P2147: Fuel Injector Group A Supply Voltage Circuit Low
Do not keep driving
Expect a severe misfire or a no-start. Ask for each injector in the affected group to be measured individually — one internally shorted injector drags the whole group's supply down and looks exactly like a module fault.
What this code means
The group A injector supply reads below what it should be. On a boosted-rail system that means the module is not producing its elevated voltage, or something is loading it down.
An injector winding that has shorted internally is the classic loader. It pulls the shared rail down for the whole group, so every injector on that supply is starved and the module reports the supply rather than the injector. Measuring each winding in the group individually is what finds the culprit — and it is worth doing before any conclusion about the module, because one cheap injector can produce this picture.
Likely causes
Start here
- Short circuit in a fuel injector · moderate
- Wiring shorted to ground · moderate
- Faulty fuel injector control module · specialist
Less common
- Damaged injector wiring harness · moderate
- Low system voltage · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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