The GAS CAP code!!!!!!!!!!!!!!

[j cAT]

Originally Posted by tamabear

the truck is clean no rust and only has 70000 miles on it and has never had the tank massed with we went thru all the lines and no cracks or pinched hoses and didn't find any rusted out lines out of things to look at thanks anyway...

if you did check all these things I mentioned then my guess is the in tank fuel pump assembly pressure/vacuum sensor. this is part of the fuel pump unit.

If you have only this dtc p0442 then this is why I say this part.

the dealership if they have people that know what there doing should be able to test this component for proper operation rather than parts replacing at your expense.

your issue is a very small leak not pinched hoses or valves stuck open or plugged up.. this sensor maybe failing when sensing the vacuum.


looks like the 2009 has issues with this ..service bulletin is this
SB-10-06-04-001 01/01/2010
10034369
2010-11-08
Chevrolet/gmc/pontiac: intermittent mil/check engine light on, dtc p0442, p0446, p0451, p0452, p0453, p0454 or p0455 (install fuel tank pressure sensor cover). this condition may be caused by normal water accumulation or condensation bloc

[Tech II]

Needs to be smoked tested by someone who knows what they are doing....

[Simulacrum dwp]

Short version 2012 Impala 100000 miles brought to dealership for repairs involving fuel gauge failure. Pick up car drove aprox 3 miles and got tighten gas cap message. Tighten cap everything seemed fine, two days later got second tighten gas cap message, checked cap everything seemed okay ,started car and now have engine light. Car is at dealership for diagnostic , so no code yet. Trying to determine what the dealership could have screwed up to cause code. Should note that this is second time car has been returned to dealership because of sloppy work ( also had problem with airbag light after engine repair that was done at same time)

[Tech II]

Obviously, if the code was not there before, it's possible they caused it.....

Do you know exactly what was done? Was fuel sender replaced?

[Simulacrum dwp]

From the invoice, Internal faultwith fuel level sensor replaced faulty fuel level sensor

[Simulacrum dwp]

No problems prior to repairs Car rn ojt of gas due to level sensor notvreading correctly

[Simulacrum dwp]

Update code appears to be evap solenoid failure claim is it is coincidental to fuel level issue . Supposedly fuel level issue was masking. Solenoid problem. Doe this sou d probable or is the dealership jerking me around. Honestly my gut feeling is this is B.S. so any opinion would be appreciated.

[j cAT]

Originally Posted by Simulacrum dwp

Update code appears to be evap solenoid failure claim is it is coincidental to fuel level issue . Supposedly fuel level issue was masking. Solenoid problem. Doe this sou d probable or is the dealership jerking me around. Honestly my gut feeling is this is B.S. so any opinion would be appreciated.

they F'ed up the fuel tank venting system it is a leak a large leak they damaged the lines going to the fuel tank or they damaged the charcoal canister/ lines to that as well .. I am sure they WILL NOT reveal what the did improperly .

If they screw with you about this ,, post the dealerships name and how they screwed you .. also facebook ..

[Tech II]

Update code appears to be evap solenoid failure claim is it is coincidental to fuel level issue . Supposedly fuel level issue was masking. Solenoid problem. Doe this sou d probable or is the dealership jerking me around. Honestly my gut feeling is this is B.S. so any opinion would be appreciated.

Fuel level sensor has nothing to do with the evap solenoid, and vice versa.....

The reason why I asked if the level sender was replaced, was because that means the evap system was opened, and this could cause a leak, possibly at the evap line, or more likely the o-ring between the gas tank and the fuel module was possibly pinched......

[Simulacrum dwp]

Tahnk for the imput. Pick car up today no further repairs done was quoted a price of $98 to replace inoperative evap vent solenoid. Told them I would get back to them about it. Asked what the code was and was told it was P0442 code. When I got the car back engine light was still on. I planned on bringing the car to an auto parts store to see if they could run code. Drove about 6-7 miles stopped at a different store for amoment and when I started the car again engine light was off. Engine light has stayed off and remote start is working again.

[Tech II]

P0442 is not a solenoid code....it means there is a small leak somewhere in the entire system......

It could be the solenoid, if the solenoid is not sealing when turned off........

Coincidence that it failed(located on top front of engine) when working on the gas tank? Who knows?

but like I said, if there was no P0442 set before the work was done, chances are the leak is where they took the evap system apart, at the gas tank...

Fact they said, " Supposedly fuel level issue was masking. Solenoid problem." is total crap.....

If you have a small evap leak, the only sure way to find it, is to seal the system with a TECH II scan tool, and pressurize the system with a smoke machine.....where you see smoke, you find the leak....

[j cAT]

the dealership created a leak in the fuel tank seal or the lines. dropping the fuel tank the charcoal canister can get cracked .

the 442 code could be a bad valve .. the fuel level if not between the 1/4-3/4 range the fuel evap system test will not be taken by the PCM .

block seal the line going to the evap vent valve see if you still get the 442 code.. I would check out the lines under there as you do this ..

449/446 codes are the ones most times indicating the vent valve the problem ...

leaks could also the the fuel fill pipe .. I did have that happen .. used some metal mender or marine-tex epoxy .. rust hole up on the pipe support flange ..

[j cAT]

[quote=Simulacrum dwp;7206665]Tahnk for the imput. Pick car up today no further repairs done was quoted a price of $98 to replace inoperative evap vent solenoid. Told them I would get back to them about it. Asked what the code was and was told it was P0442 code. When I got the car back engine light was still on. I planned on bringing the car to an auto parts store to see if they could run code. Drove about 6-7 miles stopped at a different store for a moment and when I started the car again engine light was off. Engine light has stayed off and remote start is working again.[quote] ---------------------------------------------------------------------------------






could be the very cold temps caused the light to come on . the seal on the fuel tank may have seated properly stopping the small leak.

[Simulacrum dwp]

Ok so here is where I'm at now. Light came back yesterday afternoon. A friend who has a diagnostic checked it out and there is two codes P0443 and P0455. I am planning on contacted GM regarding this ( considering it was their dealship and mechanics that did the work incorrectly) any further advice would bve appreciated.

[Tech II]

Both codes have to do with the purge valve or it's circuit.....

Simple way to check a purge valve, disconnect wire harness to purge valve, apply vac(use vac pump) to the end of the valve that goes to the evap system(not the end that goes to the intake)......vac should hold......now apply 12 volts and ground to valve(pink wire is usually the hot wire), and the valve will open and the vac will drop....

What usually happens is the vac doesn't hold and it leaks......or the solenoid does not open to purge the system when powered....