Some multi-tank CNG installations give a second cylinder, tank B, its own pressure transducer, so the module knows the remaining gas per tank and can check that the tank valve responds. P2A41 is the general electrical fault of that sensor, set when the circuit is faulty without a clear verdict of low or high. Publications only describe the single sensor of tank A: on Ford's 2003 bi-fuel CNG trucks it is built into the regulator and drives the gauge, which the AFCM forces to empty when the sensor fails. The upfitter TransEco substitutes a fixed 3600 psi and keeps running. No manufacturer lists P2A41. Check the 5 V feed, signal and ground at the tank B sensor plug first; P2A43 and P2A44 separate the low and high cases, P2A45 brief dropouts.
High severity. Can I keep driving?If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.
Symptoms
- Check engine light
- Gas gauge wrong or showing empty
- Tank B possibly no longer used
Most likely causes
- Plug at the tank B sensor loose, corroded or harness damaged
- Tank B pressure sensor faulty
- 5 V reference or sensor ground disturbed
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It affects emissions.
What each character of P2A41 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- A: Hybrid or air and fuel
- 41: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2A41?
If you smell gas, do not keep driving or start the engine: move away and call for assistance. With no smell, drive moderately to an authorized shop.
What causes code P2A41?
The most common causes are: plug at the tank B sensor loose, corroded or harness damaged; tank B pressure sensor faulty; 5 V reference or sensor ground disturbed.
Related codes
- P2A42Alternative Fuel Tank B Pressure Sensor Range/Performance
- P2A43Alternative Fuel Tank B Pressure Sensor Circuit Low
- P2A44Alternative Fuel Tank B Pressure Sensor Circuit High
- P2A45Alternative Fuel Tank B Pressure Sensor Circuit Intermittent/Erratic
- P019EAlternative Fuel Tank A Pressure Sensor Circuit
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.