6L80E bad 4-5 shift multiple codes

[Jared’s Chevys]

I have a 2008 Yukon XL Denali with the 6l80e and it feels like you got rear ended when it shifts 4-5. I took it to trans shop and had codes read. It is reading

p0989 TFP Switch 5 low voltage

p0842 TFP Switch 1 low voltage 

p0872 TFP Switch 3 low voltage

p0877 TFP Switch 4 low voltage

I have found very little on this but was just wondering if anyone had a common issue or had fixed this before. Also could these codes cause that shift problem?

[silveradosid]

would definately cause shifting problems should check wiring harness going to the tranny

[swathdiver]

You probably need a new TCM.  The shop should be able to perform this test and subsequent testing that they should already know about:

 

CIRCUIT/SYSTEM TESTING
1. Ensure the TFT is near the temperature displayed in the Failure Records.
2. Start the engine and place the transmission range selector in D6.
3. Observe the TFP Switch 5 parameter while commanding 1st gear and then commanding 2nd gear with the
scan tool. The TFP switch 5 should transition from low in 1st gear to high in 2nd gear.
 If the TFP Switch 5 parameter state does not change, perform the Control Solenoid Valve and
Transmission Control Module Assembly Inspection .
 If no concerns are found, replace the control solenoid (w/body and TCM) valve assembly.

[Jared’s Chevys]

Ok, my next question is with 205k do I go ahead and just rebuild it and replace tcm or just drop pan replace it and keep hauling ass?

[swathdiver]

If you have the means and time now, rebuild the whole thing and use upgraded parts.  This way you won't have to go inside again for years to come.

[CheaperToKeepHer]

On 12/14/2017 at 9:02 AM, Jared’s Chevys said:

Ok, my next question is with 205k do I go ahead and just rebuild it and replace tcm or just drop pan replace it and keep hauling ass?

Hi Jared- Just following up on what you did to clear the codes and how much did it set you back? Thanks- Alex

[Hillwood]

Put a new Fluid Pressure Switch in it and see if that fixes it..

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