ABS kicks on when it shouldn’t, possible AWD issues too

[RichCresci]

2006 Mountaineer 4.0 awd

So I left the car wash the other day after getting the under body wash and when I hit the brakes the abs kicked on for a little. I didn’t think much and kept on driving.

2 days and 100 miles of normal driving later, every time I hit the brakes slightly more than usual, the abs kicks in. When I turn right it feels like the truck is in 4wd. I’m assuming I lost a wheel sensor but it seems really coincidental that I just went to the car wash. I visually checked all the sensors, they’re still there. Any ideas? Also, is there a way to trouble shoot a wheel sensor without an abs computer?

thanks

 

[J_C]

Given the circumstances I would inspect the ABS sensor cables, unplug them at the connectors and examine the contacts... maybe water + xyz made it into the connectors or is causing a short against the frame or knuckle.

You can read the speed sensors with Forscan app, through an ELM327 dongle and a connected phone, tablet, or laptop. You can also log the data while driving and save to a file for more convenience and safety than trying to watch the device while driving.

Recording wheel sensors - FORScan forum

 

[RichCresci]

I visually inspected all the wheel sensor connections. No issues there. I ordered the dongle. Stay tuned for updates.

 

[RichCresci]

Fiddled with the dongle yesterday and the ForScan app. I pulled the codes and got

C1155-E0 Left Front wheel speed sensor missing
C1234-20 Right Front Wheel speed sensor missing
C1145-20 Right Front wheel speed sensor circuit failure

When the issue first appeared I disconnected both front wheel sensors to inspect the connections, so I believe that's why I have both front sensors missing. However, the C1145-20 is interesting. When all my sensors are plugged in I still don't get any warning lights. I'm going to do some more serious investigating today, but I'm starting to think this could be a wiring issue to the the right front wheel, or a bad hub.

Can I clear the codes through forscan? I could seem to figure out how to do that. I'd like to reset the codes and see what new codes pop up.

 

[RichCresci]

Problem solved! It was a bad front passenger wheel bearing. I’m really surprised as it didn’t make any noise or issues in the steering.

 

[J_C]

Good to know it's fixed. The theory I have is that as the bearing starts to wear out, it spits out greasy metal particles that foul the sensor ring or get slung onto the sensor itself.

 

[RichCresci]

The wheel had significant play in it which was extremely obvious when I jacked the truck up. However no stereotypical wheel bearing symptoms from the cab.

Interestingly enough, I had that tire off about 1,000 miles and 4 weeks ago and specifically checked for wheel bearing play and found nothing. So it failed very quickly with minimal evidence.