorted. General Signal Failures. Signal signal invalid
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS80 (2007–), V70 (2008–)
Show models by year and engine (2)
What does this fault code mean?
The code for cylinder 4 is set when the engine control module (ECM) sees that the signal to the injector is too high, too low or otherwise faulty. The cause may be poor contact, or a short or open circuit in the wiring.
Possible causes
- Contact resistance or oxidation in the connections
- Short circuit or open circuit on the wires to the injector
What you can do
- 1Read the code and note that it applies to cylinder 4
- 2Check that the connector at injector cylinder 4 is firmly seated and free from oxidation
- 3Inspect the wire to cylinder 4 for chafing, pinching and breaks
- 4If you have a diagnostic tool: activate the injector for cylinder 4 and listen for it operating
- 5If you find no fault: have a workshop check the injector
Symptoms you may notice3
- The engine stalls on start
- A clicking sound, or no sound at all, when starting is attempted
- Poor performance and lack of power while driving
What the fault can affect1
- Injection stops
General guidance for car owners. Diagnosis on the car can point to a different cause.