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Old 05-11-2018, 07:00 PM
Willcoc Willcoc is offline
Join Date: Mar 2004
Location: New Paris, OH
Posts: 62
Default TCM module failure?

Pulled out of the garage, went to put it in reverse, then doc shows, service Stabilitrack & service traction control.. limp mode, only Idle in forward or reverse, if reverse works. Disconnected batteries, no change. Friend stopped by with code reader, UO101 lost comm with TCM. Based on some search’s, took of frame ground near fuse block, shined up but no change. Pulled connected and reconnected, no change. Anything else before trying to find a replacement?

We think it is the box with spike things on the radiator is module that is the issue.

Not having much luck finding any Internet source for a replacement, so any suggestions short of the dealer?
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Old 05-11-2018, 07:42 PM
rapidoxidationman rapidoxidationman is offline
Join Date: Dec 2002
Location: Teton Valley, Idaho
Posts: 1,636

check the wiring harness with your nose as well as your eyes. It took me some time to find where mice had nested and eaten some wires under the fuse box, disabling my A/C and glow plugs.
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There's no point being a pessimist - it wouldn't work anyway.
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Old 05-15-2018, 09:19 AM
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More Power More Power is offline
Join Date: Feb 2000
Location: Big Sky Country
Posts: 10,336

I can't remember the last time someone identified a bad TCM - while possible, they just don't place high on the list of possibilities. I agree with rapidoxidationman that it's more likely due to a wiring issue.

Reseat related connectors, check vehicle grounds, check battery terminals and look for rodents...

I keep Decon rodent bait in my garage.
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Old 05-16-2018, 08:30 AM
Kennedy Kennedy is offline
Long Distance Crew Chief for BMDMAX
Join Date: Mar 2000
Location: Loyal WI US
Posts: 10,614

We keep these in stock and program to go for drop in installation. It is primarily a LML thing and seems to be primarily 2011 model year, but there are other years that have issues.

Yes it is on the fan shroud.
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Old 05-16-2018, 12:04 PM
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DmaxMaverick DmaxMaverick is offline
Join Date: Apr 2001
Location: CA
Posts: 12,005

I've heard of, but never seen an actual TCM hardware failure (absent known physical damage). It wouldn't surprise me to find that those I've heard of weren't actual failures, at least a vast majority of them. Some firmware versions are more vulnerable to corruption, which is very commonly misdiagnosed as a module failure. In every incident I've seen, a simple calibration update (rewrite/refresh) resolved the issue(s).
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Old 05-19-2018, 09:29 AM
Willcoc Willcoc is offline
Join Date: Mar 2004
Location: New Paris, OH
Posts: 62
Default Problem resolved

Was out of town so slow response. Found an online source in Cincinnati for a new TCM with programming. Plugged it in, problem resoLved. Sorry, John, already had it on order before you responded. Have the bad one if somebody wants it.

Good to know it is not a common problem.
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tcm module

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