Strange Vehicle Stability Control Issue

[mdrohman]

SOLVED - Strange Vehicle Stability Control Issue

I was wondering if anyone has ever run into a similar issue before I or the dealership start throwing parts/money at the 4Runner.

2002 4x4 160k - has the multimode 4x4 and VSC

This winter, for the first time. The VSC will kick in and cut power when:
1) Starting from a stop and turning either left or right
2) On dry pavement
3) Only in all wheel drive mode

It doesn't kick in when in 2wd mode. It never did it last winter. I had the upper and lower ball joints replaced over the summer but I can't imagine that would effect it.

The problem really sucks. The AWD mode used to be awesome for MN winters when side roads wouldn't be clear but main roads are dry: just leave it in AWD. Now the 4Runner is way safer in 2wd because in AWD it's a crap shoot if the VCS is going to cut power and try to kill me every time I try to pull into traffic.

It's so strange to me that it seems to only malfunction in AWD mode and not 2wd.

I have double and triple check the tire pressures and re-calibrated the VSC system. The re-calibration actually helped a lot in 2wd - less interfering by the VSC - but didn't change anything in AWD.

Thanks for any insight
Matt

 

[mdrohman]

Fixed!!!

Update in case anyone else runs into a similar problem:

The fix was a new right front wheel sensor.

The old one had developed a hairline crack that was letting in moisture. The crack was underneath the o-ring for the sensor and wasn't noticed the first two times the sensor was inspected. The sensor also tested fine electronically in the shop but would act up on the road.

The front wheels sensors only check for wheel slip when in AWD mode which is why the car drove fine in 2wd.

We originally thought that the ABS tone ring had been messed up when the ball joints were replaced but that checked out fine. Second ideas was that the YAW sensor was not working but a replacement didn't change anything. Finally starting back at zero, a thorough inspection of the sensor revealed the crack.

Hope this helps someone,
Matt

 

[pb&j]

I have the same or similar problem. What was the part number and specifics? Any location help or photo for the part would be helpful. Thanks.

 

[mdrohman]

I had a shop do the work so I don't know many specifics. I do believe the front wheel sensor is the only set of wires going to front steering knuckle - basically seen in this post: http://www.toyota-4runner.org/3rd-g...front-wheel-speed-sensor-test-replacment.html. That post is about the "ABS sensor" in a 98 but it's the same thing (I'm pretty sure) as the "wheel speed sensor" on 2001 and 2002 4Runners.

 

[Xinirgi]

Thanks for the follow up. I've experienced this twice this winter so far, while never having it happen in the past. My fix has been the ABS/VSC/TRAC disable switch, never bothered with troubleshooting since it has only happened twice. I'll check the sensors first should it happen again.

 

[pb&j]

I had a shop do the work so I don't know many specifics. I do believe the front wheel sensor is the only set of wires going to front steering knuckle - basically seen in this post: http://www.toyota-4runner.org/3rd-g...front-wheel-speed-sensor-test-replacment.html. That post is about the "ABS sensor" in a 98 but it's the same thing (I'm pretty sure) as the "wheel speed sensor" on 2001 and 2002 4Runners.

Another question: Were there any indicators on the dash which indicated to you that it was the sensor? CEL or abs light etc...?

 

[mdrohman]

There were no dash indicators. Just the VSC light flashing when the system would activate (as described in the first post). The system thought it was operating properly. The sensor was just sending the wrong info.

 

[danielzak1990]

I was wondering if anyone has ever run into a similar issue before I or the dealership start throwing parts/money at the 4Runner.

2002 4x4 160k - has the multimode 4x4 and VSC

This winter, for the first time. The VSC will kick in and cut power when:
1) Starting from a stop and turning either left or right
2) On dry pavement
3) Only in all wheel drive mode

It doesn't kick in when in 2wd mode. It never did it last winter. I had the upper and lower ball joints replaced over the summer but I can't imagine that would effect it.

The problem really sucks. The AWD mode used to be awesome for MN winters when side roads wouldn't be clear but main roads are dry: just leave it in AWD. Now the 4Runner is way safer in 2wd because in AWD it's a crap shoot if the VCS is going to cut power and try to kill me every time I try to pull into traffic.

It's so strange to me that it seems to only malfunction in AWD mode and not 2wd.

I have double and triple check the tire pressures and re-calibrated the VSC system. The re-calibration actually helped a lot in 2wd - less interfering by the VSC - but didn't change anything in AWD.

Thanks for any insight
Matt

wow i am having a same issue, exactly how you explained it, everytime i accelerate from a stop in 4x4 the VSC cuts off the throttle and to stop it i have to let of the throttle and accelerate while the car is rolling, i will try re-calibrating the system first and if it doesnt work i will look at wheel sensors.