My 03 MCS (6-speed) suddenly stalled when pulling toward an underground garage exit, just when I blipped the engine slightly.

I then started it a few times, the engine RPM dropped to the floor very quickly and kept stalling.

I gave a bit of gas as soon as the engine was cranked up, then kept my throttle on to avoid the engine from stalling. I drove at 20km/h with the car weaker than a bicycle, not responding to any bigger throttle input. I was luckily enough to get home that was within 2km.

The engine oil is in the middle of the mark, coolant looks okay, no apparent overheating when the hood was opened. Gas filler cap was a bit loose, it was too easy to be opened after closed with a click.

There are 3 lights went on: DSC, SES, EML.

This is the code read from the OBD port:

01/04: P1125
- FREEZE _frame_ DATA -
Fuel Sys 1 CL
Calc LOAD(%) 24.3
ECT(celsius) 101
STFT B1 (%) -4.6
LIFT B1(%) -5.4
MAP(kPa) 34
Eng RPM 1346
Veh Speed(km/h) 14

02/04: P1229

03/04: P1125

04/04: P1229



Any ideas?

 

It's sounds just like mine and I have no idea what the heck it is... Sorry, I just made a post about this myself...

 

throttle body sounds shot. check the connector but it sounds internal to the electical housing

P1125 Throttle position sensor A and B range performance small error

P1229 Throttle sensor adapation failure



SI M 12 04 02
Engine Electrical

March 2006
Technical Service

This Service Information bulletin supersedes S.I. M12 04 02 dated August 2003.
[NEW] designates changes to this revision
SUBJECT
EDK Throttle Faults on W10/W11 Engines - Diagnostic Procedure

MODEL
Cooper with W10 up to 06/2003
Cooper S with W11 up to 06/2003

SITUATION
The "Check Engine" and EML lights are illuminated; engine may go into fail-safe mode. Some of the following intermittent and "currently not present" EDK (electronic throttle) related fault codes may be stored in EMS2K fault memory:
^P1226 - Throttle malfunction, plausibility
^P1125 - Throttle potentiometers, range plausibility
^P1692 - Electric throttle monitoring, plausibility
^P1693 - Electric throttle monitoring, plausibility

CAUSE
The possible causes may include:
1.Internal failure (defective crimping) of the EDK motor.
2.Resistance fluctuation at X6390 EDK connector due to pin contamination.
3.Signal interruption at X6390 EDK connector due to faulty crimping or defective female pins.

CORRECTION
On a customer complaint basis only, follow the diagnostic and repair procedure described below.
PROCEDURE
1.Connect vehicle to DISplus/GT1 and read the fault memory
2.Remove air filter housing and adjoining rubber boot at EDK throttle. For removal instructions refer to RA 13 71 031 found in TIS. Do not remove throttle.
3.Check the EDK throttle production date printed on the black plastic housing of the throttle. If the manufacturing date is "01-05-02" (1st of May, 2002) or higher, EDK has the latest level of improvements and should not be replaced. If the production date is prior to "01-05-02", the EDK throttle has to be replaced with the improved part.
4.Replace engine electrical harness regardless of EDK production date.

 

Thanks for the info, 1FSTMINI. I took out the intake air duct and all the connectors look solid to me.

EDK throttle says "08-05-03", so the throttle body should not be replaced.

To replace the engine electrical harness, does it mean I have to flatbed it? My car is out of warranty, how much is that electrical harness?

 

12517533103 $303.40

if you dont feel safe driving it id say have it towed. as for how much it would be to install, i couldnt tell you but im sure the dealer is going to charge a lot.

 

I had the same thing last summer. It ended up being the throttle body motor. Replaced the throttle body and all was well.

 

I found that the one of the intercooler boot was worn down on part of the bottom side, so I bought new boots.

I'm going to take the throttle body out and clean it.

The gas filler cap is quite loose, the click is there when closing, but little effort is required when opening it.

I'm going to try all these, clear the code and see if helps.

If it is the throttle body, I think I'll either have it rebuilt, or buy an M7, or buy a new one from dealer.

If it is the engine harness, how hard is it to install it by myself? I've never dropped the engine, transmission, supercharger, radiator before. But I've made it so far to the throttle body and it seems not hard.

Is there any DIY manual on installing the engine electrical harness?

 

Update:

The car is back to normal.

I disassembled the intake path. The CAI intake was very dirty so I cleaned it and re-oiled it. I found that one of the intercooler boot had a torn so I replaced them both with new ones from dealer. The throttle body had a thick layer of grease so I cleaned it as much as I could. I also disconnected and reconnected firmly all electrical harnesses around them. I finally erased the error codes and went to drive a few miles, and everything was fine.

I still don't know where the problem was. It could be the dirty intake, the dirty throttle body, the torn intercooler boot or something else. It could be also because of the recently installed lightened flywheel, Cusco LSD and lightened crank pulley causing more engine movements and loosened wire harnesses over time.

Wish me luck and this issue never come back. =)

 

I can't believe this problem still came back to bite me.

The error codes are: P1125, P1229

It happened a few times last year, it seemed to go away after cleaning the throttle body and making sure all the connectors are firm.

Well, the problem came back again yesterday, and today my battery just died after 8 years of use. I replaced it with a new battery but probably because the battery is not fully-charged yet, the car is still in limp mode.

I'm charging the battery in my garage and see how it goes.

Are these codes really battery related?

Or I need a new throttle body assembly ($$$)?