P023FFuel Pump Secondary Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- The fuel pump circuit has two sides: the primary circuit is the engine module's output to the fuel pump relay coil (or to a pump control module), the secondary circuit is the power circuit from relay contact or module to the pump itself. P023F means the power circuit to the pump is open. GM pumps with their own power module, whose speed is controlled by rail pressure, measure the pump current: if it stays below 1 A (older modules 0.5 A) although the pump is commanded, the code sets with the warning light in the first trip, and fuel pressure diagnostics are suspended. The cause lies in the wire from module to pump or its return, the pump connector or the pump motor itself. The pump stops, so the engine will not start or dies – there is no limp mode.
- What you may notice
- Engine does not start, no pump noise
- Engine stalls while driving
- Check engine light on
- Likely causes
- LikelyPump connector at tank flange or pump module open or corroded
- LikelyFuel pump open internally (brushes, winding)
- PossibleWire from module to pump or return wire open
- RarePump control module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.