C4500 loss of power after a very rough road...

[In2toys]

Hey Guys, 2005 C4500 dump truck. 6600 Duramax I hit a pot hole this am on the way home, & after everything stopped flying around the cab The truck went into limp mode, NO codes / ses light on display. The last time the ses light came on it was a fuel filter, this time no light. I'm ASSSSSUMING if it was an injector or something like thast it would throw a code, Correct? Any help would be greatly appreciated.

Some info I forgot. In park it idles just a scoche higher than normal. If I tap the brake it idles down till the brake is released. This is not the same high idle when it's cold out.

[Mark Rinker]

Maybe the rebound from the pot hole incident allowed for a high speed wheel slip (airborne momentarily) that the transmission didn't like?

My C4500 had a dash indicator on the center console that illuminated when the transmission wasn't happy. A yellow 'gear' looking thing IIRC. Only saw it once when testing an 80hp tune with gooseneck on. Backed it off to 40hp and it never came back.

Not sure about the high idle. Did it just start after the pothole incident?

You can reset the limp with most code readers, go to a dealership, or unhook your batteries for a few minutes...

[In2toys]

After much sweating & worrying about broke injectors & such... I finally made it to the dealer to have the service rider get this look on his face I used to give customers when they did something stupid after I told him about the high idle. Evidently a calculator I have in the upper cubby hole bounced out & tripped the pto switch. The truck is wired for one, but it doesn't have one installed. He flipped the switch & problem solved. I didn't even see the light on... Of course all this was after replacing a $45 fuel filter in the Lowes parking lot. It acted just like it did the last time one that went out. Anywho, thanks for the reply.

[Mark Rinker]

Did exactly the same thing with my C4500...and replaced the filter, too. If you don't have a PTO, they should de-activate that button.

Maybe consider unhooking it from behind?

[trbankii]

Don't feel bad. This past weekend none of my dash lights were working - just suddenly. Checked all the fuses. Searched TDP and found some mention of ignition switch problems. Went back out and jiggled the key around. Nothing. Probably spent twenty minutes messing around with stuff. Later, went back out for something and rotated the dial to get the interior lights on to look for what I needed. It didn't even register how far I had to spin the dial... But then when I started the truck, the dash lights were back on. Took me several moments to realize that the dial had them dimmed completely. No idea how that happened...