Powertrain, generic (extended)

P2543 Low Pressure Fuel System Sensor Circuit Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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 Other manufacturers do not publish thresholds for this code.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.

Likely causes

Loose or corroded pin at the sensor connector
Chafed signal or supply wire with intermittent contact
Outdated engine software (manufacturer update available)

Symptoms

  • Check engine light, often intermittent
  • Brief stumbling or hesitation
  • No symptoms between events

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–300
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

low pressure fuel sensorsensor wiring

Related codes

P2539P2540P2541P2542

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov.