Throttle Actuation Potentiometer Range/Performance

Something to do with the drive by wire system? Had any work done recently?

 

Im pretty sure mine is a cable system. I noticed a cable there before when cleaning my ICV. It seems to always fail when sitting in traffic, which is the worst place for `limp mode`to occur!

 

Even though you have a throttle cable, the ECM still controls the actual throttle opening

Take a look at this document, pages 51-54 -
http://www.beisansystems.com/misc/SEIMENS_MS_420_ENGINE_CONTROL_SYSTEM.pdf

The new engine throttle valve (MDK) differs from the familiar EML in the following points:
***8226; The accelerator pedal potentiometer (PWG) is now integrated in the MDK housing.
***8226; A throttle cable is used to actuate the throttle potentiometers and also serves as a backup
to open the throttle plate (full control) if the MDK system is in fail-safe.

 

Yes you are right I called BMW and the service guy explained how the system works and that even tho there is a cable it is still a wire signal that operates it.
So my next question is, what can I do in the mean time to trouble shoot this problem. I would rather not spend all kinds of money at the dealer ship when I could simply buy the need part and install it myself. I understand that BMW`s reader system could pin point the problem, however it seems to me the main problem is the throttle body its self.

 

You might check is the connection to the throttle body, make sure the wiring and contacts are good and the connection is twisted on completely.
You could check the throttle body and make sure there isn't any build up on the body or butterfly that might cause it to stick.

http://tis.spaghetticoder.org/s/view.pl?1/04/35/75

You might also check the throttle pedal clearance - make sure the cable moves freely.
http://tis.spaghetticoder.org/s/view.pl?1/04/43/52

 

Its so strange how it will run fine for like an hour and then suddenly just quit. And then other times it will consistently turn on and off. There is no pattern, just random malfunction. And almost always as soon as i hit a stop light or slow moving traffic.

 

Did you find a fix... same problem here

 

I put another throttle body in, second hand from ebay. Hasnt come back since.

 

Did you have to program to your bmw

 

My car already has a new throttle body installed. I'm manged to temporarily fix it by cleaning the ICV. I drove it to work and it didnt make it back home. I'm ordering a new ICV to fix the problem.

Info on my car:
I have a 1999 323i (155k Miles) and my car has a Mechincal Style Pedal with no sensor.
Replacing the the thorttle body alone did not clear the issue for my vehicle.

For anyone else that runs into this problem.

 

Idle Air Control Valve did clear my P1542(Throttle Position Sensor Electrical.) but I bought the car with a new throttle body.

I am now running into a P1580(Throttle Mechanically Stuck) sometimes. I took a look at my throttle cable and has a lot of slack, looks like they didnt replace the cable at the same time as the throttle. I thightned the cable up but the slack returns after a lot of stop and go traffic. Again throwing the car into LIMP mode. I'm ordering a new throttle cable soon i'll let u know if that clears that issue to.

 

Where the adaptations cleared (in the DME) after the throttle body was replaced?

http://tis.spaghetticoder.org/s/view.pl?1/04/35/75

Note:
A faulty throttle adjusts the adaptation values stored in the DME control unit. These adaptation values must be reset after the throttle assembly has been replaced.
Clearing adaptation values:
- Connect DIS Tester
- Select vehicle type
- Select "DME Motor Electronics MS42", ne carry out individual brief test
- Continue with bottom right arrow
- The "Fault pattern selection" window appears.
Select "Function selection" (bottom left)
- The "Function and component selection" window appears:
- Select "Service functions"
- Select "Drive"
- Select "Digital Motor Electronics"
- Select "Reset adaptations"
- Select "Test schedule" (bottom left)
- The "Test schedule" window appears. ne Select "Reset adaptations"
- Continue with bottom right arrow
For subsequent procedure, follow DIS instructions.
The new adaptation values are stored in the DME control unit after the engine is started for the first time.

 

Hello, Did replacing throttle cable help?

 

Found the problem in my engine harness. Possibly from chaffing wire harness. And yes the replacing the cable in my car worked.

 

Where was the wire damaged? Near the TB connector?

 

The problem was in the main wire loom from the dme to the junction block on the side of the engine under the intake manifold.

 

Hey new here i have a 2000 bmw 328i and a while back it was running good just throwing a code for a engine coolant temp sensor so I replaced the sensor and the gauge right when u turn the switch to the on position the temp gauge would shoot straight to hot when it***8217;s cold so I pulled off the intake again trying to go threw the sensor wires and went through the whole wire harness and they after putting it back together it threw a code for the coolant sensor and also the p1542 and p1580 and the elm light came on and so did the dsc light and won***8217;t rev over 2k rpm so I cleared the codes and started the car again and the p1542 and p1580 never came back and now it seems like it***8217;s stuck in limp mode how can I get it out off limp mode or what could I check any help would be appreciated