Problem with torque sensor?

[Willie Swoopes]

Originally Posted by Willie Swoopes

Doesn't torque steer usually apply to front wheel drive because the drive shafts are unequal in length due to the transmission sitting off to one side of the engine compartment? Since they are different lengths they twist at different rates and one wheel gets a bit more torque than the other. I believe the engineers compensate for this by making the unequal length shafts also unequal thicknesses so it compensates for the metal when it binds under heavy acceleration.

But what do I know, I fix computers for a living.

[guybo]

Originally Posted by Tcoat

Yes he should have bought matching tires and still should even with them on the front. It doesn't sound like it was on there long enough to have damaged anything though.

2 months, over 200 miles.... I hope not but that's more than enough at highway speeds.

86's have no torque steer at all. There isn't enough torque even if it was FWD. The mechanic may not know this car and may assume that it is FWD (I get that sometimes- people are surprised it's RWD) or is intimidated by a car he knows nothing about but since it's a flat 4 he assumes it's wierd or whatever.

Bottom line- don't go to this hack again with this car.

[ermax]

Originally Posted by covance

Hello all!



2015 BRZ with 25,000 miles on it. I had my rear driver side tire blow out recently and had to get a new quickly, so it unfortunately it does not match the passenger rear tire from a thread pattern and brand perspective. However, size and approximate wear do match (not many miles on the car).



I took my car in to get an alignment. The alignment was done properly, but the mechanic said he believes there is a problem with my torque sensor. When you step on the gas (for example at highway speeds) there is a significant pull to the left, and when you let off the gas the car goes back to the right. This phenomena does not happen at lower speeds on city streets. The mechanic said this excessive steering torque should be automatically corrected by the electric steering but it is not.



There are no error lights on the dashboard.



I am thinking of switching the front and rear driver side tires to see if the problem goes away (so that the two rear tires will be matched).



I told my mechanic this and he said he already tried this and it did not work. He thinks it is definitely a torque sensor/software issue and that I need to take it to Subaru before my warranty is up (that is a whole other issue. I have not hit 36k miles but have passed 3 years. I called one dealer who said ECU is not covered by the 5 year powertrain warranty but based on some Googling I think he was BSing me).



Any thoughts on this issue? Am I going about this the right way?



Thanks everyone for your thoughts. I wasn't sure what "technical issue" subforum this belongs in so I am posting in the general section for now.

This guy has absolutely no clue what he is talking about. If you have two different tires on the drive wheels you will obviously have pull. If the larger tire is on the rear right then the car will pull to the left on throttle and pull to the right off throttle. It’s very basic physics. Funny he thinks the electronic PS should compensate for this. Hahaha

[ermax]

The torque sensor on this car is to detect the load we are putting on the steering wheel so it knows how much PS assist to give. There is a calibration process you can do in Techstream. But even if this sensor was off it wouldn’t cause the car to turn one way or another. It would just make the wheel overly heavy or overly light.

[ermax]

Originally Posted by Willie Swoopes

Doesn't torque steer usually apply to front wheel drive because the drive shafts are unequal in length due to the transmission sitting off to one side of the engine compartment? Since they are different lengths they twist at different rates and one wheel gets a bit more torque than the other. I believe the engineers compensate for this by making the unequal length shafts also unequal thicknesses so it compensates for the metal when it binds under heavy acceleration.

Or have a half shaft the runs from the diff to the other side and mounted to the back of the block then from there it has an equal length axel to the wheel.

[cjd]

Originally Posted by guybo

There isn't enough torque even if it was FWD.

It only requires a difference between drive wheels. It doesn't need a lot of torque. In this case, there was a difference due to tires. FWD nearly always have it because of different axle lengths.

Its a different beast with a high torque engine, but that doesn't mean its not a thing without.

[ermax]

Originally Posted by cjd

It only requires a difference between drive wheels. It doesn't need a lot of torque. In this case, there was a difference due to tires. FWD nearly always have it because of different axle lengths.



Its a different beast with a high torque engine, but that doesn't mean its not a thing without.

Agree. I had torque steer on my old Integra which had equal length axels and less torque than the FRS. I will never go back to FWD if I can help it.