4l80e no lock up after overdrive?
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Joined: May 2015
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4l80e no lock up after overdrive? Hey guys, just joined the site and I've been browsing and can't seem to find an answer to my problem. So I just picked up a really clean 02 2500hd ccsb 6.0 and I'm having an issue with the tow haul. I haven't dug into the column yet, but the button doesn't work. Light goes on and off like it should, but doesn't engage or disengage the mode. Here's where my issue differs from the rest, it seems to be stuck in tow haul. Later shifts under light acceleration and no lock up after overdrive. Now I've checked to see if overdrive is working correctly, and Rpms jump when put down into 3rd. So my question is, if the truck was in tow haul mode and the wires broke going to the button, would it stay in tow haul. Transmission has a fresh rebuild, 1434 miles, and all the gears work as they should except there's no lock up after overdrive, just 2100 Rpms at 60 with 4.10 rTio. Any help is appreciated. Thanks!
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Joined: May 2015
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Ok here's an update. Woke up since I work nights and pulled my steering column apart, took off the bottom dash bezel as well to check for breaks down the harness. Took apart the tow haul wires cut and repaired, now I have tow haul, however I still have no lock up after overdrive. I've heard mixed answers on whether the brake light switch can lead to the problem, but also read that it doesn't connect to the tow haul circuit, but being that the tow haul is now fixed, could it be possible that that is my issue? I have no dtc or ses lights, and she shifts super smooth. So I seriously doubt it's an internal problem, so I'm kind of stumped. Help me out! Thanks in advance, zack
