P2147Fuel Injector Group A Supply Voltage Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2147 means the common feed of injector group A is pulled toward ground. GM documents it in detail for its 2018 Duramax diesels: the high-side line to injectors 1 and 4 (group 1 on both the 2.8 L four and the 6.6 L V8) shows 0.5 Ω or less to ground while the driver is switched on; with the engine running and more than 11 V, 5 failures in 10 samples at 100 ms set it, type A, lamp on the first trip (2025 tables: 4 of 8). Ford's 2023 diesels report a short of group A to ground or battery found by the driver chip after about 0.2 s. On GM petrol direct injection such as the Saab 9-5 2.0T the code stands for low voltage on the high-side control line of cylinder 1. Both injectors of the group usually stop, so two cylinders drop out. P2148 is the opposite fault.
- What you may notice
- Two cylinders misfire at once
- Heavy loss of power, rough running
- Check engine lamp on immediately
- Likely causes
- LikelyInjector supply wire chafed and shorted to ground
- PossibleInjector of the group shorted internally to its body
- PossibleWater in the injector harness connector
- RareFaulty injector driver in the engine control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.