My check engine light will start to "blink" on and off when I am climbing a prolonged incline (after about 40 seconds at 3000 RPMs). After I return to level driving conditions and the transmission goes into a high gear, the engine light stops blinking. I have 135,000 mile on the truck and I have kept it's maintenance up to date. After I had notice the problem, I had the transmission checked and I had the engine tuned up, yet the Engine Light still blinks.

Any Help??

 

"Blinking SES light=misfire detected" straight from this THREAD. Check that out and we'll go from there.

 

Something is deffinitly creating a misfire in your system. Have your truck running and look at your wires for any blue arching could be a bad wire!!

 

I just had new wires installed last week, along with a complete tune up. I looked under the hood this evening and did not see any "arching."

Could it be the fuel filter located on the frame rail under the driver's seat needs to be changed?

Thanks