P2A47 code meaning
Alternative Fuel Tank C Pressure Sensor Range/Performance
Powertrain system Generic code P2Axx codes Check engine light
What P2A47 means
P2A47 is not about broken wires: the tank C sensor delivers a voltage inside its window, yet the pressure it reports cannot be true. Plausible tests are a value that stays flat while the engine draws gas from tank C, one that does not rise during filling, or a clear gap to tanks A and B after a long rest, since cylinders on a common fill manifold settle to similar pressure. For scale, the bulletin SMB-169 that New Flyer issued for CNG buses expects the high-pressure gauge to read somewhere from 200 psi to 3,600 psi after refuelling. The cause can also be mechanical, such as a tank C valve that never opens (P2A27) or a closed manual valve. No manufacturer publishes P2A47 or its thresholds; CARB demands rationality monitoring of such inputs. Compare with a calibrated gauge before replacing parts.
P2A47 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P2A47
- Check engine light
- Gas level shown does not match refuelling or consumption
- Shorter driving range on gas
Common causes of P2A47
- Most likelyTank C sensor drifted or frozen at one value
- PossibleTank C solenoid not opening or manual valve closed
- Less likelyCorroded contacts shifting the signal
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Alt fuel tank c pressure sensorWiring harnessAfcm
What each part of P2A47 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| A | Area: hybrid propulsion. |
| 47 | The exact fault in that area. |
What to do next
- Note P2A47 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 P2A47
What does P2A47 mean?
P2A47 means "Alternative Fuel Tank C Pressure Sensor Range/Performance". P2A47 is not about broken wires: the tank C sensor delivers a voltage inside its window, yet the pressure it reports cannot be true. It is a generic code, so it means the same on every make.
Is it safe to drive with P2A47?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2A47 fail an emissions test?
Yes, it can. P2A47 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 P2A47 to fix?
Difficulty: hard. A typical repair takes 1 to 3 hours of work. This is a job for a workshop.
Will P2A47 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.