Cant drive 09 DTS on dirt roads

cadillac
dts

#1

Recently, some long-term roadwork has begun in my neighborhood. They’re tearing up the roads to install water pipes and now many of the roads are dirt. I believe the second time I drove down one of these dirt patches that was at least 50 feet, I had a chime go off in my Caddy. Trac light and brake lights came on in dash. The display read service brakes, service stabilitrak, and service traction control. The moment i hit pavement, they went off and back to normal. For about a week everytime I hit this patch of dirt road, these lights popped on and messages were displayed. They always turned back off immediately after hitting pavement. After the first week these warnings started popping on at stoplights (on pavement) as well. I noticed if i would let the car roll just a touch, they would go off. I recently purchased aftermarket wheels and upon install I looked around the hubs for anything odd, and everything looked fine to me. Three days went by with no chimes and I though “hey I magically fixed it!”. I was wrong. Warnings came back on dirt, and at stops. Seems to be slowly becoming more frequent. Any ideas Car Talk Nation?


#2

Cadillacs were never mean for off-roading. The wheel speed sensors are high resolution and they are seeing odd variations in individual wheel speed from the uneven road surface. Avoid this road, use a different vehicle until constructions is completed or simply live with the false fault indication.


#3

This makes sense but why am I also seeing this when stopped on pavement?


#4

I would be interested to know what the fault codes are in the ABS. I wonder if a wheel bearing is going bad? The left front seems to always be the first to fail.


#5

Dirt may have gotten into the ABS sensor. The fix is to remove the sensor if possible and clean it. But many GM cars have the ABS sensor integrated into the hub. The fix is to let it clean itself or replace the entire hub if the sensor cannot be removed.