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Sup guy after my tranny sway auto to built tr3650 I am having an issue with the mph gauge "floating" around it's really bugging me bc that the only thing wrong with the car.. Any input would be great


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Sup guy after my tranny sway auto to built tr3650 I am having an issue with the mph gauge "floating" around it's really bugging me bc that the only thing wrong with the car.. Any input would be great
I assume you meant tranny swap and the auto-correct function mangled it.

Was your tune modified when the swap was done?

I ask because the "mph gauge", more commonly known as the speedometer, is electronically driven by the instrument cluster microcontroller, based on data packets received from the PCM. The PCM creates this data based on the pulse stream received from the transmission output shaft speed (OSS) sensor.

The OSS sensor is an electronic device that produces one pulse for each "hole" in a toothed collar mounted on the transmission output shaft. This collar has 6 teeth on the 4R70W auto and 12 teeth on the 3650 5-speed--I.e. the 3650 output twice as many pulses as would the auto, confusing the PCM.

So, the bottom line is that if the tune was not modified you need to have the scalar value Output Shaft Pulses/Revolution changed from 6 to 12.

There are also three other scalar values in the tune that should be changed:

  • Auto Transmission Switch: set to 0 for manual;
  • Transmission Load Switch: set to 0 for manual;
  • Transmission Type Switch: set to 0 for manual;
 
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So I have to talk to me tuner see if he can change it? I'm running a bama tune haven't swapped it sense I did the swap
"Since" you did the swap, and yes you do need to tell you tuner you changed over to a manual tranny. It may still be that something is not connected properly, however until the tune is fixed it will be very difficult to track down any hardware problems...
 

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You won't be able to change the trans functions via the handheld tuner. You'll need to return the handheld to a human tuner to disable said functions then download the new program via handheld.
 

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Discussion Starter #7
You won't be able to change the trans functions via the handheld tuner. You'll need to return the handheld to a human tuner to disable said functions then download the new program via handheld.
Thanks man, I started the bama tune and left in the comment space below the info I had gotten a call an hr later saying he has to make an appointment with me to understand what's going on bc also the traction control button won't turn off even if I click the button


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Thanks man, I started the bama tune and left in the comment space below the info I had gotten a call an hr later saying he has to make an appointment with me to understand what's going on bc also the traction control button won't turn off even if I click the button
By "won't turn off" do your mean the yellow indicator is always ON or always OFF?
 
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