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Larger Tires & Speedo / Transmission Shift Point question

sh00ter

By sh00ter
in Modifications & Accessories

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TJay74 Senior Enthusiast

TJay74

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Posted

Daniel,

 

Was it one complaint or several that got you the updates? Could you post up the service number for the PI that was used by chance? My HVAC operates funky and the next time I take the truck in for the oil change I was going to have them look into reflashing the HVAC module.

DanielAcosta Enthusiast

DanielAcosta

Posted
Posted

Daniel,

 

Was it one complaint or several that got you the updates? Could you post up the service number for the PI that was used by chance? My HVAC operates funky and the next time I take the truck in for the oil change I was going to have them look into reflashing the HVAC module.

It wasn't the HVAC module, it was the large radio display in the center, but the fix included the HVAC system which apparently runs through that display. When you go in, just ask them to check to see what outstanding updates are available for you, and if you're still less than 36K miles it should be done no questions asked. The particular update I just had done was to the HMI module.

 

You are correct in that sometimes they do ask for a symptom that matches the needed update, so I gave them a couple. Here's what the repair ticket says:

 

Radio favorites will disappear and then come back after key cycle; voice prompt length changes itself to long after being set to short; reference PI 1126D. Performed PI 1126D, reprogrammed HMI module 2881168

 

I think the 2881168 might be an internal code and what you really need is the PI 1126D

 

There is a sequence of buttons they press on the dash that pulls up your software version; if the latest software version is newer, you qualify for the upgrade. I wasn't aware until after the fix it would improve my A/C performance, but it did. Specifically, the fan speed is more gradual in its speed changes, it doesn't use recirculate as much, and when I hit the A/C button to manually turn the A/C off it turns off right away (before it would think about it for awhile).

 

I've had so many software updates in the short 15 months I've owned this truck I have lost count. On the one hand it's frustrating, but on the other it's good that each update has made an improvement. So whenever you're in for service, check to see what's available. Good luck with yours.

  • 5 years later...
bryanhrdz New Member

bryanhrdz

Posted
Posted
On 11/25/2014 at 8:19 AM, DanielAcosta said:

It will correct the shift points and V4 operation, which in turn improves your fuel economy. After 34K miles I'm still averaging 20mpg overall, which seems pretty good to me for a 4wd lifted truck with a stock epa rating of 16/22/18. Take time to calibrate yours with a gps for best results. Even though my tires are 34 inches tall, the Hypertech entry that worked best for me was 33 inches, which is the height of the tires when compressed by the weight of the truck. Good luck.

Which hypertech calibrator did you get?

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