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mistertripps
11-17-2007, 11:56 PM
Alright gear-heads, I need your experience. On the way home from the winery this afternoon, we started getting the ASC warning light flashing and the rear brakes engaging whenever we got up close to 80 MPH or hit a pretty good dip in the road. I'd have to back off the accelerator to get it to shut off.

Some things to consider - (1) we just installed new wheels this week changing from 16" to 17", (2) this did not happen on the drive up, even though I was driving in excess of....well, let's just say a bit North of 80 :), (3) we took the car through some pretty winding roads and I did my best to keep up with Stig even though I was in a wagon and (4) when Alan (GCR) checked the car out last week, he said we would need new control arm bushings soon.

Is this possibly related to a suspension issue or do you think it is a wheel speed sensor going bad? We'll take it in for a check-up, but I thought I'd get some opinions first. Is this something urgent that would keep us from driving under normal conditions, or can it wait a bit?

88e28
11-18-2007, 12:50 AM
First have Alan check it out if it costs money take your Gift Certificate to the shop you won at.

mistertripps
11-18-2007, 01:03 AM
First have Alan check it out if it costs money take your Gift Certificate to the shop you won at.

Ha! I'd already thought of that!

GCR
11-18-2007, 01:35 AM
Ha! I'd already thought of that!

Tim,

are the tire sizes the same on all 4 wheels? I need to check the system out for you & see what (if any) fault codes we find. Also check rear tire pressures. If you have a low tire on one side, it will intervene. pm me with any more questions.

Alan

GCR
11-18-2007, 02:40 AM
Saturday nite & the brain moves slowly. Been thinking about your problem. I've seen steering angle sensors get a little goofy & cause similar issues too. DSC thinks that there is excessive slip angle if the SAS is out of calibration or defective & will try to correct a slide by braking the outside wheel. Bring her in when you can & I'll run some live data tests on the system. The system activating when hitting bumps also stirs another thought in my aging memory banks. I had an E46 330i do similar things that I traced to a wiring harness rubbing in the engine bay........

Alan.

mistertripps
11-18-2007, 03:49 AM
Thanks Alan. We'll definitely bring it in. Funny thing is that it was happening on 400 going straight. It just didn't want me going 80.

The tire sizes on the front are 235-45/17 and the rear are 245-40/17. It ran great on the way up to Cumming and then on to the Winery. It was only after we got back on the Highway that it started acting up.

GCR
11-18-2007, 04:09 AM
Thanks Alan. We'll definitely bring it in. Funny thing is that it was happening on 400 going straight. It just didn't want me going 80.

The tire sizes on the front are 235-45/17 and the rear are 245-40/17. It ran great on the way up to Cumming and then on to the Winery. It was only after we got back on the Highway that it started acting up.


Smart car!:) Going 80 on 400 isn't a great idea lately.........

mistertripps
11-18-2007, 04:23 AM
Yeah, yeah. But every once in a while you just need to pull out and get around someone!!

Smart car!:) Going 80 on 400 isn't a great idea lately.........