engine rev's by it self
 

Hello and PLEASE help.

This has happened 5 times now. My engine will start to rev weather the truck is in gear or not and almost caused me to rearend the car in front of me in the drive thru. When this happens it will stop if I touch the throttle. The check engine light will come on and the codes are P1694 P1693 P1687. When the engine light comes on I will usually lose the tach for a moment. I don't need an accident so PLEASE tell me why it revs on its own.

Thanks Corey

sounds like your Throttle Position Sensonr to me i just had mine replaced
not really cheap was like 400 bucks or it could be your fuel injection pump had cooked the electronics. if you start getting a dead pedal i would say the sensor if you dont i would say fuel injection pump.

Those codes are pointing to a ECM problem, or wiring to/from the ECM.

Loss of tach could be the cam/crank position sensor.

I'd start by checking the connections on the ECM, PCM, and related sensors on the engine.


phox

Unplug your Edge and clean the terminals. Also, check the connections on the ECM at the firewall. Usually this problem occurs when the terminals at one end or another are corroded or bent.

ECM is on the side of the engine.
PCM is on the firewall.

:D

phox

Corey, I had a car do the same thing to me and it turned out to be the TPS. It was sticking and and the computer was thinking the throttle was depressed when it wasn't. Try pulling yours and see if it operates smooth. If not, you MIGHT get by for a while getting some lube into it. If not, well, you know the drill.
BTW, You see the post about the MEET and GREET in Duluth?
Tom

Thanks for the reply's, I'll try the connections on the box, ecm, pcm and apps 1st. This sounds like it could either turn into a PITA or an expensive PITA.

Minnesota-Corey, Did you find your problem?
I had the same thing happen to me yesterday. The CE light came on and the truck reved by itself and puffed black smoke.
I unplugged my edge and it idled fine, after about ahalf dozen starts the CEL went out all seems fine now. I still have a code in there ihave to get scanned to find it.
I'm going to plug the edge back in today and see if the problem comes back.
I believe my edge may be causing my problem.

Turbo51015 I haven't had a chance to look at it yet as another problem arrised yesterday. One of my rims has cracked, not a good week by any means. Let us know what happens after you plug back in.

APPS has two idle validation signals. Highly doubt if they both failed causing the ecm to "think" the pedal was depressed.