I have an '02 MCS with build date 8/02 w/ 72k miles on it. For the past few months it would randomly go into limp mode while on the freeway or at freeway speeds - typically not under load. SES and EML lights would come on and P1688 code would show.

I finally narrowed it down to the BPV going bad . . . currently in idle it opens/closes (if open means the rod is extended and closed it's depressed).

Now things get worse . . . so when I was finally ready to oder the DT BPV, my wife was driving the car home and it stalled 5 times in a few miles. She got it home and it sat until I could take a look at it.

It's current state is parked in the garage and it has P1125, P1126, and P0638 all showing and will not clear. When I turn it on the car idles wildly between 700 and 1500 RPMs, there is 0 throttle response and the BPV moves in and out like a slide whistle. I have not tried to put it in gear due to no throttle respoonse.

I have read as many threads as possible, but all are 2+ years old, so thought I would start a new one.

Any suggestions?

 

These are from Bentley Manual

Throttle Body Position Sensor issues:
p1125 4389 tps performance small error
p1126 4390 tps performance large error

You might need to replace the sensor.

P0638 Throttle Actuator Control Range/Performance
You might need to replace the throttle body. Again check all the connections on these.

Now for the P1688 code, I would look at your crank pulley and belt and see if there are any issues. Slipping of the belt can cause this So check your belt tensioner as this can be the cause of the slippage. The crank pulley is known to cause this code also because it is rubber on metal and the rubber over time fails.
This is just my opinion on where I would start looking. Good luck.

 

Braminator - thanks for the help.

Is the TB sensor located on the right side of the TB (plugged into the TB)? Would a careful cleaning be a first step? Any suggestions on what to clean with? Same question with the TB?

To replace - are they one part/piece?

Now to the crank pulley - is this the big damper pulley? I know ATI makes one, any suggestions on a replace though?

thanks.

 

So I cleaned the TMAP, MAP, and TB sensors - also cleaned out the TB (dry because the cleaner I got was not for SC use). I fired it up and BINGO! Steady idle, reved perfectly on throttle and then I took it for a quick spin and it's pep is back!

I need to clear the codes and make sure they stay off as well as some preventative maintenance, but there is nothing like the feel of a mini running well!!!

Thanks for all the help with this one!

 

That is great news. You could always disconnect the battery for a few minutes and it will reset itself. Good luck and motor on.

 

I have a 2006 with the same codes. Just had my TB replaced last month and the codes are back. Does anyone have a pic of where these are located so I can clean and check them too?

Greg

 

P1125 & P0638 codes come up when 06 MCS goes into limp mode. TB, TPS and Crank Sensor have (allegedly) been replaced. I would really appreciate it if someone could post pics of where these items are located so that I can check status of the connections.

 

IMG_1462-1.jpg?t=1276968193

 

I have an 02 MCS and have had the same issue a couple of times over the last 4 years. IIRC the issue is the electrical connection and Mini's solution is to replace the wiring harness.

As you found, a cleaning and re-connection can help. I have contemplating looking at replacing just the lengths of wire and connector to the TB to see if that would help rather than replacing the entire harness.

 

If the problem occurred only a couple of times over the last 4 years, I wouldn't be too bothered. My 06 MCS did it 4 times in a 14 miles drive yesterday. Weird thing is that it if I shut down, pull the key out, count to 5, and re-insert the key, it fires up perfectly -apart from the check engine light staying on. Even weirder, the check engine light goes out if the car is parked for a couple of hours.

 

Can anybody help me locate the TMAP, MAP, and TB sensors? I am getting a P1125 & P1126 error codes.
Thanks.

 

I am thinking that some are in the throttle body. Were you by chance working down by the throttle body before the codes showed up? Allot of time the pins in the TB plug get bent over.