abs fault

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
9,962
Likes
180
Points
63
Location
St-Hyacinthe, Quebec, Canada
#16
If light goes out, you now know you have bad front bearings/hubs/reluctor. They can only be bought as a unit, and cost quite a bit. SO you need to be sure which one is faulting, and usually, you can only acheive that with a abs capable scan tool/dongle/interface.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
9,962
Likes
180
Points
63
Location
St-Hyacinthe, Quebec, Canada
#17
So I think I just beat this dead dog enough. Once you give me a code, I will go into overdrive for you.

 

Tag 43

Jr. Member
Joined
Apr 29, 2007
Messages
39
Likes
0
Points
6
#18
If, you have a chassis code puller, would really help here. Plz post that.

If you have erratic sensor codes, swapping just the sensor/s will do nothing if reluctor is shot.

It is normal when abs light is on to have no pulsating at wheel brake, abs module has effectively just gone in a form of limp in mode, which is just like removing the fuse. This indicates good function of the ABS unit.

Honestly, if you can't pull the codes from the ABS/chassis modules, I don't know where to start with helping you. I can provide all the wiring's, every flow chart I have in my arsenal, you might be chasing something that a bore-scope could see.

To pull chassis codes, you will require a different code puller than your down cheap walmart thing. They actually do have one, but it is close to 200something dollars, you could do way better by buying some sort of tech 2 clone off amazone or aliblabla.
Ok I was able to get some codes. At least it what I think I need. They are as follows;. C0055, C0040, C0035.
 

Tag 43

Jr. Member
Joined
Apr 29, 2007
Messages
39
Likes
0
Points
6
#20
So, are you saying the wheel bearings are bad. The new sensors I put on are bad. Or what. I am lost at this point.
 
Joined
Apr 9, 2014
Messages
15
Likes
0
Points
1
#21
Ok I was able to get some codes. At least it what I think I need. They are as follows;. C0055, C0040, C0035.
C0055 = Rear Wheel Speed Sensor Circuit.
C0040 = Right Front Wheel Speed Sensor Circuit
C0035 = Left Front Wheel Speed Sensor Circuit

Since you've already changed both front speed sensors with no change in your problem, I doubt your problem is the sensors. You need to check the condition of the reluctor wheels as advised earlier.

The rear speed sensor is in the transfer case (4WD).

As a DIY that knows enough to be dangerous....at this point, I would proceed as follows.

1. Inspect the reluctor wheels at the front wheels for dirt/corrosion. Clean them off with a soft wire brush. Inspect them for damage.

2. Locate and remove the speed sensor in the transfer case. Inspect the end and remove any foreign matter. It may appear like fine, black dust.

3. Inspect the wire harnesses upstream of the speed sensor connectors for damage.

4. Road test.

Side question 1: Is the speedometer acting weird?

I think it's odd that you get all three trouble codes at once if it's just the speed sensors/reluctors. Especially if the problem is intermittent as you initially stated. However, do the above and report back.

Side question 2: Does the BRAKE warning light come on with the ABS warning light?
 

Tag 43

Jr. Member
Joined
Apr 29, 2007
Messages
39
Likes
0
Points
6
#22
C0055 = Rear Wheel Speed Sensor Circuit.
C0040 = Right Front Wheel Speed Sensor Circuit
C0035 = Left Front Wheel Speed Sensor Circuit

Since you've already changed both front speed sensors with no change in your problem, I doubt your problem is the sensors. You need to check the condition of the reluctor wheels as advised earlier.

The rear speed sensor is in the transfer case (4WD).

As a DIY that knows enough to be dangerous....at this point, I would proceed as follows.

1. Inspect the reluctor wheels at the front wheels for dirt/corrosion. Clean them off with a soft wire brush. Inspect them for damage.

2. Locate and remove the speed sensor in the transfer case. Inspect the end and remove any foreign matter. It may appear like fine, black dust.

3. Inspect the wire harnesses upstream of the speed sensor connectors for damage.

4. Road test.

Side question 1: Is the speedometer acting weird?

I think it's odd that you get all three trouble codes at once if it's just the speed sensors/reluctors. Especially if the problem is intermittent as you initially stated. However, do the above and report back.

Side question 2: Does the BRAKE warning light come on with the ABS warning light?
The speedometer works fine. And there is no brake light at any time.

One more question? What is the easiest and safest way to remove the new sensors so I can clean and inspect the reluctor ( which is built in the back of the bearing hub) if I am correct. Thank you for all your help....
 
Joined
Aug 28, 2007
Messages
4,799
Likes
26
Points
48
#23
Pulling the connector out of the ABS unit and having the pinouts of that connector from a manual, each sensor has two wires. Connecting an ohmmeter to those two pins should show continuity. Some of the sensors may have more than one connector, one cable connected to another and even another one as well.

Corrosion gets into those connectors so do not have continuity and thus no pulses into the ABS modules. Replacing the sensors does not cure this problem, new sensor with a new connector and nice shiny pins is good, but what you are plugging it into is not.

On several vehicles, got rid of those worthless connectors and soldered the wires with good insulation. Is not like you are changing sensors every five minutes. Said this a long time ago when first became an engineer, best connector is no connector, strictly for convenience of replacing a component but also the major problem.