Thanks to the various threads found on IH8MUD, I gathered enough knowledge on how to correct the steering wheel angle offset on my 2003 LX470.
Since I purchased the vehicle new in March of 2003, the steering wheel on my LX470 has always been off-center (to the left) by about 20 degrees. I have moved around the country in the past 18 years, and every time I took it to a Lexus dealer for service, I requested that they fix it to center: I was usually told it would entail pulling the steering wheel, which would require replacing the airbag. It turns out that there is not a technical reason to either pull the steering wheel or replace the airbag. I'm not saying there wasn't a legal or policy reason for needing to change the airbag, but that was what I was told by Lexus service over the past 18 years.
There are threads on this forum that mention this can be corrected by pulling the steering wheel, rotating it one or two splines (or more if you want), and reassembling. As claimed, this is very easy to do, if you have the right tools, including a steering wheel puller. Some people suggest using a rubber mallet to tap it off, but I discovered I needed the puller. Disassemble, pull, rotate, reassemble, took 15 minutes. This, though, did not really solve my problem. First, due to the electrical and mechanical design of the LX470 steering system, the spline rotation angles may or may not be aligned to "straight". I know nothing about Land Cruisers, but they may have a similar design to the Lexus LX470. In any case, for me, pulling the steering wheel and rotating only somewhat resolved the problem.
The real solution to this problem came through following the advice of getting a copy of TechStream and the OBDII/USB cable. I found v14 on Amazon with a cable. I won't post which one I bought, as I don't think that what I bought was the "best" or a particularly good deal. Installation instructions were unnecessarily difficult, and while it is operable, it seems that I can "break" the installation by clicking the wrong "upgrade" button.
I saw some OBDII connector hacks online using paper clips and shorting various pins together. Given the ease that TechStream solved my issues, I think it was the far better way to go.
On the LX470 (and probably Land Cruiser), there are at least two ECU's involved in steering straight at all speeds. The VSC TRAC ECU apparently uses a yaw sensor to determine if the vehicle is slipping sideways and gives feedback to the ABS controller to correct slip/skid. In hindsight, I realize that, for my LX470, the amount of "pull" on the steering wheel when driving straight, has always increased at higher speeds. The second ECU control involved is the VGRS system, an extremely important control, as it locks the rotation of the steering wheel to the mechanical steering control.
I won't go into the operational details of TechStream, as I just sort of "felt" my through it following some very poorly presented YouTube videos. If I can do it, anybody can.
There were four steps to getting my problem solved, although I took several attempts to get everything right, I am assuming that TechStream is installed on the PC and running and that the OBDII/USB cable is properly connected, and the vehicle selection is complete.
1. Find a location where you can get the vehicle tracking straight at 10-15mph and be able to stop where the vehicle is level. Get it tracking straight (my steering wheel was not "straight" but the tracking was). I just used a local parking lot that was level and had enough distance to get straight.
2. In the ABS/VSC ECU section of TechStream, clear the VSC yaw information from memory. Follow the instructions in TechStream.
3. After the memory is cleared, you need to calibrate the VSC yaw sensor. Strangely, this is in the "Test Mode" section. Again, just follow the instructions.
I want to emphasize here, this is setting the yaw sensor to know when the vehicle is tracking straight. A driveway is not long enough to verify you are tracking straight. You need some speed and distance to verify you are straight. A small error in the calibration will result in a large "pull" at freeway speeds.
4. Calibrate the steering wheel center position in the VGRS ECU sub-system. During this calibration, the VGRS actuator "frees up" the steering wheel, allowing it to turn freely without actually turning the wheels. This is why pulling the steering wheel is unnecessary to correct this problem, it is also why the steering column splines are not mechanically "locked" to the direction of the wheels.
Blowing off steam: a good Lexus/Toyota tech could have solved this problem years ago. I think I was pretty unlucky to have never encountered a knowledgeable tech in 18 years.
Upside: There are a couple of features in the LX470 control modules that are only accessible via TechStream, how the door locks and windows respond, lighting, remotes, etc. Not big game-changers, but conveniences.
Summary: fix your steering wheel offset using TechStream. First set yaw tracking, then set the steering wheel center. Although easy and fast, pulling the steering wheel doesn't fix the tracking issue. The tracking yaw calibration and steering wheel center should be adjusted in sequence. Total time to do this, once all the tools were in place: 10 minutes.
