ABS / Traction Control / Speedo Dropping

335i_GP · 10-30-2018, 07:44 AM

Hey All,

I believe my wheel speed sensor will be the culprit but figured I would toss a post up while I'm sitting at work to see if anyone agrees or disagrees.

2008 335i

Friday I was driving and had a blow out on my 19" Wheels (Driver side rear) My run flats did their job and I was able to make the 20 minutes drive back to work.. the inside of the tire was destroyed.. but did not damage the wheel.

I took a coworkers car home and snagged one of my factory 18" wheels and threw it on just so I could make it home. I drove home and everything was fine. It sat in the garage until Sunday, and I had to run into town before I changed out all the wheels to the factory setup. So all in all I would estimate maybe 15-20 miles I drove with an 18" stock wheel on the drivers side rear while all the others were my 19" summer wheels.

Monday I drove to work like normal and didn't notice any issues, and even on my lunch break I ran to the store and didn't notice any issues.. but on my way home I noticed my speedo drop to 0 and come right back up.. around this time I noticed my traction control light was on as well as my ABS light. It drove fine still. Drove home and parked it in the garage.

This morning on my way in to work, same thing was happening as mentioned above. Speedo would drop to 0 but come right back up.. same lights coming on. Except this time since it was dark I noticed my headlights would flicker when this happened.. not sure why the headlights would flicker but who knows.

I'm thinking the wheel speed sensor got messed up either by running a different size wheel for those 15-20 miles, or a wire was damaged when I had my blowout and its intermittently causing an issue.

Thoughts? Happy Tuesday!

bluewater328 · 10-30-2018, 12:50 PM

Sounds like a separate issue with power delivery to the system. Trifecta can actually show up due low battery or alternator power. You're not helping things with wheels that may not weigh the same, throwing off the traction, but I'm not sure you can kill headlights with that. Also figure that your stock 18s may still be roughly the same diameter overall, so its only the uneven spun weight.

10-30-2018, 07:44 AM	#1
335i_GP Private 4 Rep 61 Posts Drives: 2009 335i Join Date: Jan 2018 Location: Canfield, Ohio iTrader: (0)	ABS / Traction Control / Speedo Dropping Hey All, I believe my wheel speed sensor will be the culprit but figured I would toss a post up while I'm sitting at work to see if anyone agrees or disagrees. 2008 335i Friday I was driving and had a blow out on my 19" Wheels (Driver side rear) My run flats did their job and I was able to make the 20 minutes drive back to work.. the inside of the tire was destroyed.. but did not damage the wheel. I took a coworkers car home and snagged one of my factory 18" wheels and threw it on just so I could make it home. I drove home and everything was fine. It sat in the garage until Sunday, and I had to run into town before I changed out all the wheels to the factory setup. So all in all I would estimate maybe 15-20 miles I drove with an 18" stock wheel on the drivers side rear while all the others were my 19" summer wheels. Monday I drove to work like normal and didn't notice any issues, and even on my lunch break I ran to the store and didn't notice any issues.. but on my way home I noticed my speedo drop to 0 and come right back up.. around this time I noticed my traction control light was on as well as my ABS light. It drove fine still. Drove home and parked it in the garage. This morning on my way in to work, same thing was happening as mentioned above. Speedo would drop to 0 but come right back up.. same lights coming on. Except this time since it was dark I noticed my headlights would flicker when this happened.. not sure why the headlights would flicker but who knows. I'm thinking the wheel speed sensor got messed up either by running a different size wheel for those 15-20 miles, or a wire was damaged when I had my blowout and its intermittently causing an issue. Thoughts? Happy Tuesday! __________________ FBO 2008 335i - Totaled 2009 335i - DCI, Exhaust, Cobb Tuned, Cosmetic Stuff
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10-30-2018, 12:50 PM	#2
bluewater328 Colonel 645 Rep 2,098 Posts Drives: 2011 bluewater 328i LCI sedan Join Date: Aug 2010 Location: Hawaii iTrader: (0)	Sounds like a separate issue with power delivery to the system. Trifecta can actually show up due low battery or alternator power. You're not helping things with wheels that may not weigh the same, throwing off the traction, but I'm not sure you can kill headlights with that. Also figure that your stock 18s may still be roughly the same diameter overall, so its only the uneven spun weight.
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