VOLVO
ECM-P120129 - Cylinder #1 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 engine control module (ECM) follows the signal to injector cylinder 1 and how the valve works. The code is set when that signal is too high, too low or otherwise faulty.
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 and note the code, clear it and road test to see whether it returns
- 2Check that the fuses are intact
- 3Check the connector to injector cylinder 1 for contact resistance and oxidation
- 4Inspect the wires to the injector for chafing, pinching and breaks
- 5If you have a diagnostic tool: activate injector cylinder 1 and check that it operates
- 6If you find no fault: have a workshop check the injector
Symptoms you may notice4
- Poor performance and lack of power while driving
- The engine stalls on start
- The engine does not start or does not crank, either occasionally or all the time
- A clicking sound, or no sound at all, when starting is attempted
What the fault can affect1
- Injection stops
General guidance for car owners. Diagnosis on the car can point to a different cause.