Slip Indicator Help

[AZPartsGuy]

Hey fellas,

Lifted my '01 SR5 2" with the Tundra/906 setup and now I'm having an issue with the Slip Indicator. I am having a very reproduceable issue where in AWD mode I accelerate from a dead stop and the slip indicator light will come on, the engine will reduce power, and it makes an annoying springy noise on my brake pedal. No VSC/ATRAC/ABS lights will come on, just the one light:

This will not happen in 2wd. I have tested it several times and 3/5 starts from a stop it will happen in 4wd, but not 2wd.

I have recalibrated VSC system per Mike Thomson's blog post on the subject twice to no avail.

I have searched high and low all over the forums and possible causes I have come up with are:

• Tires (upgraded to 265/75/16)
• Stretched Wheel Speed Sensor wires
• VSC Calibration

I couldn't pull any codes with my code reader, but I don't think the ECU is going to document these types of codes for a generic reader and I may need a Service Reader to pull the more in-depth info. The truck also may still be cycling after the shop pulled the battery cable.

Any ideas? Thank you.

 

[gamefreakgc]

That "springy" sensation is your ABS. For some reason, the ECU thinks that a wheel is slipping so it's cutting power to the engine and brakes so keep you from locking up the brakes and losing control. It's not your tires.

Easiest thing to do is remove each ABS sensor and check the ABS ring by looking through the opening in the axle. You'll find the black, ABS sensor right behind each wheel hub (has an obvious wiring running off it, not the brake lines) and easily comes off with a single 10mm bolt. Once off, clean off the magnets on the underside of the sensor - that can also get a bad reading. Then jack up the tire and spin it while looking into the axle housing through the hole and inspect the ring below, it looks like a gear. There should be no "teeth" missing or contaminants. Replace the sensor after cleaning if all looks good.

For the rear tires, you'll just need to jack up the entire rear end, put your key in to "ON" and shift to neutral. Be sure to chock the front tires though since there's no brakes on at that point and you don't want your 4Runner rolling away and smashing you in the process.

Once you've checked and cleaned all 4 sensors, give it another try doing the same thing you did before. If you see anything out of place or something wrong, post up a photo if you can.

 

[AZPartsGuy]

I will check these out on Sunday when I have time and I'll report back what I find. Thank you for the help.

Does anyone happen to know why, if for example, the front sensors would not trip while in 2wd but WILL trip while in 4wd? I would assume the vehicle is taking data from all 4 sensors regardless of the mode.

 

[gamefreakgc]

I will check these out on Sunday when I have time and I'll report back what I find. Thank you for the help.

Does anyone happen to know why, if for example, the front sensors would not trip while in 2wd but WILL trip while in 4wd? I would assume the vehicle is taking data from all 4 sensors regardless of the mode.

It does take data from all 4 at the same time. What I'm thinking is there might be a problem with the front 2 sensors (best to check all though, it's easy) when power is being applied to all 4 wheels.

 

[Fern]

I get that when I accelerate from a dead stop while on a steep incline. Maybe with the longer springs the vehicle rocks back more now on acceleration and causes that to occur.

 

[AZPartsGuy]

I started reading this post and hoping there would be a definitive answer before I realized I am OP!! Ha.

To this day all of the original problems exist and I have done 0 things to remedy it. Camelback wants $200 a piece for the sensors, and the aftermarket offerings don't have many reviews.

I looked through the service manual and I found on page 422 that Toyota provides the resistance values for the sensors, so I may muster some motivation to check these out soon.


https://imgur.com/8JJVHG6

 

[4-Ripcord]

i've had this issue before as OP describes, trac wants to kick in and cut power for no reason when taking off from a stop in any mode except 2wd. Not even having trac/vsc disabled with the Anymod would stop this behavior.


From this yotatech post on zero point calibration: https://www.yotatech.com/forums/f2/01-02-4runner-how-zero-point-calibrate-your-vsc-system-203498/

I did many times to no avail. HOWEVER, when I did the "system test" as it describes towards the end of the post these symptoms stopped.

Also you can do a test of the VSC system put shorting the above pins and turning on the ignition. The VSC TRAC light will come on then start to flash rapidly at .013 sec intervals. This flashing means the VSC system is working properly and has no error codes stored.

give that a shot, OP

 

[sugjavier]

i've had this issue before as OP describes, trac wants to kick in and cut power for no reason when taking off from a stop in any mode except 2wd. Not even having trac/vsc disabled with the Anymod would stop this behavior.


From this yotatech post on zero point calibration: 01-02 4Runner How to Zero Point Calibrate your VSC system. - YotaTech Forums

I did many times to no avail. HOWEVER, when I did the "system test" as it describes towards the end of the post these symptoms stopped.



give that a shot, OP

Anyone else confirm the above works?
I will try it soon after I go in the shop to get my new front shocks/coils installed but I am so done with this issue.

I rather stay on 2wd in the winter
VS
doing the AWD (4 green lights) or 4WD (4 green lights with a center orange light)

I'm trying to pull out of a parking lot making a left or right turn and it decides it will cut power so my front end is halfway out and I'm sitting there with the deer in the headlights look trying not to die....happens a lot too even if just going straight from the stop light and accelerating slowly or fast...

I get the same exact symptoms, slip indicator, springy noise which sounds like ABS, no power for like 3-5 secs...enough for someone to t bone me or someone to honk at me from behind if I'm taking too long trying to turn or go forward.

 

[copev2]

Did you ever get this figured out OP? My 4Runner is doing the same thing after replacing my axles with extended travel axles. No ABS or CEL, just the slip light and limp mode