ABS Light On, But Turned Off for A Min - 04 Tundra

The ABS light was on in the truck's instrument display when I bought it (178k) which I didn't mind so much. Screw it, no ABS. Soon after I brought it home I flushed/bled all 4 brakes which greatly improved the braking feel. Things have been going well with the truck.

The other night I was braking downhill around 3-5mph and some shit happened. The ABS light turned off and I heard a weird hissing/churning noise, something that can be best described as "cccchhhhh" and definitely sounded hydraulic. The vehicle still stopped fine at the bottom of the downhill, ABS light was off.

When I started driving again on flat ground the ABS light turned back on after about a minute or so. What happened here?

 

Sounds like your ABS decided it wanted to work for a minute. Seems like most people just pull both ABS fuses to disable the system entirely. If you're not worried about having or using ABS then this is the easiest and cheapest way. I can't tell you where the fuses are though as my truck doesn't have ABS anyway.

Be sure that you pull both fuses though or it will not disable completely.

You may be able to search around the forum and find some other posts about this.

 

Have you tried engaging 4wd while the light is on? Some vehicles (not sure about tundras and especially not sure about first gens) which have abs issues will not be able to engage 4wd…..

 

Are you sure what you're hearing isn't your ABS activating? Do you feel anything unusual in the brake pedal when it occurs?

 

I might just do that so I don't have to worry about random ABS engagement. But if it's fixable I'd like to fix it

 

Yep, 4wd works totally fine.

 

I'm not sure of what I'm hearing but definitely no brake pedal pulse typical of ABS engagement.

 

So I redid all of my brakes with Powerstop Z36 full set. Fully redid them.
Front rotors, calipers, and pads.
Rear drums, shoes, and one wheel cylinder.
Braking is much better now overall, drum brakes are properly adjusted, parking brake works great.

The ABS light is now sporadically turning off and on. Sometimes no error light for the whole drive, sometimes it turns back on at random, sometimes ABS will activate for no reason, sometimes I'll have a hissing mechanical/hydraulic "kkhhh" sound (not grinding noise, sounds like some mechanism trying to activate) from the brakes and will lose some stopping power until I pump the brake pedal again to get normal braking.

I'd prefer not to disable ABS since I want it for rainy days, and it seems like my ABS is on the verge of being ok? Does anyone know WTF is going on?

 

Perhaps there's a short somewhere in the system and the wiring needs replaced, that could explain the sporadic ABS light illumination. Your ABS light shouldn't be coming on if the system is working okay. It won't come on when ABS properly engages.

If you have a OBD-II scan tool that reads ABS codes, it might tell you the stored code that was causing the illumination. A good scan tool can also tell you the vehicle's speed, and each wheel's ABS sensor speed. My scan tool reads out the speed of each wheel and they're equal with the vehicle's speed.

If you DON'T have an ABS capable scan tool, you can can use a bare wire, paperclip or something similar to get the ABS code. If you can stop and do this as soon as the ABS light illuminates that would be great.

You will need to connect two of the connectors inside of the OBD-II port above the gas pedal to get a code. #4 and #13.



Once you have the connection made, switch the ignition on. The cruise control light should be blinking rapidly. After a few seconds, the ABS light will start flashing. Count these flashes, there will be two sets of them. (i.e. flash-flash-flash pause flash-flash-flash-flash = 34)

Here's a list of all the DTCs on the ABS system: https://www.toyotaguru.us/sequoia-2007-repair/dtc-chart-of-abs-system.html

If you got code 34 for instance, that would be your left rear wheel speed sensor.

 

Whoa. What an incredibly helpful answer. I'll definitely be trying this.

 

Oh wow. That's like pulling codes on an OBD I system.