GX470 Slip Indicator and ABS - Right Turns (1 Viewer)

[tmwim2103]

I hope everyone is doing well and I'm hopeful that I can get some advice from those who know more than me.

I just purchased a 2004 GX470 and frankly, it's been thing after thing. I will spare the irrelevant details, but after seeing multiple mechanics over the last few weeks, it was uncovered that the steering rack and pinion, as well as the upper control arms needed replacement, which I just had done.

Additionally, the CV axles need to be replaced, but I have not done that yet.

The vehicle has a 3" lift and numerous after market modifications.

Prior to the repairs, the vehicle pulled aggressively and had quite a lot of play to both sides, especially at higher speeds. The handling felt like driving in high winds and was difficult to control. After advice from the shops, it felt like the control arms and rack and pinion would resolve. Although better, it's not great.

However, prior to these repairs, I did not experience what happened today. I picked up the car after the repairs and was driving about 50mph home through a mountain pass, and out of nowhere, the slip indicator light came on and the brakes locked while in a sharper right hand turn (dry pavement).

Freaked me out and almost ran me off the road because I wasn't ready for it. Took it slower the rest of the way home, until I got closer on some curvy roads, and the same thing happened two more times. Only on right hand turns at 30+ mph that are sharper.

Before the repairs, this did not happen.

I took it back to the mechanic the same afternoon, and they found a few codes ... ABS, Diff and a high or low battery code (I don't know the exact ones but can find out tomorrow).

They couldn't replicate the result during their test drive, cleaned the battery terminal and said let them know if it keeps happening.

They claimed to check the wheel sensors and all checked out, but when I drove home, same thing happened again ... Right hand turn, 30+ mph, slip indicator and brakes on the right side.

Just feels off like something wasn't done correctly during the rack and pinion ... Wanting some advice on what to do ... Shop wasn't aware of ZPC requirement with alignment and suspension/steering work so maybe that's a stating place ... Thanks in advance and happy to answer questions!

 

[Rednexus]

Mine would do that as well. It probably just needs a ZPC. You can easily DIY one in about 10 minutes. The rig just needs to be on totally flat ground with the wheels facing forward.

 

[tmwim2103]

Mine would do that as well. It probably just needs a ZPC. You can easily DIY one in about 10 minutes. The rig just needs to be on totally flat ground with the wheels facing forward.

That was done by a shop yesterday and it still didn't work unfortunately. I guess I can try it again?

 

[Rednexus]

That was done by a shop yesterday and it still didn't work unfortunately. I guess I can try it again?

I'd try DIY'ing it if you have a totally flat parking space (it does not take long so you can drive it somewhere flat and also run one). If the shop was not aware of the ZPC it's possible they screwed it up. If it still acts up after a proper ZPC, you probably have a sensor issue somewhere (steering angle sensor, wheel speed sensor, etc). You can pick up a code reader at Harbor Freight for ~$100-150 that will read those codes (per my daily HF spam emails, they are on sale this weekend ).

I DIY all of my own repairs but advise friends and family on their vehicles when they are getting serviced. I've found that the vast majority of mechanics at general shops (i.e., non-dealer, non-specialist in Toyota 4x4s) do not have the skills, time, or interest in properly diagnosing vehicles. After all, your mechanic probably had several other cars he needed to fix that day - so his incentive is to get you out the door so he can move onto the next one. You should be able to troubleshoot (or at least narrow down) this yourself with a new ZPC and a code reader.

 

[Beej]

For reference, on a Lexus GX470 (and Toyota trucks/SUVs in general), ZPC stands for Zero Point Calibration.

In the context of an alignment, it refers to calibrating the yaw rate and acceleration sensor (part of the vehicle’s stability control / VSC system).

Here’s why it matters:
• After doing an alignment, suspension work, or anything that changes ride height, the vehicle’s stability control system may think the car is drifting or leaning when it’s actually going straight.

