Electronic Thottle Issue

I have a really frustrating issue with my M3.

Last year I started having a problem with the throttle. Every morning when it’s cold the car will start and then immediately drop into limp mode (EML, DSC lights on). The fix is to simply let the engine run for 30 seconds. Stop the engine and then restart. Then all works as it should. The fault doesn’t usually reoccur until the following (cold) morning regardless how many times I use it during the day. It only reoccurs if it is a really cold day and the engine is allowed to get stone cold.

I plugged in a reader and according to INPA the fault is [107: Electric Throttle: Self-Test]. There are no other codes. Essentially it appears to be failing the throttle self test before engine start but only if it’s really cold.

This is definitely temperature related as this problem did not occur even once throughout the summer. Now we have had a couple of cold days (say less than 4 degrees) and its doing it again. Apart from this the car works absolutely perfectly. Has anyone the slightest idea what this might be? I’m guessing that something is measuring out of spec when it’s very cold. Given that it will pass after the engine has been allowed to run for only 30 secs I assume it must be something directly connected to the cylinder head or the block itself because I doubt there is any measurable change in the temp of the ancillaries after such a short time.

All ideas welcomed.

Ralph

One of your potentiometers is failing or already failed. There's 3 of them. One on the gas pedal, one by the oil filter and one under the intake manifold. You need somebody with software, I know GT1 works, to have the faults read and tell you which one is failing. Take it to an Indy shop if nobody has software.

I did wonder if it mght be linked to the TPS. From a quick scan on google it seems that the easy to get at one at the front of the engine is the most likely culprit.

I note the TPS part no. is the same for the oil filter position and under the intake manifold. I think I'll buy a new one and swap it out starting with the one by the oil filter.

R

Yes it's the same part number. The one under the intake manifold is a b1tch to get too. Start with the oil filter one and the gas pedal. They are fvcking easy to fix.