: Slowing Down - Downshifting - Braking



LiquidTrader
05-14-12, 10:08 AM
I have noticed that when I'm slowing down to stop or slow down to make a turn - I feel the downshift or something. A "bumpy" feeling and then when turning and then accelerate I feel a jump.

2005 N* V8

What can this be? I'm hoping it's an easy fix.

Thank you!

dkozloski
05-14-12, 10:23 AM
You're problem is called, a transmission shifting gears to match driving conditions. That's what they do.

Ludacrisvp
05-14-12, 11:08 AM
If you are in sport mode the downshift can be felt a bit more as depending on speed you could be doing engine braking during the deceleration.

LiquidTrader
05-14-12, 11:33 AM
I never use the sport mode. Just in D and that's it. I just feel it when I'm breaking as I can feel the downshift

1BadCadSTS
05-14-12, 02:48 PM
Common problem especially on awd. There a tsb that helps with it.

LiquidTrader
05-14-12, 03:04 PM
What TSB? What is it exactly?

Charles Warren
05-14-12, 09:43 PM
Sounds like a worn diff bushing. If your saying you feel a clunk then that's what's wrong.

EChas3
05-14-12, 10:07 PM
The Technical Service Bulletin (TSB) instructs dealer service departments to apply a modification the the Transmission Control Module (TCM) program to alter downsift points and/or clutch engagement parameters. Such changes can have positive and negative effects.

If you find your tranmission's current behavior irritating, see your favorite dealer to see if your car has the latest TCM update. If it doesn't, it's usually not an expensive matter. But an update might not fix your issue and could introduce behavior you don't like. TCM updates cannot be reversed.

"You pays your money, and you takes your chances."

LiquidTrader
05-14-12, 10:17 PM
No. Not a clunk or anything. Just seems its not braking fast enough and the speed is not matching the braking speed

dkozloski
05-14-12, 11:04 PM
The shift points and characteristics of the transmission are learned behavior depending on your driving habits. You might try removing the battery cables and momentarily shorting them together and then replacing them. This will restart the learning process and may change things for you.

EChas3
05-14-12, 11:26 PM
^^^ There's that, too. It does adapt according to the driver's patterns. Some drivers may not prefer the patterns chosen by the designers..

LiquidTrader
05-16-12, 01:31 AM
Where is the battery and how do you short it?

EChas3
05-16-12, 10:18 PM
1. Remove the passenger side engine cover.
2. Remove the negative battery cable.
3. Remove the positive battery cable.
4. Touch the two cables together for a 5 count to discharge any capacitors.
5. Reconnect the positive cable.
6. Reconnect the negative cable,
7. If the alarm sounds (it should) Press the 'lock' button on your fob.

LiquidTrader
05-16-12, 10:50 PM
Thank you!!

Will driving in sport mode mess up the transmission?

dkozloski
05-17-12, 03:55 PM
No, sport mode will damage anything. FWIW; my AWD was shifting a little harshly. I bought and installed a new battery because it seemed to be getting weak. In the process I performed the capacitor discharge routine. Now the car shifts like it did when it was new.

LiquidTrader
05-18-12, 09:58 PM
How do you perform the capacitor discharge ? It just seems to shift hard when slowing down to complete stop. The last 20mph or so and then when I make a turn then hit the accelerator... You can feel the shift.

EChas3
05-19-12, 11:06 AM
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Post 13

LiquidTrader
06-01-12, 06:05 AM
1. Remove the passenger side engine cover.
2. Remove the negative battery cable.
3. Remove the positive battery cable.
4. Touch the two cables together for a 5 count to discharge any capacitors.
5. Reconnect the positive cable.
6. Reconnect the negative cable,
7. If the alarm sounds (it should) Press the 'lock' button on your fob.


I did this the other day. I had a question, none of my settings were deleted or had to be reprogrammed. Is that normal?

EChas3
06-01-12, 07:44 PM
The only preset that might be affected is the express windows. No other driver-set feature should change. It does reset the adaptive transmission programming and I believe it reboots the main computer & network.

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Your experience is normal.

malatu
06-02-12, 10:35 AM
Do all trim models and years have the adaptive transmission?

EChas3
06-03-12, 08:42 PM
I believe so.