FogRunner

After putting on a lift (body or springs) allot of 4Runner owners notice the VSC will cut power when not needed causing saftey issues or just pure annoyance. The solution to this is to recalibrate the yaw rate sensor on the VSC system.

Recalibration is simple to perform and all you need is a level surface and a 4 inch long wire stripped at both ends.

To reset the VSC have the vehicle parked on a level surface both front and back and side to side (this is very important).

After that roll the window and turn on the ignition but don't start the engine. With the ignition on open the diagnostic port on the driver side of the engine.



Now take the piece of wire and short the two pins ( E1 and TS) 4 time or more with in a 8 second period. After doing this quickly look in the window to see if the VSC light came on again, it should be on for several seconds and then go out. (Note don't have someone sitting in the vehicle looking for the light it will make the vehicle unlevel ).

After this REACH IN THE WINDOW and turn off the ignition. Then wait a few seconds and REACH IN THE WINDOW again and turn on the ignition and wait for the VSC TRAC light to go out.

After this the VSC yaw sensor has been recalibrated and the issues of the VSC system de-throttling when un necessary should be eliminated.

NOTE even if you don't have a lift on your 4runner this should be done time to time to compensate for spring sag which also brings the VSC system out of calibration.

Also you can do a test of the VSC system put shorting the above pins and turning on the ignition. The VSC TRAC light will come on then start to flash rapidly at .013 sec intervals. This flashing means the VSC system is working properly and has no error codes stored.


Also I made a PDF of this post for easy print or archival for later use (keep a copy in the glove box) http://www.fogwireless.com/HAM/vsc.pdf



FOG

Deceptiwave

This is the first time I have ever heard of this. Is this a common issue when lifting a 4runner?

FogRunner

Yea its a common problem on 4Runners 01-02 (which are the ones with VSC system).

Most people don't realize its a problem because they are already used to the VSC being an annoyance. So after they put on a lift it becomes more common especially in 4WD but most don't ever realize the connection of the lift and the VSC system being more overly sensitive.

The VSC system uses two sensors a steering angle sensor hooked to the steering wheel and a yaw rate sensor. The yaw rate sensor needs to know what the normal angle of the car is side to side, front to back and front left to right rear and left rear to front right. It needs to know this to know when the vehicle is yawing IE skidding.

Because of this if you change the angles of the vehicles suspension it makes the yaw sensor out of calibration so it constantly thinks the vehicle is close to skidding or is skidding. So when it sees you turn the steering wheel and start to accelerate it thinks your in a full skid and goes nuts even though there is no skid at all.

Also aside from suspension or body lifts, just normal sagging of the rear springs will throw the yaw sensor out of calibration.

So it isn't really a problem per se its more like having to recalibrate your speedo when putting on bigger tires.



FOG

okie81

I've noticed it (or at least I think I have) kicks in more often, particularly on ice.

This is good stuff though, I didn't know there was a way to reset the Yaw Rate Sensor (that's ultimately what you're doing right?).

Thanks for the info

02_Limited

Cool, thanks for posting this. I had this done at the dealership before my lift when the VSC was just plain acting up, now it couldn't hurt to do it after the lift I'm sure.

FogRunner

Yes that is exactly what the above procedure is. When you do the procedure its telling the yaw sensor to erase what it thought was the center of the vertical axis (which is currently skewd because of lift or suspension sag).

Then when we turn the ignition back on the VSC system looks at the current vehicle position and sets that as the new vertical axis center.



FOG

eric-the-red

Great info FOG, it's now first on my list of things to do tomorrow.

Btw how level is your vehicle with the 883s in front. Mine was fine until I added the TJM and winch, now the front is down a bit.

FogRunner

Eric mine is pretty level with the ARB and the 9.5XP winch which is really heavy way over kill winch. My only excuse for the winch was it was on sale hehe.

But as far as the front being lower, higher or level it's no big deal once you zero calibrate the yaw sensor. As far as its concerned your driving a stock 4runner after calibration.

I was amazed at how much more mild manor the VSC system became after recalibration. Before I couldn't turn a corner at over 10-15 without it going nuts. Now I can drive like Evil Knievel and it doesn't act up unless I am truly skidding.

BTW you get on HF much or just stay above 30mhz ?



FOG

eric-the-red

I wasn't so much concerned about the calibration with the lower front, I am trying to decide whether to swap to 882 or 883 coils to level mine. Looks like the 883s will work.

I'm licensed for all frequencies but at the moment the only radio I have is the VHF/UHF in the truck. I've been looking at getting into HF but haven't done anything yet. The good news is there are no restrictions on antennas in my area. A guy just up the road has 2 50-60 foot towers with a few beams on each. Just have to talk my wife into letting me spend money on another hobby.

I did the calibration today using your instructions and ran into a problem. After resetting the yaw sensor I did a test drive and the VSC TRAC and VSC OFF lights came on as soon as I started moving. I read through the procedure in the FSM and noticed that it says to calibrate the deceleration sensor after calibrating the yaw sensor, before driving the vehicle. So to add to your instructions the procedure for the deceleration sensor is

1. Connect terminals T1 and ES again
2. Turn the ignition on
3. Check that the VSC TRAC light is on for about 4 secs and then starts blinking at 0.13 sec intervals
4. After the light has been blinking for 2 secs turn the ignition off
5. Remove the jumper wire

After doing this second procedure the lights are now off and everything works fine.

LINY4Runner

great info! I'm gonna get right on this!

AlexJet

and 03+ as well...

theferg

Sweet! I had no idea this could be done... Thanks for posting up the info. I'll be doing mine this weekend.

-Ferg-

Citykid

Very cool. Now this is for how the engine cuts power whenever you start to spin the tires also, right? I remember guys trying to get rid of this a while ago but it was also canceling out the ABS.
No problems there with this (ABS)?

glenyoshida

What fantastic information! Thanks so much for sharing this. I'm one of those that you mentioned that got so irritated I ended up putting on a bypass switch. I love that switch. It's prevented many a curse word. The PDF is really cool too. It's well written and organized. Top notch dude!

SWPERIC

OP. god bless you sir! My dealership told me there is not such thing as this. assuming i can get this to work, you (along with the rest of yotatech) will have kept me out of the dealership for 4 years! Thank you!

Rock Slide

iTrader: (1)

I'm looking forward to doing this recalibration this weekend. Dealership wanted me to pay $50 for this!

FogRunner

Thanks, I'm in the process of changing careers due to health reasons and my new career requires me to be very clear and concise with writing and instructing. I'm in the process of taking a technical writing class so your opinion is positive encouragement Switching careers in your 30's sucks.



FOG

SWPERIC

this still has not fixed what i was hoping it would. this is a bit of a thread jack but if anyone with experience in this area could take a look at my thread, it would be much appreciated.

okie81

We did this procedure on my brothers Taco this afternoon, then the VSC TRAC/VSC OFF lights came on as soon as we stated it up (as Eric mentioned above):

We did what he said to calibrate the deceleration sensor and it's fine now. Note: not only will the VSC TRAC light blink, the ABS light should blink as well (but not at such a high interval)

Very detailed instructions though Fog, thanks again.

rams

Where can i find a very good level surface??