No Obdii Codes - Check Engine Light Is On

[azswede1960]

I went to two different places to hook up different scanners, and DO NOT get any codes or any indication that my OBD connection is working! I was told there is an OBD fuse, but I don't know which one that is ..... or if there is something else I need to check.

 

Can anyone help, I have CHECK ENGINE LIGHT "ON" ........

[Draenor]

Same fuse for the cig. lighter.

[azswede1960]

Same fuse for the cig. lighter.

[NothinButBowTies]

The weird thing is that there is no way of knowing the fuse is blown. I never have anything plugged into my 12v, but it turns out the fuse was blown. Same thing happened to me with a MIL light and no code retrival.

[Norseman]

After you check to see if there is power at the port, another consideration would be that the code is GM specific and you have to get access to a reader that can get those type codes.

[azswede1960]

I just checked & my cigarette lighter was broken I fixed it and am going back to check the codes!

[azswede1960]

All fixed and scanner can now communicate with computer:

 

Code is P0442 Evap Emission Control System Leak (small) ....

 

Now what?

 

Anything to do with putting a K&N filter on my truck a couple of weeks ago??????

[Rocco715]

All fixed and scanner can now communicate with computer:

 

Code is P0442 Evap Emission Control System Leak (small) ....

 

Now what?

 

Anything to do with putting a K&N filter on my truck a couple of weeks ago??????

 

 

I doubt its the K&N, Check your gas cap first put on then take it off. If it's not that then go to a shop and have them run smoke through the lines to find the leak. You could have a leaking hose that attaches to the charcoal canister.

[ballon78]

make sure all fuel hoses are tight(filler neck) gas cap has a good oring on cap, look for leaking fuel stains on tank...i once had a fuel leak where the fuel pump bolts to the tank, the oring was bad and there was rust around it. There is a prge solinoid too that i have seen stick open on another vehical i had, if you find nothing then smoke test like ROCCO717 said......hope that helps.

[azswede1960]

make sure all fuel hoses are tight(filler neck) gas cap has a good oring on cap, look for leaking fuel stains on tank...i once had a fuel leak where the fuel pump bolts to the tank, the oring was bad and there was rust around it. There is a prge solinoid too that i have seen stick open on another vehical i had, if you find nothing then smoke test like ROCCO717 said......hope that helps.

 

Checked them all - cap looks good and I tightened it good. Will clear code today (have not done it yet) as I was wondering, IF it was for example a loose gas cap, and it got tightened to where leak was no more: WOULD CHECK ENGINE LIGHT go out by itself, and how long would one expect to wait for that to happen? OR does one HAVE to clear the code manually????