I installed an aftermarket steering wheel a few weeks ago and got the VSA and (!) lights on with no ABS or Airbag lights. I checked with HDS and it reported lots of VSA codes including one for 27-1. I reset them, but 27-1 would instantly return. And because the DTC would instantly set, the software wouldn't even let me enter any 'Function Tests' or let me do the 'VSA Neutral Position' adjustment.

I thought my SAS was defective for sure. But when I went into the datalogging screen, it was able to read a value in degrees for the SAS and it seemed to correlate to how much I moved the wheel. It read +174 degrees with the wheel centered but I played around with the notched ring trying to see how far I could turn it in either direction and there seemed to be no limit. I could turn it CCW as many times as I wanted and it would 'bottom out' at a reading or -714 degrees and 'top out' at 720 in the CW direction. I realized this was some sort of rotary encoder wheel setup and different in mechanism than the 'clock-spring' that lets the airbag, cruise, and horn wires rotate.

The values seemed to either change by 5 or 6 degrees. For example, it would go from 0 to 6 to 11 to 17 as you turned the wheel CW. I realized this meant the underlying step value was somewhere around 5.5 and rounding to an integer was causing a change in either 5 or 6. Then I added up the range of about -714 to 720 and divided by 256 which is the steps allowed by 1 byte of hexadecimal. Sure enough, right around 5.5. (720+720)/256 = 5.625


So, I believe the 2006+ S2000 SAS uses an optical encoder disc, an IR LED, and IR sensor to read angular position. It then passes this on to the VSA module via CAN using 1 byte that linearly correlates 0-255 to -720 to 720 degrees.

Anyway, so how did I fix it? Because it wouldn't let me force reset the learned neutral position, I simply turned the notched ring till it read 0. This lined up the notches in the 12 o'clock and 6 o'clock positions with the wheel centered. But if yours doesn't you may have to unplug the green SAS plug with the ignition on, turn the notched ring to what the datalogged values say, plug it in again, and then rotate back to 0. Or some combination of that. While playing with all of this I somehow managed to get the datalogger to read about 70 degrees with the notch straight up. I then unplugged the connector, rotated the ring to 70 degrees and plugged it back in and then rotated back to 0.

Even after all of this, clearing the DTC would still have it come back instantly. I couldn't figure out why because clearly the sensor was reading correctly. I buttoned it all up and looked up the cost of a new SAS from Honda, and went to freaking bed.

The next day, I left for work and drove with the wheels straight for less than 1/4 mile and both VSA and (!) lights went away!


Anyway, couldn't have done this without HDS. Worth the gamble buying a knock-off from China, lol. Also, please fully understand the difference between the 'clock-spring' and the 'notched ring' before you go around messing with this. The 'clock-spring' is limited to about 6 end to end rotations. I turned it all the way to one side and then turned it in 3 revs. The 'notched ring' you can turn forever in any direction with a little flat head screwdriver.


Hope this helps someone.

 

whats the HDS tool that you used? can you provide a link? thanks

 

Great info, you got me all the way to the very end where everything is lined up between the steering wheel being straight and the steering angle sensor reading 0 degrees. Unfortunately, even with everything seeming perfect, the VSA and traction control lights stay on.

Battery reset doesn't work. Drove around for 10 miles with the sensor reading 0 degrees didn't work. Clearing the 27-1 code in the Honda HDS HIM device didn't do anything, it just keeps coming back immediately as soon as the ignition is turned on.

If anyone has any clue about what else I can do, please let me know. The ONLY code I have after scanning every module within HDS on my whole car right now is the 27-1 "Steering angle sensor failure".

 

Where the heck is the SAS located?

 

Supposedly, it's located inside of the combination switch body (which you're supposed to replace as a unit according to Honda). That combination switch body houses both the left and right gear stalks... I'm not really sure outside of that without seeing it in person. Documentation is found in 19-124 of the service manual, with part number 35251S2AA51.
I do wonder if the original poster initiated a VSA adjustment after it was set to neutral correctly... but that wouldn't really change anything. At the same time, the Honda manual does recommend:

> Clear the DTC
> Slowly drive the vehicle straight for 10 feet, then park the vehicle
> Check if it's still 0
> Turn off the car
> Remove HDS

I hope it's the 1 in a million chance that it is really as simple as driving straight for 10 feet without turning the steering wheel that you might not be able to do if you're in... say, a parking garage or something like that.

