Abs problem

[Aelfwine]

Hey Everyone! I bought a 2002 4runner recently and found a problem. Sometimes when i start the engine the abs, vsc off, trac off light would stay on. Then i would put it in drive, go forwards a bit and press the brakes. I would put it in park again and shut it off, start again and the lights are no longer on. Also whether the lights are on or off, when i almost come to complete stop the abs goes of and the brake pedal becomes soft for a second and then it stops. Can anyone help me? Is this common?

Thank You!

 

[Aelfwine]

Anyone???((

 

[jasonoflivingston]

So, when you are coming to a stop, do you almost stop and then it feels like the abs releases the brakes and the vehicle wants to roll ahead a little causing you to have to hit the brakes harder to make it come to a full stop?

If that sounds like your situation, it could be one of the abs sensors that has gone bad. I had that happen with my Mazda B4000.

I am not as familiar with the traction control systems in the newer third gens so I am not sure if this would work or cause other symptoms, but you could try pulling the fuse for the abs. If your vehicle stops properly after doing so, there is a good chance it is an abs sensor.

J

 

[Aelfwine]

Yes thats exactly what happens. And I did pull the fuse and it stops normally now. This morning the roads were icy and I had to turn my 4x4 on, when it engaged the abs went crazy and the car randomly started braking by itself. Pretty freaky)

 

[jasonoflivingston]

That is very freaky. It did that with the abs fuse pulled? Without that fuse, the abs shouldn't modulate at all. Would it make sense that it was the traction control doing the braking you felt? Abs releases the brakes when they lock up. Traction control would apply braking to redistribute power.

I am assuming the traction control is linked to the abs sensors to get data. If the abs is not working properly, would it get a faulty reading and cause your traction control to think one wheel was standing still and the other was slipping and therefore activate?

I am not familiar enough with these systems to make more than logical guesses here, but it seems to make sense to me. Perhaps someone else with more experience will chime in.

My assumptions aside, it still sounds like it could be a bad sensor. If it is your traction control freaking out and it doesn't do it in two wheel drive, I would be tempted to assume it is one of the sensors on a front wheel as I am imagining that the traction control doesn't use them when in two wheel drive.

Beyond that, I have no idea.

 

[Aelfwine]

That was before i pulled the fuse, sorry for not being clear. After i pulled the fuse everything works fine, 4x4 as well. Well i guess I should get my sensors checked out. Thanks for your help! Might do the andy mod while im at it)

 

[jasonoflivingston]

No problem. I hope you are able to get things sorted.

 

[Aelfwine]

UPDATE: checked my abs sensors with a multimeter and according to the reading they work. Also pulled them out and they were really clean, no gunk or anything. My problem persists! Problem in the wiring? ABS/TRAC computer? As much as I've read how people hate the VSC and ABS on these trucks, I bought it with it not working... I'd like to try it at least and see if I like or not, lol))) So please, more suggestions? Maybe try zero point calibration?

P.S.: When all the lights do stay on, in this case everything is ok and the ABS along with the TRAC/VSC are not working. I lied when I said that its glitching regardless of whether they are on or off.

 

[808Waterman]

Aelfwine,

I know this is an old thread, but resurrecting in hopes you got some answers.

Did you ever get this resolved? I'm having a similar issue. Didn't try pull fuses or anything yet. Just kinda starting to get symptoms with no lights or codes.

Thanks,

 

[BrianK14]

This is often a wheel speed sensor issue. You have one or more going bad, dirty, or not seated properly (often due to rust)