Codes P0005 and P1431 2004 Cavalier

[csmeutah]

So the wife made it back from Denver (another $900 bucks for a fuel pump) but with a half a tank of cng left it switched over to petrol with a check engine light. The codes read P0005 high pressure fuel shutoff solenoid and P1431 fuel level sensor 2 performance output has not changed for a predetermined amount of time...

Any ideas?

2004 Cavalier, 46K miles--$2400 of repairs in 4 months of ownership and counting.

[siai47]

Re: Codes P0005 and P1431 2004 Cavalier

Most likely P0005 was set as a result of the problem that set P1431. P1431 indicates that the fuel pressure transducer is not changing in output even after several minutes of CNG operation. If the pressure isn't dropping, the ECU senses something is wrong and changes over to gasoline operation, also triggering P0005. A couple of questions- --if you clear the codes and turn the ignition on, (red fuel light off) does the fuel gauge show close to the amount of fuel you think you have in the tank? Can you refill the tank, clear the codes and does the tank show full? Try driving the car after the refill and see if it is running normally. Sometimes the transducers "stick" and refueling might get it indicating again. If you aren't being lucky today, you might have a electrical wiring problem or a transducer failure. There are a couple of voltage checks you can make if necessary if the transducer doesn't start working again on its own. I think this problem has been reported on this forum before.

[csmeutah]

Re: Codes P0005 and P1431 2004 Cavalier

cleared the codes and the problem went away. The wife drove up the canyon and when returning the exact same thing in the same exact spot at the bottom of the canyon. These pressure sensors don't compare to outside/atmospheric pressures do they? Seems like more than just coincidence, we've driven 4K miles since the first occurance.

[siai47]

Re: Codes P0005 and P1431 2004 Cavalier

The computer relies on seeing a change in fuel pressure to make sure you are actually running on CNG and that the proper "map" is being used (gasoline or CNG) because the '03 and '04 Cavaliers use the same engine computer for both fuels. The only thing I can think of is going up the canyon, the car is using fuel at a high rate. This cools the tank and along with the actual fuel usage is going to lower the tank pressure faster then normal. Coming down the canyon, the car is either coasting in fuel cutoff or running at low loads for an extended period of time. This would also allow the temperature in the tank to rise above the temperature reached going up the canyon which may cause the pressure to stop falling or even rise--long enough for the computer to not to see a pressure change and set the code. I am assuming it is a loooong way up and down the canyon .

[Pclement]

Re: Codes P0005 and P1431 2004 Cavalier

I don't know if you feel like you got an answer to your question, but if you're coming down the canyon then you're probably not putting on the gas and coasting mostly. I got this code once on my 04 cav and when I took it in the system was fine, they just told me that it could have been caused by a long coast. Since then that code comes on about once a year. Sometimes I think it comes on after coasting a ways but sometimes just random. Anyway, I invested in an extremely cheap OBDII reader from amazon and just reset it every time. It's going to come back real fast if it's an actual problem, the dealership charged me 100 bucks the first time to tell me nothing was wrong. Anyway, advice is better late than never right?

[csmeutah]

Re: Codes P0005 and P1431 2004 Cavalier

Yeah kind of my experience, got the reader and reset it. If only I could get the wife to reset it...

[Buck]

Re: Codes P0005 and P1431 2004 Cavalier

I have an 04 Cav that sets the P1431 code regularly on long steep highway descents like the Grapevine. We carry a scanner and just clear the code so it's not a big deal. Interestingly the Cav is perfectly fine on twisty descending mountain roads where I'm on and off the pedal more.

[csmeutah]

Re: Codes P0005 and P1431 2004 Cavalier

I had an injector go out and so until I have a solution to that I have disconnected the wires from my cng tank. This worked ok for several months but now I am getting a P0005 error and resetting with the reader doesn't help, it comes back immediately. Assuming this is CNG related, is there a way around this until I get back on CNG so I can get inspected?