Not my Vette but....

[Kap142]

Need a little help gang. My 02 TrailBlazer had the check engine light come on yesterday. Local auto parts store and the mini computer showed a code of P0440 with a read out saying EVAP emission control system but provided no other info. Kinda feels like an O2 sensor to me but I believe their are four of them. Any way with what I've provided can the actual part needing replacement can be identified? And then how do you reset the durn check engine light?

[gmjunkie]

Originally Posted by Kap142

Need a little help gang. My 02 TrailBlazer had the check engine light come on yesterday. Local auto parts store and the mini computer showed a code of P0440 with a read out saying EVAP emission control system but provided no other info. Kinda feels like an O2 sensor to me but I believe their are four of them. Any way with what I've provided can the actual part needing replacement can be identified? And then how do you reset the durn check engine light?

Ken,Check the gas cap,and also the lines to the charcoal canister for the Evap system!!I believe the canister is behind the left rear wheel up behind the bumper!! I'll check in the SI program on my computer!! Fix the Evap system,and the light will go out on it's own in a short amount of time!!

This code P0440 is usually is a Loose Gas Cap or Broken Hose Connection in the back,But I have seen'm where a chunk of road deb're damaged the lines under the vehicle going to the back!!!!

[Kap142]

Junk you're awesome. Durn gas cap was loose! Thanks for the help.

Ken

[Curacao]

IF you just filled the fuel tank. Check your gas cap.

Info from GM eSI.

Adm Msg -- P0440 Caused By Gas Cap Not Being Tightened After Fuel Fill
2002-2003 Chevrolet TrailBlazer

Equipped with LL8 4.2L Engine or LM7 5.3L Engine

Service Manager

Some customers may comment about a Check Engine light with a P0440 series DTC indicating that an evaporative emission leak has been detected. After reviewing the warranty data and making dealer callbacks, General Motors Service Operations has found that a very high percentage of these DTCs are caused by the gas cap not being completely tightened after a fuel fill. There is no known issue with gas cap retention. Therefore, if a dealer should get a vehicle in with this failure, and after running through the SI diagnosis no other trouble is found, please ensure that the gas cap is tight. Instruct the customer that this issue may have been caused by the cap not being tightened after the last fill up. In addition, to ensure that customers do not experience a similar incident with the first 200 miles of ownership, please ensure that the technicians performing the PDI or initial tank fill up at your dealership are tightening the gas cap completely. To make sure the gas cap is secured completely, you must hear at least 3 clicks.


Important
If the PCM is completing the EVAP diagnostic, filling of the fuel tank cannot be completed as the vent valve will be closed and the fuel dispenser nozzle will sense the pressure build-up and shut down. This is the expected result. No parts should be replaced as nothing is faulty. To keep from encountering this situation, it is imperative all customers and dealership personnel be advised NOT TO FILL THE FUEL TANK WITH THE ENGINE RUNNING. If the condition is encountered, turn the ignition to the OFF position for a minute. This will allow the PCM to go to sleep completely, thereby opening the vent valve.

[gmjunkie]

Originally Posted by Kap142

Junk you're awesome. Durn gas cap was loose! Thanks for the help.

Ken

Thanks Ken,No Problem!!I hear where we are going to a Mutual Friends wedding!!See you there if I don't make it to the BBQ!!

[Kap142]

Originally Posted by gmjunkie

Thanks Ken,No Problem!!I hear where we are going to a Mutual Friends wedding!!See you there if I don't make it to the BBQ!!

Yes we are and it ought to be fun. They're neat people.

Hope you can join us for the Bar B Q and again, thanks. It's almost neat when it's something that doesn't cost an arm and a leg (loose gas cap).

Stay well.

Ken

["Backyard Mechanic"]

Originally Posted by Kap142

Junk you're awesome. Durn gas cap was loose! Thanks for the help.

Ken

Been there done that

[LS2POWA]

This must be a common thing for GM vehicles. My moms 04 Impala has gone in twice for two new gas caps at the local dealer...the third time she went to auto zone and bought a universal one, error hasn't come back ever since. Maybe thats another reason they are hurting....