Yaw Rate and Acceleration Sensor Zero Point Calibration

[iDRiVaT4R]

EDIT: Here are the steps for performing Zero Point Calibration taken from the 5th Gen 4Runner Repair Manual.

IF your 4Runner is equipped with either DAC or Crawl Control, you must complete steps 4 and/or 5 or you will get a DTC and the slip indicator will always be lit.

I highly recommend this calibration if you think the VSC on your 4Runner kicks in too much, before or after lift. Mine was overreacting both before and after the lift, now for daily driving don't even know its there.

PERFORM YAW RATE AND ACCELERATION SENSOR AND STEERING ANGLE SENSOR ZERO POINT CALIBRATION [Using SST Check Wire (basically an electrical wire with each end stripped, also If possible solder each end. Just makes using the cable a bit easier.)]

NOTICE:

* While obtaining the zero points, keep the vehicle stationary and do not vibrate, tilt, move, or shake it (do not start the engine).
* Be sure to perform this procedure on a level surface (with an inclination of less than 1%).

(a) Clear the zero point calibration data.

(1) Turn the ignition switch off.

(2) Check that the steering wheel is centered.

(3) Check that the shift lever is in P.

(4) Turn the ignition switch to ON.

(5) The ABS warning light and slip indicator light come on for 3 seconds to indicate that the initial check is completed.

(6) Using SST, connect and disconnect terminals 12 (TS) and 4 (CG) of the DLC3 4 times or more within 8 seconds.

Front view of DLC3

(7) Check that the slip indicator light comes on.

(b) Perform zero point calibration of the yaw rate and acceleration sensor.

(1) Turn the ignition switch off.

(2) Check that the steering wheel is centered.

(3) Check that the shift lever is in P.

NOTICE:

* DTCs 36 (Zero Point Calibration of Yaw Rate Sensor Undone) and 39 (Zero Point Calibration of Acceleration Sensor Undone) are stored if the shift lever is not in P.
* If a DTC is output that indicates zero point calibration is incomplete, repeat the procedure starting at the step for clearing the zero point calibration data and system information.

(4) Using SST, connect terminals 12 (TS) and 4 (CG) of the DLC3.

Front view of DLC3

(5) Turn the ignition switch to ON.

(6) Keep the vehicle stationary on a level surface for 5 seconds or more.

(7) Check that the slip indicator light comes on for several seconds and then blink in the test mode pattern (0.125 seconds on and 0.125 seconds off).

HINT:

* If the slip indicator light does not blink, perform zero point calibration again.
* The zero point calibration is performed only once after the system enters test mode.
* Calibration cannot be performed again until the stored data is cleared.

(8) Turn the ignition switch off and disconnect SST from the DLC3.

(c) Drive the vehicle straight ahead at 40 km/h (25 mph) or more for at least 10 seconds. (I was unable to do this task, just driving it around should be OK)




4. PERFORM DOWNHILL ASSIST CONTROL CALIBRATION (w/ Downhill Assist Control)

(b) Enter test mode (when using SST check wire).

(1) Turn the ignition switch off.

(2) Using SST, connect terminals 12 (TS) and 4 (CG) of the DLC3.

Front view of DLC3

(c) Turn the downhill assist control switch off.

(d) Push the downhill assist control switch and check that the downhill assist control indicator light is blinking.

(e) Turn the downhill assist control switch off.

(f) Turn the ignition switch off.

(g) Check if DTC C120A is output.

HINT:

If DTC C120A is not output, calibration was performed successfully.




5. PERFORM CRAWL CONTROL CALIBRATION (w/ Crawl Control)

(2) Using SST, connect terminals 12 (TS) and 4 (CG) of the DLC3.

Front view of DLC3

(c) Push the crawl ON/OFF switch and check that the crawl indicator light is on while the switch is being pushed.

Text in Illustration

*1 Crawl Control Switch

*2 ON/OFF Switch

*3 Speed Selector Switch

*4 Low

*5 Medium-low

*6 Medium

*7 Medium-high

*8 High

(I pushed in the ON/OFF button while I turned the dial and kept pushed down till the end of the following steps)

(d) Turn the crawl ON/OFF switch off.

(e) Turn the speed selector switch to L (low).

(f) Turn the speed selector switch to medium-low.

(g) Turn the speed selector switch to M (medium).

(h) Turn the speed selector switch to medium-high.

(i) Turn the speed selector switch to H (high).

(j) Turn the speed selector switch to L (low).

(k) Turn the ignition switch off.

(l) Check if DTC C120A is output.

HINT:

If DTC C120A is not output, calibration was performed successfully.

Original Post:
As the title suggests, does anyone know how to reset the yaw rate and acceleration sensor back to zero? Ever since I installed my lift, my VSC seems to kick on a little too much, I'm guessing one possibility is due to the fact that the front is now level with the rear.

I just downloaded the Repair Manual, Thanks again Nashman, and on page 522 under the brake control section, it shows that we can have this Yaw Rate and Acceleration Sensor re-calibrated. I did a Google search and found out that many other older 4Runners have had this same problem, after doing a lift, the VSC kicks on too much, they were able to just use a jumper cable between 2 terminal, perform some fancy work with the ignition and and get it back to zero. Here is a link

I'm sure I can take it into a dealer and have them do it, I just prefer not to deal with dealers if it can be helped.

