P0700 and p0634

[QUATRO_twenty]

Truck is a 12 Tahoe rwd 5.3 flex 160xxx


I have already had my trans replaced a couple years ago and had to take it back to them a second time about a month after replacing because it was slipping I asked if they had serviced the Tcm when replacing he said no failed to tell me that there could have been another issue causing the trans to fail even though it is common sense I did take his word when he said they had fixed the problem now just yesterday on the highway about 75 mph gets stuck in limp mode for about 3 mins then pops check engine and p0700 and p0634. Guess I'm just trying to see if anyone could shed some light and should I be looking at the tcm it self or wiring. Please and thanks for your time

 

[Geotrash]

Truck is a 12 Tahoe rwd 5.3 flex 160xxx


I have already had my trans replaced a couple years ago and had to take it back to them a second time about a month after replacing because it was slipping I asked if they had serviced the Tcm when replacing he said no failed to tell me that there could have been another issue causing the trans to fail even though it is common sense I did take his word when he said they had fixed the problem now just yesterday on the highway about 75 mph gets stuck in limp mode for about 3 mins then pops check engine and p0700 and p0634. Guess I'm just trying to see if anyone could shed some light and should I be looking at the tcm it self or wiring. Please and thanks for your time

In my opinion, that transmission is going to have to come out - this time by a shop that knows what they're doing. Copying @NickTransmissions to weigh in also.

 

[NickTransmissions]

Truck is a 12 Tahoe rwd 5.3 flex 160xxx


I have already had my trans replaced a couple years ago and had to take it back to them a second time about a month after replacing because it was slipping. I asked if they had serviced the Tcm when replacing he said no failed to tell me that there could have been another issue causing the trans to fail. Even though it is common sense I did take his word when he said they had fixed the problem now just yesterday on the highway about 75 mph gets stuck in limp mode for about 3 mins then pops check engine and p0700 and p0634. Guess I'm just trying to see if anyone could shed some light and should I be looking at the tcm it self or wiring. Please and thanks for your time

What transmission do you have?
Need that information plus use periods in your sentences - it's tough to read the OP the way it's written (if using talk-to-text, you need to go back in and add punctuation in most cases).

Those codes are related to general comm breakdowns between TCM and trans (could be any number of things) and temp too hot (p0634). Here's a page that explains that code.
I'd start by confirming/denying there is an overheating condition and if so, what's causing it (applied elements slipping, trans exposed to hot exhaust gases due to missing shields or other reasons).

 

[swathdiver]

P0634 means the TCM is too hot, overtemperature. It got above 286 degrees. Still under warranty?

 

[QUATRO_twenty]

What transmission do you have?
Need that information plus use periods in your sentences - it's tough to read the OP the way it's written (if using talk-to-text, you need to go back in and add punctuation in most cases).

Those codes are related to general comm breakdowns between TCM and trans (could be any number of things) and temp too hot (p0634). Here's a page that explains that code.
I'd start by confirming/denying there is an overheating condition and if so, what's causing it (applied elements slipping, trans exposed to hot exhaust gases due to missing shields or other reasons).

So sorry I am not a mechanic at all just try and diy stuff before getting robbed at shops.

The truck has a 6l80 trans

And while I was on the highway it turned on the stabilitrack and the traction control light for a couple of mins. While this was happening it was showing just dash marks on the trans temp. After the lights turned off and popped the check engine the temp showed about 267 for the trans. At this point I'm already pulled over waiting for the tow. When I got home I plugged in the scanner and got those codes. The trans is still under warranty so I will be taking it back today and will update you with the findings.

 

[QUATRO_twenty]

P0634 means the TCM is too hot, overtemperature. It got above 286 degrees. Still under warranty?

It is in fact still under warranty i replied to nick transmissions with a bit more info.

 

[NickTransmissions]

So sorry I am not a mechanic at all just try and diy stuff before getting robbed at shops.

The truck has a 6l80 trans

And while I was on the highway it turned on the stabilitrack and the traction control light for a couple of mins. While this was happening it was showing just dash marks on the trans temp. After the lights turned off and popped the check engine the temp showed about 267 for the trans. At this point I'm already pulled over waiting for the tow. When I got home I plugged in the scanner and got those codes. The trans is still under warranty so I will be taking it back today and will update you with the findings.

Sounds good, man. Hope you don't have any issues w/the warranty claim. Meanwhile, I'd flush all of your lines and transmission cooler(s) when the trans is out (or have the shop do it if you're taking it somewhere to do the exchange). Main thing is to ensure there's no debris clogging up the lines, etc otherwise the new transmission will have lube issues and possibly get damaged which may not be covered if it was determine to be caused by clogged/restricted lines.

 

[swathdiver]

What Nick said! ^^^^

Major cause of transmission failure after rebuild is clogged transmission oil cooler and lines. The shop manual specifies how to use the TransFlow machine to do the procedure and the numbers for pass and fail.