P2543Low Pressure Fuel System Sensor Circuit Intermittent
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2543 reports a low-pressure fuel sensor signal with brief interruptions or spikes, although it remains within its electrical range most of the time - a loose pin, a chafed wire or a sensor with an internal contact problem. Ram names P2543-00 for trucks with the 6.7 L Cummins HO in two PCM software bulletins, 18-013-26 (Ram 2500) and 18-021-25 (Ram 3500), each covering model year 2025 and each listing it next to P2540-00. Flawed calibration can therefore also produce entries. Other manufacturers do not publish thresholds for this code. CARB requires input components to be checked for circuit faults and, where feasible, rationality. P2541/P2542 describe a steady low or high signal, P2540 a plausibility fault. The code often comes and goes, sometimes with brief stumbling.
- What you may notice
- Check engine light, often intermittent
- Brief stumbling or hesitation
- No symptoms between events
- Likely causes
- LikelyLoose or corroded pin at the sensor connector
- PossibleChafed signal or supply wire with intermittent contact
- RareOutdated engine software (manufacturer update available)
- 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: €40 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.