What it means
The AFCM detects a generic fault on the pressure sensor of alternative fuel tank B. Tank pressure cannot be monitored reliably.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
The AFCM uses the pressure sensor on alternative-fuel tank B to monitor pressure in that tank. P2A41 indicates a general fault that makes the tank B pressure reading unreliable; it does not by itself specify whether the signal is too high, too low, or intermittent. The module may limit alternative-fuel operation when it cannot trust this measurement.
Common causes
Most likely first.
- Pressure sensor failed
- Wiring or connector fault
Symptoms
- Check-engine light
- Alternative-fuel warning light
- Inaccurate tank pressure or fuel-level indication
How to diagnose it
- Save freeze-frame data and read AFCM live data for tank B pressure, warning status, and any related alternative-fuel codes.
- Check the tank B pressure reading against the vehicle’s current fuel and temperature conditions for an obviously implausible or missing value.
- Inspect the tank B sensor connector and harness for corrosion, loose pins, damage, or poor routing.
- Check the sensor power, ground, and signal circuits using the manufacturer’s wiring diagram and specifications.
- If the wiring tests pass, test the tank B pressure sensor and its mounting according to the manufacturer’s procedure.
Common fixes
- Secure the tank B pressure-sensor connector or repair damaged wiring.
- Clean or repair corroded connector terminals and restore good contact.
- Replace the tank B pressure sensor if it fails the specified circuit tests.
- Correct a loose sensor mounting if it is preventing a reliable reading.
Can I keep driving?
The alternative-fuel warning and inaccurate tank information mean you should not rely on the tank B pressure or fuel indication. If gasoline operation is normal, use it only as needed while arranging diagnosis; stop if the vehicle loses power or shows signs of a fuel leak.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.