• The ZPC resets the “zero” reference so the VSC/ABS/traction control know what true level and straight-ahead is.

• If you don’t perform ZPC after alignment (or after disconnecting the battery, replacing steering/suspension components, etc.), you might get VSC or ABS lights, or the stability control might intervene unnecessarily.

It’s usually done with a scan tool (like Techstream) or by a pedal/OBD jumper sequence.

(This explanation might not be exactly right)

 

[tmwim2103]

I'd try DIY'ing it if you have a totally flat parking space (it does not take long so you can drive it somewhere flat and also run one). If the shop was not aware of the ZPC it's possible they screwed it up. If it still acts up after a proper ZPC, you probably have a sensor issue somewhere (steering angle sensor, wheel speed sensor, etc). You can pick up a code reader at Harbor Freight for ~$100-150 that will read those codes (per my daily HF spam emails, they are on sale this weekend ).

I DIY all of my own repairs but advise friends and family on their vehicles when they are getting serviced. I've found that the vast majority of mechanics at general shops (i.e., non-dealer, non-specialist in Toyota 4x4s) do not have the skills, time, or interest in properly diagnosing vehicles. After all, your mechanic probably had several other cars he needed to fix that day - so his incentive is to get you out the door so he can move onto the next one. You should be able to troubleshoot (or at least narrow down) this yourself with a new ZPC and a code reader.

How do you guarantee perfect center of you don't have a tool/computer/techstream?

Finding a completely flat surface that has 8-10 seconds of drive time at 25-30mph is quite difficult in the Rocky Mountains, so any advice would be great here.

 

[Rednexus]

How do you guarantee perfect center of you don't have a tool/computer/techstream?

Finding a completely flat surface that has 8-10 seconds of drive time at 25-30mph is quite difficult in the Rocky Mountains, so any advice would be great here.

My roads here in the Ozarks are twistier, steeper, and narrower than most of your roads in the Rockies .

TBH I've never bothered with the second half of the ZPC procedure. I do the ZPC in my garage and then drive the rig. It had the same problem your had for months until I got around to the ZPC. There was one backroad corner on particular on the way to one of my favorite hiking areas that VSC would always get triggered on (right turn as well). The computer-less ZPC w/o the recommended flat driving totally fixed it.

 

[tmwim2103]

My roads here in the Ozarks are twistier, steeper, and narrower than most of your roads in the Rockies .

TBH I've never bothered with the second half of the ZPC procedure. I do the ZPC in my garage and then drive the rig. It had the same problem your had for months until I got around to the ZPC. There was one backroad corner on particular on the way to one of my favorite hiking areas that VSC would always get triggered on (right turn as well). The computer-less ZPC w/o the recommended flat driving totally fixed it.

Much appreciated ... Here's another variable to just make things even more complicated ... CV boot/axle on the right side was noted to need a change due to some tears in the boot itself. At the time of inspection, there was no noticeable grease, but checked it this morning before driving, and grease is only on the right side at this point.

Feels like this could also be a culprit in throwing some faulty reads in VSC, but not sure if that's been anyone else's experience too.

 

[Rednexus]

Much appreciated ... Here's another variable to just make things even more complicated ... CV boot/axle on the right side was noted to need a change due to some tears in the boot itself. At the time of inspection, there was no noticeable grease, but checked it this morning before driving, and grease is only on the right side at this point.

Feels like this could also be a culprit in throwing some faulty reads in VSC, but not sure if that's been anyone else's experience too.

A torn CV boot should not affect the VSC. The speed sensor is inside the front steering knuckle and is well-sealed (i.e., grease getting thrown on it won't affect it). If there were a wheel speed sensor issue, it would throw a code right away and your VSC/TRAC/ABS lights would be constantly illuminated, as the computers in the rig can't run those systems without speed sensor data from all 4 wheels.

I'm 90% sure a parking lot ZPC will fix your issue. It's really quite sensitive if things are just a little bit off.