My MINI's had an interesting change in behavior the past two days. Yesterday morning I chalked it up to the torrential rain, but after last evening's commute home and another morning commute in better conditions, the symptoms still persist.

The scenario:
I have a stock '05 MCSa -- that is the 6-speed Aisin torque-converter automatic transmission.

My total drive each way is about 3.5 miles over 12-15 minutes. This is urban driving -- about 30mph on average -- with about a mile stretch where I'm in the 40-45mph range. Traffic generally flows pretty freely except for the last mile or so where there's a succession of traffic lights, and it becomes more stop-and-go.

I generally keep the transmission in automatic -- rather than "manual" -- for city driving.

The intriguing developments:
Yesterday morning -- in the midst of the torrential rain -- I noticed that the transmission seems to be delaying the upshift from 2nd to 3rd, until the rpm gets above 3k (which seems considerably higher than normal in city driving). There's no problem using the paddles to upshift manually.

Then, in the last 1/4-mile of my commute there's an underpass. There was no noticable change in traction or road conditions, but yesterday morning my DSC suddenly kicked in on the upgrade, and the car refused to go above 20-25mph (I normally do 30-35 in that area). The rpm were pegged at about 2k. Yesterday the DSC stayed active as I limped the final 100 yards to the parking garage; this morning I turned off the DSC and proceeded to the garage without further incident.

Coming home yesterday, I didn't have any issues with the DSC, and wasn't able to tell about the upshift issues as evening traffic was more stop-and-go. Obviously I'll pay close attention again this evening.

Yesterday I chalked the odd behavior up to the torrential rain -- DSC possibly activating due to slick road conditions -- but the symptoms returned this morning under more favorable weather (dry, 40-44F).

Aside from the DSC light blinking when active, I'm not getting any other service/warning lights.

In terms of what changes have been made recently to the car:

- Tuesday, 12/1 -- topped off the gas w. ~10 gallons of Gulf 93 (from my usual gas station)
- Thursday, 11/26 -- installed rear fog lamp module
- Monday, 11/23 -- replaced control and trailining arm bushings and flushed brake and power steering fluid
- Saturday, 11/21 -- replaced original toggle bank with full toggle bank

I can't imagine any of these changes would necessarily effect the transmission or DSC....

Anywho, I have an appointment at the dealer tomorrow AM to have my rear foglights activated. I presume it's safe to make the hour-and-a-half trek down there -- and then back again. Any thoughts as to what's going on or suggestions for what they might look for while I'm there?

Perplexed,
T.

 

Sounds like it may be a bad ABS sensor.

 

You bring up several interesting points.

First after work take a much longer way home and do more evaluation, fast, slow, all sorts of conditions and see what happens. This extra drive will also do your oil and exhaust good to drive out the moisture... you should do this regularly anyway. And it will just be fun to drive more in more pleasurable conditions.

You did replace your toggle bank and your DSC switch is one of those switches. If this problem persists, I would check that switch, possibly put the original back in for diagnostic purposes.

When your DSC kicked on, were you front tires spinning?

Last item, you say you flushed the power steering? Just for my info, please tell me your flush method, what fluid you used and how much of that fluid was necessary?

YD

 

I thinh a few potential issues

you said>>
- Monday, 11/23 -- replaced control and trailining arm bushings and flushed brake and power steering fluid
- Saturday, 11/21 -- replaced original toggle bank with full toggle bank

The brake fluid flush may be suspect ... did you have your keys ON and also STOMP on the pedal while flushing ... or "open the circut on the system" ?
If not A you may not really have done a full flush (but that wouldnt make a big diff to the issue you are having) or B you may have air in the system or even the ABS system.

the toggle bank change may have caused an issue with the circut somehow ...


... "yo's dad" .... for the PS ... 1 liter of CHF 11S fluid will be what you need.

 

Thanks for all of the feedback, folks.

Re: the PS and brake flushes -- My wife brought the car in to this our trusted Local MINI Guru (non-dealer) to have this done; I'll have to check w. him on that.

Re: the toggle bank -- original had DSC and front fogs; "new" has DSC and both front and rear fogs. I do have the original toggle bank, so I can swap it back in for diagnostic purposes, if needed.

Wheels were not spinning when DSC activated.

 

The MINI gets a longer workout -- besides the short daily commute -- at least once a week, but I'll look forward to the drive home tonight!

 

I'm seconding the possibility of a failing or grungy wheel speed sensor. My car had all kinds of oddities before I diagnosed it, cleaned it, and now they're all OK.

Someone with a scanner that can see stored BMW-specific system codes can see if there's any history of weirdness with the wheel speed sensors. This won't necessarily light any warning lights (though it usually results in some).

 

Paul: Would this account for both DSC and transmission issues?

I was planning on going to a dealer tomorrow for something else anyway, but is it an easy DIY to diagnose/clean the wheel speed sensor(s)? (I'm not exactly a "greasemonkey" )

 

Possible that the transmission adapted shift points based on perceived traction issues...

 

Ah-ha.... Interesting....

 

I had this also with a bad sensor and it happened after a bad drive in the rain also, once it was replaced all was well

 

+1 on that blimey-man. 'zactly what I was thinking.

 

I really don't think many of these sensors actually "fail" - but that some combination of crud on the sensor itself, and moisture in the connector just causes them to read unreliably. I pulled mine out (easy), unplugged it, cleaned it, reinstalled, and used dielectric grease on the connector. No more problems.

 

Wow; thanks again folks!

This just reinforces what a great repository of MINI knowledge NAM is.

I'll get in touch with the MINI SA I'm seeing tomorrow AM and get them to look at/clean the wheel speed sensors. (Probably good to read any codes, first, of course!)

Of course, if anyone has additional thoughts in the meantime, I'm all ears....

