1997 e39 ASC light

[Magus528]

Hello Everyone

I am a long time lurker, first time poster. There are many people on this board who are a lot more knowlegable than me about this issue so I thought I would ask for help/ opinion. First things first. I have purchased a 1997 528 recently. The person that I purchased this form informed me that the car had gone into limp mode a few times when it was very cold and he did not remember if it also happened if it rained.

After doing some research on this board, it pretty much boiled down to either the ABS module or the Speed sensors.
I have downloaded and installed INPA on my laptop running win10 as well as purchasing the CReader CRP123. I have all of the proper cables or the ODB and 20 pin connector under the hood.

I scanned the car and it informed me that the left front speed sensor was bad. It also threw a code for a servomotor choke valve.

My questions. Can one bad speed sensor cause the ASC light to come on and not turn off and affect the traction control in such a way that the trans goes into limp mode? Cant a servomotor choke value cause these issues as well?

The other thing is, as I looked under the hood, what I thought was the ABS module was pretty thin


This is not my picture, but mine looks like thisIt appears that This is not my ABS module and that my actual ABS module is actually under the glove box?
If it is under the glove box, could it still go bad? If I purchased another off of ebay, would I still have to have it reprogrammed for my car?

Thank You

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I also wanted to note that the Traction control light is the only one that is on.

[philly98540]

Likely the choke valve. IF it does not successfully perform the startup check function, the traction light will stay on. Have someone turn the key to position 2 while you watch the operation of the choke valve. It should cycle closed then back open as a pre start check.

[Magus528]

Likely the choke valve. IF it does not successfully perform the startup check function, the traction light will stay on. Have someone turn the key to position 2 while you watch the operation of the choke valve. It should cycle closed then back open as a pre start check.

So if there is an issue with the servo motor of the choke valve, this can cause the ASC light to stay on?
My next stupid question is where would I look for the choke valve movement?

[philly98540]

Yes.

It's part #1 on this diagram.

http://www.realoem.com/bmw/enUS/show...diagId=13_0409

Basically, the car automatically performs a pre drive check to ensure this secondary throttle valve operates properly. The secondary throttle valve is used to reduce engine power when the wheels start to spin, like in snow, etc. It's part of the ASC system, so ifs is not working right, the ASC light stays on to let you know its not working right.

[Magus528]

THANK YOU philly98540

[Magus528]

I have one more question. I had someone turn the key to the second position. I was able to hear a clicking and a sound but I did not see any movement. Am I supposed to see something move?

[philly98540]

Follow the actuator cable to the throttle. Watch there. Should rotate about 90 degrees.

[Magus528]

Ahhh...I was in the right area and there was NO movement at all. But, it there was no movement of the actuator cable, that means that the throttle is no the issue but the actuator cable...this seems where the movement was coming from? I do have part that you pointed out...part #1 on its way.

[philly98540]

If no movement, you likely need the actuator not the throttle. Test the throttle for binding first by manually rorating it. If it rotates, and is not binding, then it's likely the actuator that is not working.

[Magus528]

The Throttle is not binding at all. I can manually rotate it. So, the actuator..hmmm...looks like I am on a hunt for an actuator.

[philly98540]

Get the part number off of it and search e-bay. There are usually a few on there. They are expensive new from BMW.

[golfgod]

The Throttle is not binding at all. I can manually rotate it. So, the actuator..hmmm...looks like I am on a hunt for an actuator.

You could take it one step further before you buy the actuator and put your meter on the connector to see if it throws voltage...it is a solenoid, so if there is voltage there during the "pre-start" then yes you have a bad actuator...if not, then you need to investigate the dme

[Magus528]

So, I tested the actuator. It feels like the actuator is doing something. I felt it on the bottom where the throttle cable goes in. It feels like something is moving inside or at least trying to move inside, but the cable does not move. Is it possible that the cable some how came loose? I noticed the two screw that hold the actuator are somewhat loose.

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You could take it one step further before you buy the actuator and put your meter on the connector to see if it throws voltage...it is a solenoid, so if there is voltage there during the "pre-start" then yes you have a bad actuator...if not, then you need to investigate the dme

I have to admit. I dont know how to use a multi meter. Something I have to remedy.

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Get the part number off of it and search e-bay. There are usually a few on there. They are expensive new from BMW.

Tell me about it. $350+ from BMW Picked one up for $30 on ebay.

[golfgod]

So, I tested the actuator. It feels like the actuator is doing something. I felt it on the bottom where the throttle cable goes in. It feels like something is moving inside or at least trying to move inside, but the cable does not move. Is it possible that the cable some how came loose? I noticed the two screw that hold the actuator are somewhat loose. - - - Updated - - - I have to admit. I dont know how to use a multi meter. Something I have to remedy. - - - Updated - - - Tell me about it. $350+ from BMW Picked one up for $30 on ebay.

Take the intake boot off so you can SEE the throttle body flapper move when you out the key in position 2...obviously you'll need to have someone else turn the key while you look

[Magus528]

I wanted to report back. Again a big THANK YOU to all that helped. It was the throttle actuator. I popped it in today. it took all of half hr...the ASC button works as designed and the traction control light is now off. The code reader that found it in the first place was the Creader CRP123. $150 bucks plus the 20 or so bucks for the 20 pin connector. Paid for itself already.

[philly98540]

Awesome! Glad that was it!

[m735is]

Have you scanned the car again after the replacement? Does the left front speed sensor still show as being bad? Just curious.

[Magus528]

I did not scan the car again. I will do it tonight. I was just so happy about getting that damn light to go off, I didnt even think about it.