Automatic Transmission Warning Light
 

I replaced my expansion tank last night and after I completed the job I ran the car for about half an hour ticking over outside the garage to get the car up to temp to check for leaks when the radiator system was pressurised.

I left off the air filter housing and Mass Airflow Sensor whilst I was running the car so I could get a better view of any leakage.

I noticed afterwards that there was a yellow warning light on the dash. it is a little yellow circle with an exclamation mark in the middle. I looked in the manual and it states Automatic Transmission Warning Light.

Is this related to what I was doing? Will this dissappear on its own or will I need to reset it?

What year is your X3 and how many miles do you have on it?

You should get the codes checked. I had that light too and it was transmission related. Although, when I'd turn off the car and let it rest for a few minutes it would go away when I restarted it.

So get the codes checked to see what they are for. They should be stored even of the light goes off.

Edit: Just saw in your signature that you have a 2004 2.5 like me. I'm actually getting the tranny checked this week because it has really killed my gas mileage. The tranny light goes away but the Check Engine Light is now on and won't go away. So i figured I'd better get it checked. I just hope it's not going to break the bank to fix it!

The error warning light must have been becuse I was running the car without the MAF sensor connected. once everything was put back together all the warning lights dissapeared and have not come back on since. that was 2 months ago!