2008 Yukon xl Denali p0843

[Mpollard]

i recently purchased a 08 Yukon Denali xl with the 6.2 awd. It has a bad vibration like a cylinder is misfiring but after getting a new fuel pump plugs and wires and still no change. I finally got a code that I can’t clear. It’s a P0843. Any help would be appreciated thanks

 

[wjburken]

After doing a quick search, that is a transmission fluid pressure sensor error code. Might have a bad sensor. Not sure if that would cause the rough running you are experiencing

What other codes did you have that you could clear?

 

[Mpollard]

That is the only code. It shifts and it starts running bad. I can see the rpm go up and down when it does it and u can feel the car vibrating

 

[wjburken]

How many miles on the vehicle?

 

[Mpollard]

189k

 

[swathdiver]

i recently purchased a 08 Yukon Denali xl with the 6.2 awd. It has a bad vibration like a cylinder is misfiring but after getting a new fuel pump plugs and wires and still no change. I finally got a code that I can’t clear. It’s a P0843. Any help would be appreciated thanks

Switch 1 is stuck or has gone bad. A Tech-2 or other bi-directional scan tool can run some tests but you probably need a new Transmission Control Module (TECM/TECHM/TCM/etc.) Transmission shops are going to suggest a complete replacement or overhaul at that mileage.

If you're handy with a wrench, you can rebuild the TCM switches yourself but would need the Tech-2 still to perform a relearn after fixing it.

https://www.amazon.com/dp/B072C63HM...colid=5Z8RL5YK3XLO&psc=1&ref_=lv_vv_lig_dp_it

If you decide to replace the entire TECHM with a new one, stick with ACDelco and not Dorman.

 

[Geotrash]

i recently purchased a 08 Yukon Denali xl with the 6.2 awd. It has a bad vibration like a cylinder is misfiring but after getting a new fuel pump plugs and wires and still no change. I finally got a code that I can’t clear. It’s a P0843. Any help would be appreciated thanks

Did you check the ignition coils and replace any? Two things you can do to check: 1/ Listen to the exhaust to see if you have a miss. 2/ Using a cheap digital infrared thermometer, check the temperature of each exhaust header outlet to find the cool one. 3/ Replace the ignition coil for that cylinder.

Cheers,
Dave

 

[Mpollard]

Took Yukon to local dealer today they seen the code and said it has a internal failure on clutches 4-5-6 and said needs replacing but it shifts too good for all that not to mention they want $5500