ABS lt on after diy work

[peter B]

07 Ranger, 2wd. I recently replaced front brakes, pads & rotors and then the ABS Light comes on intermittently ever since. Maybe the magnetic sensor that reads the inside of the rotor is dirty? I tried to remove one to look and it wouldn't let go. The former owner spent time in salt water but the sensor should just pull out once the bolt is removed? I can tell ABS isn't working, otherwise brakes stop the truck .

 

[Dirtman]

In a perfect world yes the sensor should come out after removing the bolt. But in real life thats not how it works. They are almost always seized into the hole.

If you can get a scanner that reads ABS codes (forscan does) you can see which sensor is causing the problem. First check the wire all the way up and the connection. It's not uncommon for a wire to rub through or connection to corrode. If that all looks good pull the rotor back off and inspect the tone ring for damage, sometimes even a brand new rotor will have a tooth missing. If that all looks good you may be stuck replacing the sensor as removing it if its seized, even to inspect/clean it often means destroying it in the process.

 

[franklin2]

This is what I got from the manual. What is a red flag for me is the "tone ring (part of the front rotor)". Did the new rotors have the tone ring and was it properly manufactured if they did?


Anti-Lock Control

SECTION 206-09: Vehicle Dynamic Systems	2007 Ranger Workshop Manual
DESCRIPTION AND OPERATION	Procedure revision date: 05/01/2006

Anti-Lock Control
The anti-lock control system consists of the following components:

• ABS module
• Front wheel speed sensor
• Front wheel speed sensor tone ring (part of the front rotor in Rear Wheel Drive (RWD) vehicles, part of the front wheel bearing assembly in Four-Wheel Drive (4WD) vehicles)
• Hydraulic Control Unit (HCU)
• Rear wheel speed sensor (located in the center top position on the rear axle assembly)
• Rear wheel speed sensor tone ring (part of the rear differential)

The ABS prevents wheel lockup by monitoring the wheel speed sensors and actuating the HCU modulating the brake pressure to prevent wheel lockup. By preventing the wheels from locking up, the driver is able to maintain steering control and stop in the shortest possible distance under most conditions.

 

[sgtsandman]

The sensor or the wires to the sensor could be a possibility but I would make sure you got the correct rotors first.

Also, I’m moving this to the brakes sub-forum since subject content matches better there than the 2019+ Ranger forum.

 

[Dirtman]

I was going to suggest wrong rotors, but the ABS light wouldn't be intermittent if they were flat out missing the tone rings. It would be constantly pissed off.

Plus 4x4 rotors are completely different, won't even fit, and there's really no other option for a rotor that would actually fit a 2007 and have the wrong, or no tone ring that I am aware of. Like I said they could be the correct rotors and just have bad tone rings out of the box though.

 

[pjtoledo]

2wd tone rings are just a piece of stamped metal, with a lot of slots. they press onto the hub.
as such the height can be adjusted by carefully prying on them a bit.
you will need something that can get under the ring and contact it at the hub.
they bend easily. they also are easy to straighten out.

you can check the ABS sensor with a digital volt meter, (and old style needle one works better for this)
use the resistance setting, or lowest AC, and spin the wheel at a constant speed looking for dropouts.

a standard procedure on any intermittent electrical issue is to reseat the connector several times to scrape away corrosion.

edit: loose bearings will allow the hub/tone ring to move around, check 'em.