ABS issues

[RHYSF00]

So under normal braking not heavy no matter the weather or surface my abs will activate the brake like 80% of the time. i have had a garage look at it and they cant seee anything wrong. It even happens alot in stop and go traffic. if anyone have any ideas on how to fix it or where to even start looking it be much helpful. 

For those that need to know i have a 2004 corolla vvti t3 3dr. 

[Stivino]

It could be a split reluctor.  Sometimes the split can be very hard to see.

[RHYSF00]

What a reluctor

[Stivino]

reluctor

[RHYSF00]

So i looked at drawings and cant seem to see that part on my model

[flash22]

i would do the paper clip test and see if the ABS has any codes stored - you do this by linking 2 pins on the obd2 connector, turn the ignition on and count the flashes, that should give you a 2-digit code

 

 

on the rear the reluctor is part of the wheel bearing and the sensor is on the back of the hub

on the front, the ring is part of the CV joint

[RHYSF00]

Just now, flash22 said:

i would do the paper clip test and see if the ABS has any codes stored - you do this by linking 2 pins on the obd2 connector, turn the ignition on and count the flashes, that should give you a 2-digit code

 

 

on the rear the reluctor is part of the wheel bearing and the sensor is on the back of the hub

on the front, the ring is part of the CV joint

im still confused

[flash22]

10 minutes ago, RHYSF00 said:

im still confused

pic added above

 

on each wheel you have a sensor, on the rear you have a ring built into the bearing this is made up of little segments that the sensor counts, on the front you have a ring on the drive shaft this has teeth the sensor counts

[RHYSF00]

4 hours ago, Stivino said:

reluctor

 

5 minutes ago, flash22 said:

pic added above

 

on each wheel you have a sensor, on the rear you have a ring built into the bearing this is made up of little segments that the sensor counts, on the front you have a ring on the drive shaft this has teeth the sensor counts

Ok. Think i understand 

[RHYSF00]

On 10/11/2022 at 12:32 PM, flash22 said:

pic added above

 

on each wheel you have a sensor, on the rear you have a ring built into the bearing this is made up of little segments that the sensor counts, on the front you have a ring on the drive shaft this has teeth the sensor counts

this??

[flash22]

Not quite

the outer cv joints has the ring (silver ring on the cv joint as below)

eg. https://vehicleaftermarket.skf.com/uk/en/products/VKJA3513

Being front-wheel drive (FWD) it uses a steering knuckle (red arrow is the abs sensor)

Click to enlarge

 

On the rear - you have a segmented magnet as part of the bearing with a sensor pointing at it, usually supplied as a complete rear hub assembly

Click to enlarge - in this pic using a special magnetic field card you can see the magnetic segments

https://vehicleaftermarket.skf.com/uk/en/products?market=eu&l=en&vehicleid=eu0002-16374&tab=tab_1_automotive

 

you need to do the above paper clip test to find the issue or someone with a scan tool to test drive the car and look at the wheel speed sensor data

The rear sensors/bearings are prone to water ingress with age, this makes the sensors fail or go intermittent or the magnetic rings crack up

 

 

 

 

[RHYSF00]

1 hour ago, flash22 said:

Not quite

the outer cv joints has the ring (silver ring on the cv joint as below)

eg. https://vehicleaftermarket.skf.com/uk/en/products/VKJA3513

Being front-wheel drive (FWD) it uses a steering knuckle (red arrow is the abs sensor)

Click to enlarge

 

On the rear - you have a segmented magnet as part of the bearing with a sensor pointing at it, usually supplied as a complete rear hub assembly

Click to enlarge - in this pic using a special magnetic field card you can see the magnetic segments

https://vehicleaftermarket.skf.com/uk/en/products?market=eu&l=en&vehicleid=eu0002-16374&tab=tab_1_automotive

 

you need to do the above paper clip test to find the issue or someone with a scan tool to test drive the car and look at the wheel speed sensor data

The rear sensors/bearings are prone to water ingress with age, this makes the sensors fail or go intermittent or the magnetic rings crack up

 

 

 

 

Is there an obd scanner thst you can recommend 

[flash22]

Not really as there are so many on the market, you will need one that does live abs data, the paper clip test is free !!

[RHYSF00]

7 minutes ago, flash22 said:

Not really as there are so many on the market, you will need one that does live abs data, the paper clip test is free !!

How safe is it

[RHYSF00]

On 10/11/2022 at 12:16 PM, flash22 said:

i would do the paper clip test and see if the ABS has any codes stored - you do this by linking 2 pins on the obd2 connector, turn the ignition on and count the flashes, that should give you a 2-digit code

 

 

on the rear the reluctor is part of the wheel bearing and the sensor is on the back of the hub

on the front, the ring is part of the CV joint

 

[RHYSF00]

 

[flash22]

link in - ignition on (do not start)

[RHYSF00]

Just now, flash22 said:

link in - ignition on (do not start)

thought someone said start. ok give me 5 mins

[RHYSF00]

Got video. I upload in a min

[RHYSF00]

 

 

 

[flash22]

Looks like it's does like the test - is the driver's door open or shut ?

[RHYSF00]

1 minute ago, flash22 said:

Looks like it's does like the test - is the driver's door open or shut ?

open

[flash22]

try it closed, if not there is another method

the abs should stay solid then start to flash, Ignition off - fit the link - Ignition on (do not start) - with the driver's door closed

[RHYSF00]

9 minutes ago, flash22 said:

try it closed, if not there is another method

the abs should stay solid then start to flash, Ignition off - fit the link - Ignition on (do not start) - with the driver's door closed

what is it  i ment to look for?

 

[flash22]

Look at the diagram !!

Original

2nd method