 

I did mine a couple years ago, its behind the clock spring. Its black plastic with a green bearing that connects with the steering wheel. I got one pulled out of a wrecked car and after an alignment it was good to go, was thinking I'd need a Honda computer to get it reset, but a simple alignment after the SAS was swapped got me sorted.

 

Cool!

After some extensive suspension work which involved removing the steering coupler and subframes, my car started throwing a SAS code which disabled VSA.

I don't have a clockspring, so I wasn't being careful about the steering wheel free spinning.

I love that my VSA is permanently disabled. But part of me wants to fix the issue just because its an issue.

....
but I do enjoy not having to remember to turn off VSA when I get in the car....

 

Until you get stuck in a hwy downpour and wish you still had vsa

 

Nope. I've had a MY00 for 17yrs now, in plenty of downpours. My MY07 had working VSA when I first got it, and I found it infuriating.

Everyone's different. But...I turn off traction control regardless of weather conditions or vehicle.

Actually, the only time I leave it on is when I'm sure it won't kick on it. Like...a leisurely drive in my giant SUV on a dry sunny day.

I have many long, boring theories on why traction control is just one of the many tools of the devil.

 

Wanted to update folks because I figured this out. If you're completely lost in the mix of these issues, here's the complete fix. This only works with Honda HDS.

Just be warned that if you don't know what you're doing you could make things worse.

Do not perform these steps if your car does not have a good alignment.

Major Step 1

1. Point the front wheels perfectly straight forward, turn the car off, and disconnect battery.
2. Then remove the steering wheel + airbag+ clockspring.
3. Tape the clockspring so it doesn't move or rotate at all.
4. Set the airbag and clockspring off to the side until the very end.
5. Reconnect battery and turn the ignition all the way on but do not start the car.
6. Go to Major Step 2.

Major Step 2 (Checking steering rack centered position)

1. Once again, make sure the front wheels perfectly pointed straight forward.
2. Connect your car to your computer with the Honda HDS/HIM software.
3. Go into the ABS/TCS/VSA menu and open the sensors page to view the live data of the sensors.
4. Looking for "Steering Angle" and take note of the current value.
5. If the current value is anything other than 0 degrees:
   1. Turn the car off and remove the steering wheel.
   2. Rotate the blue notched ring at least five full rotations in any direction.
   3. Make sure that the rectangle notches on the blue notched ring are at 3 o'clock and 9 o'clock positions when you're done rotating. This is critical.
   4. Turn the key back on, and Honda HDS should reconnect quickly.
   5. Continue repeating the above substeps 1-4 until the steering angle sensor reads 0 degrees. This could take upwards of 10 times.
6. Continue to step 7 below this line when the steering angle sensor reads 0 degrees and the front wheels are perfectly pointed straight forward.
7. With the key turned on, rotate the steering wheel all the way to the left. Hold the steering wheel tightly as far left as it will go, and record the value you see in Honda HDS. It should be somewhere between -360 and -500.
8. Now the other way, rotate the steering wheel all the way to the right. Hold the steering wheel tightly as far right as it will go, and record the value you see in Honda HDS. It should be somewhere between 360 and 500.
9. Compare the two numbers. They should be the same numbers, but one is negative and the other is positive.
   1. Good example: if the left turn value is -420 and the right turn value is 420, then you're good!
      1. (More good examples are -400 and 400 or -386 and 386)
   2. Bad example: if the left turn value is -380 and the right turn value is 460, then you're NOT GOOD.
      1. (More bad examples are -390 and 410 or -415 and 430)
   3. The specific numbers themselves don't matter, as long as they are the left negative value is the same as the right positive value.
10. Go to Major Step 3 if the left negative value and right positive value ARE NOT matching each other. See bad examples above.
11. Go to Major Step 4 if the left negative value and right positive value ARE matching each other. See good examples above.

