Hi guys,
I have an '06 MINI with CVT transmission. In the last couple of days the car has started responding erratically when accelerating - lurching suddenly and jerkily with the rev meter jumping up to 4000rpm suddenly and then back down. Is my transmission failing me or is there a simpler explanation?

 

Sounds like the transmission.
Check the codes just to make sure. If you don't have a code reader go to an AutoZone (or similar parts store) and ask them to check for codes. If there are no codes that will likely point more to transmission failure.
Good luck.

 

[FONT=Arial]SUBJECT
[/FONT]R50/R52 CVT; Engine Speed Flaring on Deceleration


[FONT=arial, helvetica, geneva][SIZE=2]MODEL[/SIZE][/FONT]
R50, R52 Cooper with CVT transmission and W10


[FONT=arial, helvetica, geneva][SIZE=2]SITUATION[/SIZE][/FONT]
The customer may complain of engine speed flaring ("engine revs up") during a closed-throttle deceleration from highway speeds. No faults are stored in the EMS2K/MS5150 (DME) control module.

[FONT=arial, helvetica, geneva][SIZE=2]CAUSE[/SIZE][/FONT]
Unfavorable CVT (Continuously Variable Transmission) gear ratio adaptation

[FONT=arial, helvetica, geneva][SIZE=2]CORRECTION[/SIZE][/FONT]
Clear the CVT long-term gear adaptation values, and perform the complete transmission "adaptation teach-in" procedure, according to the instructions below.

Important Note:

The unfavorable gear adaptation values may be erased, and the correct values can be relearned, by occasionally driving the vehicle in "Sport" or in "Manual" (Steptronic) mode.

Please advise the customer that occasional changes in driving mode (Sport or Manual modes, from time to time) would prevent the engine speed flaring condition from occurring.

[FONT=arial, helvetica, geneva][SIZE=2]PROCEDURE[/SIZE][/FONT]
To clear the CVT long-term gear ratio adaptation:

1. Connect the vehicle to the ISID/GT1, loaded with the latest diagnostic software.
2. Select "Service Functions"; then "Drive" and "CVT gear".
3. From the second column, select "Replacement/adaptation, CVT transmission" and then "Test Plan".
4. Scroll through the next screens and answer "Yes" to the question "Is it necessary to delete adaptation values?"

After the CVT gear ratio adaptations are deleted, perform a complete transmission "teach-in" procedure, as follows:

Clutch adaptation:

1. Press and hold the brake pedal. Start the cold engine.
2. During a cold start warm-up phase (idle speed is slightly increased), shift from P to N for 10 seconds, and then shift to D for 10 seconds. XP will be displayed in the instrument cluster.
3. Repeat the following sequence 10 times: shift from P to N for 3 seconds, and then shift to D for 3 seconds. XP will be displayed in the instrument cluster.
4. Repeat the following sequence 10 times: shift from P to N for 3 seconds, and then shift to R for 3 seconds. XP will be displayed in the instrument cluster.

Gear ratio adaptation:

1. Accelerate the vehicle to a speed of 50 mph. Release the accelerator pedal and allow the vehicle to coast down to a stop. The transmission adapts itself when going through 4,500 rpm, 4,000 rpm...and 1,400 rpm engine speeds. P will be displayed now in the instrument cluster.
2. With the engine at the operating temperature (idle speed stabilized at 800 rpm), repeat Clutch Adaptation steps 3 and 4.
3. Turn the ignition off.

 

Also, *might* just need a re-flash...

 

The same thing is happening to my mini...pulling and jerking..accelerating...Didn't want to go to the dealership cause they charge an arm and a leg to do it. I had someone change my fluid and my filter after I started getting the issue a 1st measure using ZF bmw lifeguard 5 fluid. Is that ok for my mini cooper? I am now going to go the dealership and try the steps you mentioned. They recommend replacing it with the right fluid first which is ATF type jws 3309 and charge me another $300. Should I just get it flashed and have the values relearned? Or do I try one first. Thanks

 

You cant have a CVT with Steptronic interface. that's only used on the Aisin 6-speed conventional slushbox auto that started being offered in the 05 MY. IOW, if U have paddles on the wheel, you do NOT have a CVT, you have the Aisin.

 

MINIFixer,
Your information definitely helps.
Mine has exactly same symptom that is described in your symptom and resolved by lost battery accidentally.