8L90 Transmission Temp

[UrbanRage]

Hey everyone, I'm looking for your input. 

2017 GMC, SLT, Z-71, 5.3, 8-speed w/towing package.

While driving to work this morning, I noticed the trans temp was fluctuating between 60-80 degrees and while in traffic it went up to 117-123. I do believe the culprit is the temp sensor. 

I have seen two different temp sensors, one which looks like the usual coolant sensor and the other one was a harness. Has anyone replaced the temp sensor? If so, did it require you to drop the pan? 

 

 

 

 

 

[m3n00b]

The dealer did this under warranty and yes they had to drop the pan and replace the sensor, harness and do a software update.  

[UrbanRage]

The dealership said there wasn't any codes relating the transmission. In their experience when the temp sensor fails it usually throws a code so they are unsure what the problem is. I've been doing to reading and it seems replacing the temp sensor is straight forward, but before I do this can anyone confirm this is the correct one.

 

https://www.gmwholesaledirect.com/oem-parts/gm-f-harness-24298757

 

 

 

[TigerTruck]

On 10/20/2021 at 9:10 AM, UrbanRage said:

The dealership said there wasn't any codes relating the transmission. In their experience when the temp sensor fails it usually throws a code so they are unsure what the problem is. I've been doing to reading and it seems replacing the temp sensor is straight forward, but before I do this can anyone confirm this is the correct one.

 

https://www.gmwholesaledirect.com/oem-parts/gm-f-harness-24298757

 

 

 

Every get an answer on this? Yes, that is the correct part number. I did this repair last week. I got mine on eBay for $66 265245535711 in case they charge too much. The codes came up last winter but not since and dealer wouldn't repair it. It is a straight forward swap and many videos on youtube. Get the correct fluid and filter it helps the shuddering problem.

[UrbanRage]

Yesterday I replaced the temperature sensor harness (24289757), filter, and fluid. As I thought, the temperature sensor was causing the low and erratic values without generating a fault code. I'd also like to add that using a fluid extractor made the process so much easier and a hell of a lot less messy.