chk eng light after long hill pull no code?

[jbcarver]

2002 f-350drw crewcab stock 7.3 manual trans
runs fine but when i pull a long hill the check eng light comes on? it will never do it without towing a trailer but when i tow my camper flat land it never comes on but when i start up a long hill with a load (camper)by the time i get over it the light comes on if i ease over the hills it wont come on and it gos out in a little bit if i dont pull ahilll very soon after it comes on.i have been to autozone and it never show a code!!
can someone tell me what might be wrong????????????

[c_pilling89]

I have a 99 f250 7.3 manual trans. I noticed the same thing on mine. After a long pull up hill towing a camper the SEL came on and would go out if I'd let off the throttle. My guess was EGT's running high, but that was only a guess. the code never came up.

[hollister25073]

May be an over boost code my comes on at 27psi I think

[jordanmills]

There's a code. The cheap scanner they have at autozone won't pull it. You need one that speaks proprietary ford diesel talk. Take it to a shop, or find someone in your area with autoenginuity.