Rear Axle Diff Lock Reduced

[TexasCF]

I recently installed an aftermarket steering wheel on my 22. After install, it wasn't perfectly centered with the dash, went to get it aligned. After alignment I had this message show up on the idrive and had Cont. Driving Possible: Chassis Stabilization show up on the dash. Went back to where I got it aligned, told them what was going on. They did whatever, figured the problem is due to a software upgrade. I knew that wasn't the issue, but whatever. Got that taken care of. Went to the local dealership today and told them the situation. Eight hours later and $600 poorer they couldn't fix it and blamed it on the aftermarket steering wheel, and also added the steering wheel light on the dash now as well. They initially stated that the place that did the alignment failed to do a Electronic Power Steering start up and yaw rate. The dealership stated they did this continuously and failed due to degree outside specification. They did an alignment and then did all of that and stated alignment is approved.

Doing this still didn't get rid of those messages above. They stated they did all of that, connected tech stream and got into the INSTA software to perfrom the EPS start up which failed twice. They state they believe the steering wheel was installed not centered to the steering gear, preventing from having the EPS start up completed. Stated they need an OEM wheel installed properly to see if this is the issue. After they told me it would be all together $2400 including the OEM wheel I told them no.

I was under the impression, the steering wheel can only go on one way, is it possible I screwed this up when I installed my wheel? None of these issues were present after I installed, only after the initial alignment. The person I was working with at the counter hinted that they do the turn the wheel from one side and then to another, but there is a post under here that states that doesn't work with the Supras. Any guidance and/or direction will be greatly appreciated.

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[MyronGains]

I’ve been troubleshooting a reduced diff lock error since April of this year. I went back to factory size tires, took it to two different dealerships, one of them actually replaced the whole rear diff.

It still came back.

It can happen because your tire pressures are uneven, it can happen because your diff is shot. If you don’t have a specialty shop near you, your best bet is to return it to stock and try another dealer.

 

[TexasCF]

I’ve been troubleshooting a reduced diff lock error since April of this year. I went back to factory size tires, took it to two different dealerships, one of them actually replaced the whole rear diff.

It still came back.

It can happen because your tire pressures are uneven, it can happen because your diff is shot. If you don’t have a specialty shop near you, your best bet is to return it to stock and try another dealer.

The only thing that is not stock is the steering wheel and a CAI.

 

[MyronGains]

The only thing that is not stock is the steering wheel and a CAI.

The dealer will make endless excuses not to actually troubleshoot anything until the steering wheel is off and back to stock. Trust me. They may even somehow try to point to the CAI.

 

[TexasCF]

They were wanting $1800 for an OEM wheel install. I told them I was done when that was brought up.

 

[itzTang]

simple fix. reinstall oem steering wheel. make sure all connections are tight and not pinched by anything.

 

[razorlab]

Tie rods are probably different lengths enough to cause an error, since you got it aligned with a wheel not installed correctly, the tie rods now make up the difference. Make sure you center the wheel on the steering shaft.

 

[Eastwood]

Use ISTA to calibrate your SAS.

Had a similar issue after my coilovers were installed. Prior to that I had an aftermarket steering wheel installed that was slightly off, got it aligned no issues. Then got coilovers later and that warning plus several others popped up. No one could solve it, so I downloaded Techstream and ISTA and reset the SAS and it solved everything. No issues since then, even when I switched to a JQ Werks wheel.

 

[exe36m3]

Consider going to a BMW independent shop.
They WILL know more about your Toyota Supra than Toyota will.

2 aftermarket steering wheels on/off, 3 alignments, and still no lights or issues.

 

[jmikes]

These errors all stem from the steering angle sensors being in conflict or not reading properly. Same thing that happens if your steering wheel is way off-center after an alignment.

Double check your install to ensure everything is on straight. May have to get it recalibrated at Toyota or another shop that deals with a lot of BMW's if you can't find anything off-center.

 

[jaimeslo]

I recently installed an aftermarket steering wheel on my 22. After install, it wasn't perfectly centered with the dash, went to get it aligned.

a good reputable aftermarket steering wheel should go on straight. unless someone hamfisted the wheel on without paying attention to the indentation which is almost impossible...

and I hope you didnt get the one from aliexpress/temu...

did you check the indent before installing to make sure it aligns perfectly? if your wheel is not straight as per OEM spec then the alignment will totally screw everything up.

 

[lucky phil]

a good reputable aftermarket steering wheel should go on straight. unless someone hamfisted the wheel on without paying attention to the indentation which is almost impossible...

and I hope you didnt get the one from aliexpress/temu...

did you check the indent before installing to make sure it aligns perfectly? if your wheel is not straight as per OEM spec then the alignment will totally screw everything up.

The wheel can only be installed one way, however the splines are so fine that even if they have been broached a degree out of clock it will make a noticeable difference at the wheel rim. Even a replacement OEM wheel may not be as perfectly aligned as the original that's why it's centred during a wheel alignment and the steering angle sensor is able to be calibrated to the null position if required because there are production tolerances involved. Just like everything OEM or aftermarket.
Phil

 

[razorlab]

The wheel can only be installed one way, however the splines are so fine that even if they have been broached a degree out of clock it will make a noticeable difference at the wheel rim. Even a replacement OEM wheel may not be as perfectly aligned as the original that's why it's centred during a wheel alignment and the steering angle sensor is able to be calibrated to the null position if required because there are production tolerances involved. Just like everything OEM or aftermarket.
Phil

"It can only be installed one way" then proceeds to contradict that because of the fine splines and it could be installed about 50 different ways if you ignore the center mark. Sometimes I wonder if people proof think their thoughts before typing.

 

[lucky phil]

"It can only be installed one way" then proceeds to contradict that because of the fine splines and it could be installed about 50 different ways if you ignore the center mark. Sometimes I wonder if people proof think their thoughts before typing.

The wheel has a "master spline" so it can only be installed on the shaft in 1 position. If the wheel splines have been broached incorrectly on the new or replacement wheel with relation to the wheel rim and spokes is what I mean. So although you install the wheel with the master spline correctly to the steering shaft(the only way in reality) but the wheel centre splines have been broached incorrectly on the replacement then when you fit the replacement wheel it wont be centred like the original wheel. whats wrong with this statement?
Phil

 

[MyronGains]

Posting my experience in getting this resolved in case it happens to someone else and they’re googling it.

After 11 months of troubleshooting, giving up and buying a Corvette but being too stubborn to sell the car…

In my case, the Rear Axle Diff Lock Reduced Error was NOT caused by…

1) Bad Front Brakes (Thanks Toyota Dealer #2 for the stellar recommendation Replaced pads & rebuilt cooked caliper at indie shop)

2) Rear Diff (Replace Under Warranty by Dealer #1)

3) Trans Pan (Replaced under warranty)

4) Tires wider than OEM (went back to stock spec PS4S from Hankook RS4. Didn’t fix. )

5) Rims smaller than OEM (Was running 18s, went back to 19. Didn’t fix.)

What the issue was…drum roll please.

Bad ABS module. Although it calibrated and tested OK through ISTA in the present, it had thrown a code at some point in its life.

Hope this helps other people resolve their issues faster.

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