CEL Comes and Goes

[Russ in California]

The CEL came on on the first day of my Steens Trip in July. Went away and didn't come back on till a week or so ago. It's been on and off, mostly off. Tried to pull the code with the little wire thingy but CEL no flashy. Started the beast up and the CEL isn't on. I thought the code might be stored but maybe I can only pull the code if the CEL is actually on. Does this sound right?
I haven't purchased a FSM yet nor do I have an actual code reader. I thought the jump wire would do the trick. Guess I'll try again when the light comes on.

 

[CJF]

Something's wrong if you can't get the CEL to at least flash steadily when checking for codes.

Curtis

 

[MoJ]

You don't need a code reader for either the 93 or 91 listed in your sig line - a paper clip will work fine. My guess is a code 71 EGR. As far as the CEL not being on anymore, the light will go on and off on it's own. If the requirements for triggering the CEL are no longer present over a few run cycles the CEL will go off on its own. Don't worry it will be back.

I would first reset the ecu by pulling the efi main fuse for 30 seconds. Next time the CEL comes on be sure you're putting the paper clip in the proper terminal holes with the key in the on position. Have someone else sit in the truck and wait to count the flashes. Code 71 will be 7 flashes followed by 1.