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Climate Control Unit (CCU) - Fahrenheit to Celsius Conversion

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Introduction

The Climate Control Unit (CCU) consists of two parts: The main PCB and the front unit. The main PCB is identical across all model years and target countries the vehicle was produced for. The front unit is different with regards to the temperature dial and temperature value on the display, though.

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Celsius CCU - 'J' marking
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Fahrenheit CCU - 'A' marking

About half of all NSX produced are equipped with a Fahrenheit front unit, marked with an 'A'. Even though the display and buttons are the same, the Fahrenheit dial has about twice as many stops and a different cabling on the back.

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Celsius Front Unit - Backside
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Fahrenheit Front Unit - Backside


Conversion
By unpinning or disconnecting the wire loop on the second vertical connector (counting from the left) the temperature value shown on the display turns from degrees Fahrenheit to degrees Celsius.

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Wire Loop to disconnect


Drawback
The lowest value (18 C) is unaffected and one stop on the dial still represents one degree. Unfortunately, as the temperature dial of a Fahrenheit CCU has roughly twice as many stops compared to a Celsius CCU, the dial is maxing-out (32 C) after about half of the dial's range.

Notes
Thanks to Drew from NSX Prime on how to perform this conversion as well as help with the images on this page.

Updated 02-01-2021 at 10:04 AM by Heineken

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Comments

  1. goldnsx's Avatar
    I've did this for a German owner, but 10 years ago and didn't recall how I did it. Thanks for the refresh of my memory.
  2. Heineken's Avatar
    Than this would be your message, I suppose: http://www.nsxprime.com/forum/showth...=1#post1146389

    Quote Originally Posted by goldnsx
    I've did this for a German owner, but 10 years ago and didn't recall how I did it. Thanks for the refresh of my memory.
  3. goldnsx's Avatar
    11 years back. Thanks.
  4. Heineken's Avatar
    You're welcome

    Quote Originally Posted by goldnsx
    11 years back. Thanks.