 

+1
But I think that dealers will just replace the cruddy sensor, well from what I've seen on other similar threads.

 

I think you are right, all the reading I have done on these is exactly what you guys have said, take it apart clean it and you are good to go and can save some coin, the dealer just replaces, or at least you hope they replace it as i am becoming very leary of them working on the car. They told me I needed a window regulator, cost was over 600.00. I took the door panel off when I did some sound proofing, and the problem with the window was one of the speaker crossovers in the door came loose, fixed in 5 minutes and saved 600.00, I know a bit off topic but it shows what you learn here can save you plenty

 

So I took a slightly circuitous route home tonight, as suggested upthread by Yo'sDad, taking 20 minutes to cover nearly double the distance (6.5 miles) of my morning commute.

Traffic was mostly free-flowing, average speed probably around 30-35 -- topping out around 40mph for one 2-mile stretch.

The transmission issues persist with some regularity. Upshifts from 2nd to 3rd generally occurring around 3000rpm. There was one prolonged stretch where I the revs were up around 4000rpm (35-40mph) before I used the paddles to upshift. (Revving that high while moving that slowly didn't seem healthy.)

The DSC seems to be kicking in more regularly, particularly while accelerating, turning, climbing, or any combination of the above. I'm not noticing any wheelspin. That said, the DSC also seemed to be active for stretches on flat, straight road at fairly steady speed (25-30mph).

I purposefully took a route that included a couple of inclines -- a couple of bridges and short hills. While the DSC didn't seem to interfere with acceleration on flat ground, revs again seemed to be limited to around 2k when doing any sort of climbing, and speed was limited to the 20-25mph range.

There was one point where I made a right-hand turn from a stop sign at the top of an incline, and the DSC did not activate.

My gut sense is that this evidence further implicates the wheel speed sensors, but will hopefully find out for sure tomorrow after I make my 90-mile trek (mostly highway) down to the dealer.

 

Good luck!

 

That does not sound like a lot of fun. Hope you can isolate the cause and find a fix.

 

Well, the good news is that I got my rear fog light activated.

Unfortunately the dealer was unable to diagnose the DSC issue. Their diagnostics indicated it might have been a bad steering angle sensor, but that didn't do the trick. They want me to come back next Saturday so they can keep at it....

The drive down to RI and back did yield some additional data, however:

DSC kicks on/shifting issues persist w. some regularity in in-town driving (20-40mph).

On the highway, it seems that the DSC would kick on between 50-60mph, even in dry conditions. There seemed to be some correlation with climbing, but not 100% consistent. Only at the lower end of the speed range did it seem to interfere with throttle response.

After about 20 miles on the highway (I-495), traffic opened up to flow between 65-75mph with some regularity. At those speeds, DSC did not activate, even on inclines, or when it started to rain.

Transitioning from I-495 to I-95, highway traffic slowed again -- there's a stretch between Pawtucket and Providence where speeds are 50-55mph -- and the DSC issues re-emerged with some persistence. Off the highway, with city traffic doing 20-35mph, the DSC was active pretty much constantly and the shifting/acceleration issues reemerged. Switching off the DSC seemed to rectify both.

On the return trip, DSC was active pretty much constantly for the first half of the stretch of I-95 between Warwick and Pawtucket. (Speeds around 50-55mph.) Because speed/acceleration was limited by the DSC, I decided it would be safer to switch it off, even in the steady rain.

Back on I-495, I turned the DSC back on, with speeds now between 60-70 mph. DSC seemed to go active pretty regularly between 50 and 65 mph. From 65-70 DSC activation is about 50/50. At 70mph and above (tho not too far above), DSC remained quiet, regardless of road/weather conditions.

At one particularly quiet stretch, I was able to move to right lane and slow from 70ish down to about 50-55 to see if the DSC would come on. It did not. I'm not sure what that tells us.

Off the highway and back on local roads, I kept the DSC on to see what would happen. The car actually behaved normally for a short while, before the DSC started acting up again.

I took some of the same roads as I did in my evening commute yesterday, and this time switched off the DSC to accelerate onto the bridge. Not surprisingly, throttle response was much better this time!

I'm hoping I can get my Local MINI Guru to take a look early next week, hoping he can work his MINI magic before I head back to the dealer on Saturday.

If nothing else, I can now find the DSC toggle in my sleep!

 

Paul: Is this easy for someone with little to no DIY experience? If so, would you be able to provide some instructions?

Thanks!!

 

A couple of weeks ago I started getting the following additional symptoms:

SES/ABS/DSC/TMPS light trifecta -- regardless of whether the DSC is switched on or off, usually after having been on the road for at least 15 minutes.

Switching to Steptronic mode and the ABS, TPMS, and DSC lights turn off, tho SES remains lit. (DSC still kicks in intermittently.)

Eventually all the lights will go off.... (Although my wife -- who has the car today -- reports that all the lights came on again while she was just sitting at idle for about 20 minutes.)

Had a go with a Solus Pro scanner earlier today and came up with the following:

So, back to the dealer tomorrow to have them sort it all out (hopefully).

 

The MINI is finally feeling much, much better.

I brought it I back down to the dealer this morning with all of the accumulated data from the past month.

Lo and behold, the the wiring from the right front speed sensor had been rubbing against the pulley, which wore right through the sheathing, down to the wire itself. (This might explain the progressive nature of the symptoms.)

In less than an hour, I had a brand new sensor and was on my way home -- a blessedly uneventful return trip.

Better yet, my Very Generous Previous Owner had shelled out the bucks for the extended 6-year/100k mile warranty, so I was only out the $50 deductible.

Props to Jaymes and the gang @ Inskip MINI in Warwick, RI, for the good work!

 

Good to hear it was a simple fix Tim!!