P2543 code meaning
Low Pressure Fuel System Sensor Circuit Intermittent
Powertrain system Generic code P25xx codes Check engine light
What P2543 means
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 Other manufacturers do not publish thresholds for this code.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.
P2543 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2543
- Check engine light, often intermittent
- Brief stumbling or hesitation
- No symptoms between events
Common causes of P2543
- Most likelyLoose or corroded pin at the sensor connector
- PossibleChafed signal or supply wire with intermittent contact
- Less likelyOutdated engine software (manufacturer update available)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Low pressure fuel sensorSensor wiring
What each part of P2543 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| 43 | The exact fault in that area. |
What to do next
- Note P2543 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2543
What does P2543 mean?
P2543 means "Low Pressure Fuel System Sensor Circuit Intermittent". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2543?
Drive gently and only to a workshop. With P2543 the car can go into limp mode (reduced power) to protect itself.
Will P2543 fail an emissions test?
Yes, it can. P2543 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2543 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2543 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.