P2A46 code meaning
Alternative Fuel Tank C Pressure Sensor Circuit
Powertrain system Generic code P2Axx codes Check engine light
What P2A46 means
Larger CNG installations, for instance on trucks or buses, may carry three or more cylinders. Where a third one, tank C, has its own pressure transducer, P2A46 reports a general electrical fault in that sensor's circuit, stored when the module finds the signal unusable but cannot classify it as too low or too high. Publicly described is only the single tank sensor of simpler systems: Ford placed it inside the regulator of its 2003 bi-fuel CNG pickups and let the AFCM derive the gauge reading from it. No manufacturer lists P2A46. In practice the first checks are the three wires at the tank C sensor, the connector seal and the shared 5 V feed; the narrower codes P2A48 and P2A49 name a low or high signal, P2A4A short interruptions.
P2A46 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2A46
- Check engine light
- Remaining gas shown wrongly
- Tank C may be left unused
Common causes of P2A46
- Most likelyWiring or plug at the tank C sensor damaged, loose or wet
- PossibleTank C pressure sensor faulty
- Less likelyShared 5 V supply or sensor ground disturbed
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 P2A46 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. |
| 46 | The exact fault in that area. |
What to do next
- Note P2A46 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 P2A46
What does P2A46 mean?
P2A46 means "Alternative Fuel Tank C Pressure Sensor Circuit". Larger CNG installations, for instance on trucks or buses, may carry three or more cylinders. It is a generic code, so it means the same on every make.
Is it safe to drive with P2A46?
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 P2A46 fail an emissions test?
Yes, it can. P2A46 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 P2A46 to fix?
Difficulty: hard. A typical repair takes 1 to 3 hours of work. This is a job for a workshop.
Will P2A46 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.