Since I purchased the vehicle new in March of 2003, the steering wheel on my LX470 has always been off-center (to the left) by about 20 degrees. I have moved around the country in the past 18 years, and every time I took it to a Lexus dealer for service, I requested that they fix it to center: I was usually told it would entail pulling the steering wheel, which would require replacing the airbag. It turns out that there is not a technical reason to either pull the steering wheel or replace the airbag. I'm not saying there wasn't a legal or policy reason for needing to change the airbag, but that was what I was told by Lexus service over the past 18 years.
There are threads on this forum that mention this can be corrected by pulling the steering wheel, rotating it one or two splines (or more if you want), and reassembling. As claimed, this is very easy to do, if you have the right tools, including a steering wheel puller. Some people suggest using a rubber mallet to tap it off, but I discovered I needed the puller. Disassemble, pull, rotate, reassemble, took 15 minutes. This, though, did not really solve my problem. First, due to the electrical and mechanical design of the LX470 steering system, the spline rotation angles may or may not be aligned to "straight". I know nothing about Land Cruisers, but they may have a similar design to the Lexus LX470. In any case, for me, pulling the steering wheel and rotating only somewhat resolved the problem.
The real solution to this problem came through following the advice of getting a copy of TechStream and the OBDII/USB cable. I found v14 on Amazon with a cable. I won't post which one I bought, as I don't think that what I bought was the "best" or a particularly good deal. Installation instructions were unnecessarily difficult, and while it is operable, it seems that I can "break" the installation by clicking the wrong "upgrade" button.
I saw some OBDII connector hacks online using paper clips and shorting various pins together. Given the ease that TechStream solved my issues, I think it was the far better way to go.
On the LX470 (and probably Land Cruiser), there are at least two ECU's involved in steering straight at all speeds. The VSC TRAC ECU apparently uses a yaw sensor to determine if the vehicle is slipping sideways and gives feedback to the ABS controller to correct slip/skid. In hindsight, I realize that, for my LX470, the amount of "pull" on the steering wheel when driving straight, has always increased at higher speeds. The second ECU control involved is the VGRS system, an extremely important control, as it locks the rotation of the steering wheel to the mechanical steering control.
I won't go into the operational details of TechStream, as I just sort of "felt" my through it following some very poorly presented YouTube videos. If I can do it, anybody can.
There were four steps to getting my problem solved, although I took several attempts to get everything right, I am assuming that TechStream is installed on the PC and running and that the OBDII/USB cable is properly connected, and the vehicle selection is complete.
1. Find a location where you can get the vehicle tracking straight at 10-15mph and be able to stop where the vehicle is level. Get it tracking straight (my steering wheel was not "straight" but the tracking was). I just used a local parking lot that was level and had enough distance to get straight.
2. In the ABS/VSC ECU section of TechStream, clear the VSC yaw information from memory. Follow the instructions in TechStream.
3. After the memory is cleared, you need to calibrate the VSC yaw sensor. Strangely, this is in the "Test Mode" section. Again, just follow the instructions.
I want to emphasize here, this is setting the yaw sensor to know when the vehicle is tracking straight. A driveway is not long enough to verify you are tracking straight. You need some speed and distance to verify you are straight. A small error in the calibration will result in a large "pull" at freeway speeds.
4. Calibrate the steering wheel center position in the VGRS ECU sub-system. During this calibration, the VGRS actuator "frees up" the steering wheel, allowing it to turn freely without actually turning the wheels. This is why pulling the steering wheel is unnecessary to correct this problem, it is also why the steering column splines are not mechanically "locked" to the direction of the wheels.
Blowing off steam: a good Lexus/Toyota tech could have solved this problem years ago. I think I was pretty unlucky to have never encountered a knowledgeable tech in 18 years.
Upside: There are a couple of features in the LX470 control modules that are only accessible via TechStream, how the door locks and windows respond, lighting, remotes, etc. Not big game-changers, but conveniences.
Summary: fix your steering wheel offset using TechStream. First set yaw tracking, then set the steering wheel center. Although easy and fast, pulling the steering wheel doesn't fix the tracking issue. The tracking yaw calibration and steering wheel center should be adjusted in sequence. Total time to do this, once all the tools were in place: 10 minutes.
