2005 S, seems to run fine as long as I don't turn on the A/C. Friday night though, was a different story. Tooling along fat n' happy, when several dash lights and gauges either lit up or shut off (fuel gauge dropped to the left "E" despite a full tank, etc), and Limp Mode started. I pulled over, shut down and waited maybe 10 minutes, opened the bonnet for a peek, to appear as though i knew what I was doing. Then, the engine started and ran fine (CEL was on, but the fuel gauge was awake again and the other lamps were out). I thought maybe I had accomplished some kind of a re-set, and drove the short distance back to work.

At the time I didn't realize the correlation, but when I operated the A/C, it was only a matter of a few minutes/miles before Limp Mode came back. To get home that night I think I had to stop and restart 2 more times, getting normal engine response each time. The CEL even went out.

Auto mechanic next door loaned me his expensive reader on Saturday morning, and I saw p1688 but he (and me too) couldn't relate that code to a specific cause for Limp Mode. I have the text from the reader here someplace but it mentioned the computer output circuit - pretty useful huh? I don't know which is worse a computer problem or an A/C repair (read on...)

So I ran a few local errands without a problem, until i turn on the A/C then bingo, Limp Mode. Same solution, I shut down and re-started and got going again. Today I just didn't use A/C (which is a PITA! to do without!) and had an uneventful trip of about 100 miles...

Is my A/C compressor seized or the A/C "clutch" likely busted? Could it be a belt issue?

At one point on Friday night's ups and downs, i noticed a "hot engine" smell, and checking the coolant reservoir I could see the ends of the pipes in the base of the container, so I added about 8oz of bottled water but at NO time did the temp gauge in the dash ever exceed normal (middle) range, not even by a smidgen. The smell must have come from some other cause, maybe it's the root problem. There were never any puddles or drips under the car.

So, thank you for coming this far reading my romance novel of a car story... What could be the matter?

Thanks,
Tatt

 

Take a look at https://www.northamericanmotoring.com/forums/drivetrain-cooper-s/155159-p1688-limp-mode-smoke-burning-smell.html

 

Related TSB info
"MINI COOPER S TSB M12 200 04

Engine lack of power and/or SES Lamp on DTC 1688"
http://www.coremini.org/forums/showthread.php?t=57

Good luck.

 

Tks papa for the posts. The TSB is interesting but probably not applicable to my issue (plus I already saw Richard's thread too, earlier tonight).

Am I wrong or wouldn't I have driveability issues under all circumstances (if bp valve was flaky)?. I only get stuck in failsafe/limp when I operate the A/C compressor.

Speculating here: P1688 is a weird code. It might be just telling that the car spent time in Limp Mode, rather than providing information specific to the root cause. I don't know, but he CEL always goes out (well so far) after a couple starts.

Thanks again. I'm still searching for the answers,
Tatt

 

WOW! All this crank pulley talk going on. Weird.

Anyway, tattman23- at first the husband was convinced that our problem was only because of the A/C compressor. He was doing all kinds of testing and thinking it was just that. So he DROVE it (because he was SO convinced that he would make it to the shop as long as he didn't run the A/C). I drove behind him... finally smelled burning rubber smoke... made him pull over... and that's where the belt snapped and we had to be towed two blocks to the shop. BTW- it was intermittent at first. Near the end, it couldn't go far at all without limping... regardless of A/C. Fortunately we had no overheating or additional damage.

 

I had the same issue this morning. I seem to get limp mode when it rains. The engine bogs a little depending on the rains intensity. This morning we had a monsoon and I hit a puddle/pond. The belt slipped, full limp mode. I had to shut it off and sit for a few minutes. Fire back up and everything seems fine. I think I'll give the belt a really good look though.

So I think code p1688 is related to the Super charger or A/C (I had the AC on) not spinning at the proper speed.

 

i wish someone knew the answer to this, i'm getting the EXACT same issue. I'm not going to drive it until i know what it is. But that makes us a 1 car family again.

 

My thoughts are slipping belt/bad battery syndrome. These new cars really don't like the voltage to go below a certain point. You can test the alternator with everything running and see if it is working well enough, if not, check the belt. They stretch and start to slip.

 

I am having the same problem and code. Did anyone ever determine the solution? Was it just the old belt needing to be replaced?

 

Gosh that was some time ago... The fix was replacing the allegedly seized up A/C compressor.

That was a long, expensive day @ the dealership, in part b/c they mis-diagnosed and replaced the supercharger bypass valve and buttoned everything back up, BEFORE they figured out the actual problem . Brilliant.

They also installed a new belt, but just because it was due, not because it was busted. I kind of think the original belt must have got somewhat baked, trying to turn the compressor anyhow.

Plus i got to keep the SC bypass - guess they didn't want to pull it back out.