Major Step 3 (Centering the steering rack with your wheels and the steering angle sensor)

1. So your steering rack isn't centered with your wheels and the steering angle sensor. Time to fix it.
2. Time for some math, using your left turn value and right turn value from above, find the exact middle point value between both of them by adding the two numbers together.
   1. For example, if your left turn value is -380 and your right turn value is 460, then -380 + 460 = 80. Your middle point value is positive 80 degrees.
3. CUT your middle point value in half to get the final adjustment value.
   1. Using the example above, half of 80 = 40 degrees.
4. Turn the steering wheel so that the steering angle sensor in Honda HDS/HIM is showing your final adjustment value.
   1. Using the example above, Honda HDS/HIM should be showing 40 degrees.
5. Now perform the steering angle reset procedure by doing the following:
   1. Turn the car off and remove the steering wheel.
   2. Rotate the blue notched ring at least five full rotations in any direction.
   3. Make sure that the rectangle notches on the blue notched ring are at 3 o'clock and 9 o'clock positions when you're done rotating. This is critical.
   4. Turn the key back on, and Honda HDS should reconnect quickly.
   5. Continue repeating the above substeps 1-4 until the steering angle sensor reads 0 degrees. This could take upwards of 10 times.
6. When the steering angle reset is done, recheck your full left and full right steering angle positions.
   1. They should be the same numbers, but one is negative and the other is positive.
   2. Using the example above, we corrected -380 and 460 by adjusting it 40 degrees to the left, so now the full left value should be -420 and the full right value should be 420.
7. If this doesn't work the first time, you should be getting closer. Repeat the process until the full left negative value and full right positive value are a matching pair.
8. Put the steering wheel back on, and rotate until the steering angle value in Honda HDS/HIM is showing 0 degrees.
9. At this point your steering rack is fully centered to 0 degrees when your front wheels and steering angle sensor are perfectly centered and set to 0 degrees.
10. Remove steering wheel and look for the notch on the spline of your steering shaft.
    1. If the steering shaft notch IS NOT pointing perfectly straight up then go to Major Step 4.
    2. If the steering shaft notch IS pointing perfectly straight up then go to Major Step 5.

Major Step 4 (Centering the steering shaft and steering wheel with the steering rack)

1. The steering shaft notch IS NOT pointing perfectly straight up with the steering rack centered, and that needs to be fixed.
2. Make sure the wheels are still perfectly straight forward and the steering angle sensor still reads 0 degrees.
3. Jack the car up in the front, and unbolt the steering joint so that the steering shaft and steering rack are disconnected from each other.
4. Get back in the car and rotate the steering shaft with your fingers until the the steering shaft notch is pointing perfectly straight up.
   1. Do not let the steering angle sensor (blue notched ring) move out of the 0 degree position while doing this.
5. Slide the clockspring back onto the steering shaft and it should easily click and fit onto the steering angle sensor (blue notched ring) if it is still at 0 degrees.
6. With all pieces (notches/arrows/etc) pointing straight up, slide the steering wheel (perfectly straight up) onto the steering shaft, perfectly aligned with everything else.
   1. There are holes on the back of the steering wheel that fit directly onto the clockspring's aligning stubs.
7. Reconnect the steering joint/shaft/rack with the new spline position, and bolt it back together.
8. By this point, this is what you should end up with:
   1. The steering wheel is perfectly straight
   2. The steering shaft notch is perfectly facing up
   3. The clockspring should be perfectly straight and clicked onto the steering angle sensor
   4. The steering angle sensor is 0 degrees
   5. The steering rack is perfectly centered
   6. The front wheels are perfectly pointed straight forward
9. If all of the above 1-6 is true, proceed to Major Step 5.

Major Step 5 (Finalizing everything and clearing the errors)

1. EVERYTHING by this point is perfectly aligned, centered, etc.
2. Go into the ABS/TCS/VSA menu in Honda HDS/HIM, and clear the DTC's.
3. Go drive the car around for a few miles, and make sure that you try to keep the steering wheel as straight as possible during most of the drive.
4. Go back home and turn the car off for 15 minutes, and then turn it back around and drive again.
5. All ABS/TCS/VSA codes that were caused by this issue should be cleared in less than a mile!