Where can I locate the transmission control unit for a 2012 Chevrolet Express?

Asked by GuruDDYNT3 Sep 22, 2023 at 01:01 AM about the 2012 Chevrolet Express 3500 2LT Extended RWD

Question type: Maintenance & Repair

Chevrolet Express cargo van intermittently fails to
start. Battery is full power and when you go turn the
key from accessory on to starting all lights go off
on the dash. There is no noises at all. This will
continue to happen for at shortest 10 minutes or
enough to get a tow and then start by the time it
makes it the mechanics. It also intermittently will
just turn off while driving. You can be just driving
and you lose power steering and realize the engine
is just off. doesn't give any signal. Doesn't stutter,
just loses power. When either of these scenarios
happen, it pops codes U0100 & P0700. These
codes usually clear themselves within 50 miles. The
van will also go a couple days without any issues or
have issues multiplied times in one day. It's been to
multiple dealerships and mechanics. We've
checked all the, have changed ECM and BCU. Since
we're getting the P0700, I would like to try a new
TCU. If anyone has an idea where it's located or any
other ideas would be really appreciated.

Thanks

GuruDDYNT3 answered about a year ago

Both have been replaced and tested:-)

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Gene answered about a year ago

P0700 is a very broad code, could be anything from dirty transmission fluid to a complete transmission overhaul. As these transmissions have a lot of shift solenoid failures I recommend you have a transmission shop do some stand alone testing first. Throwing parts at something hoping it will go away is a real budget killer. In my time I think I have only repalced 3 or 4 TCM's that were totally fried. Try an find a shop that's been there for years as they will have the most knowledgeable techs. Stay away from dealerships.

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Gene answered about a year ago

Oh the module is usually located on the firewall right by the brake booster. You will need the numbers off the unit so the parts guy can match calibrations. I don't see it in aftermarket, but I could be missing it.

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James answered about a year ago

This sounds like a good old fashioned battery cable connection problem. Most likely the ground cable where it bolts to the frame, engine, or whatever it bolts to is rusty, dirty, or corroded. Check both battery cables at both ends. Make sure everything is clean and tight. Put some Vaseline on the battery terminals where the cables bolt on to prevent future corrosion. With all the electronics on a modern vehicle a bad ground, especially an intermittent one, can cause all kinds of crazy things to happen! Hope that helps! Jim

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GuruDDYNT3 answered about a year ago

Yah looks like TCU is this one is inside the transmission, so not attempting to replace that. all grounds and battery cables have been cleaned/checked. New battery, Battery Cables, Starter, BCU, ECU, Ignition switch, ignition cylinder. The no start issue is never present after being off over night. Always show's up after its been in use for over 4 hours. The not start usually does not lass longer then 10 minutes so hard to take it to a shop. At such a loss and the problem will not stay an issue and is intermittent. We have 8 of these express vans and this is the first time we have had an issue like this.

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GuruDDYNT3 answered about a year ago

https://youtube.com/shorts/px6aR2QrJJk?feature=shared

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Where can I locate the transmission control unit for a 2012 Chevrolet Express?

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Where can I locate the transmission control unit for a 2012 Chevrolet Express?

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