I have no body roll when cornering, yet my truck thinks I'm about to flip over and activate the VSC, slam on the brakes and etc. and it's scary when your on the side of a cliff, and the brakes engage by themselves. I don't in any means drive reckless either.

Thanks,
Nathan

 

[snow&surf]

Sorry but I can't answer your question. I do find it strange that this happens when cornering, maybe new UCAs would help alleviate the VSC response?

 

[iDRiVaT4R]

Thanks for the response, but UCA's I don't think will alleviate it.

I just called the dealership and a Zero-Point recalibration is $95, so if anyone has a work around, that would be Great. This little Yaw Rate and Acceleration Sensor is located under the center console box, just FYI.

 

[harper7]

As the title suggests, does anyone know how to reset the yaw rate and acceleration sensor back to zero? Ever since I installed my lift, my VSC seems to kick on a little too much, I'm guessing one possibility is due to the fact that the front is now level with the rear.

I just downloaded the Repair Manual, Thanks again Nashman, and on page 522 under the brake control section, it shows that we can have this Yaw Rate and Acceleration Sensor re-calibrated. I did a Google search and found out that many other older 4Runners have had this same problem, after doing a lift, the VSC kicks on too much, they were able to just use a jumper cable between 2 terminal, perform some fancy work with the ignition and and get it back to zero. Here is a link

I'm sure I can take it into a dealer and have them do it, I just prefer not to deal with dealers if it can be helped.

I have no body roll when cornering, yet my truck thinks I'm about to flip over and activate the VSC, slam on the brakes and etc. and it's scary when your on the side of a cliff, and the brakes engage by themselves. I don't in any means drive reckless either.

Thanks,
Nathan

This is right out of the repair manual. Number 3 is probably the method used in the yotatech link.
SST stands for SPECIAL SERVICE TOOL
SST 09843-18040 from a little research is supposedly just a jumper wire but you'll need to confirm that.
I've never done zero point calibration before.
Sounds like a possible safety issue......Might be worth a trip to the dealership??
Let us know what you come up with.

Out of the Repair Manual
1. DESCRIPTION
(a) After replacing VSC-related components, clearing and reading the sensor calibration data is necessary.
(b) Follow the chart to perform calibration.

2. PERFORM YAW RATE AND ACCELERATION SENSOR AND STEERING ANGLE SENSOR ZERO POINT CALIBRATION (When Using Techstream)
Connect laptop with Techstream software to the DLC3 -yada-yada-yada

3. PERFORM YAW RATE AND ACCELERATION SENSOR AND STEERING ANGLE SENSOR ZERO POINT CALIBRATION (When Using SST Check Wire 09843-18040)

NOTICE:

While obtaining the zero points, keep the vehicle stationary and do not vibrate, tilt, move, or shake it (do not start the engine).
Be sure to perform this procedure on a level surface (with an inclination of less than 1%).

(a) Clear the zero point calibration data.

(1) Turn the ignition switch off.

(2) Check that the steering wheel is centered.

(3) Check that the shift lever is in P.

(4) Turn the ignition switch to ON.

(5) The ABS warning light and slip indicator light come on for 3 seconds to indicate that the initial check is completed.

(6) Using SST 09843-18040, connect and disconnect terminals 12 (TS) and 4 (CG) of the DLC3 4 times or more within 8 seconds.

(7) Check that the slip indicator light comes on.

(b) Perform zero point calibration of the yaw rate and acceleration sensor.

(1) Turn the ignition switch off.

(2) Check that the steering wheel is centered.

(3) Check that the shift lever is in P.

NOTICE:

DTCs 36 (Zero Point Calibration of Yaw Rate Sensor Undone) and 39 (Zero Point Calibration of Acceleration Sensor Undone) are stored if the shift lever is not in P.
If a DTC is output that indicates zero point calibration is incomplete, repeat the procedure starting at the step for clearing the zero point calibration data and system information.

(4) Using SST , connect terminals 12 (TS) and 4 (CG) of the DLC3.

(5) Turn the ignition switch to ON.

(6) Keep the vehicle stationary on a level surface for 5 seconds or more.

(7) Check that the slip indicator light comes on for several seconds and then blink in the test mode pattern (0.125 seconds on and 0.125 seconds off).

HINT:

If the slip indicator light does not blink, perform zero point calibration again.
The zero point calibration is performed only once after the system enters test mode.
Calibration cannot be performed again until the stored data is cleared.

(8) Turn the ignition switch off and disconnect SST from the DLC3.

(c) Drive the vehicle straight ahead at 40 km/h (25 mph) or more for at least 10 seconds.

Front view of DLC3

 

[Deep_palancar]

Thanks for the response, but UCA's I don't think will alleviate it.

I just called the dealership and a Zero-Point recalibration is $95, so if anyone has a work around, that would be Great. This little Yaw Rate and Acceleration Sensor is located under the center console box, just FYI.

The procedure is documented in the manual for both the techstream and using the jumper wire. In the HTML version it is under Brake Control / Vehicle Stability / Calibration. What page it would be in the pdfs I'm not sure, but it's in there. (get the html version, it's so much easier find things).

I performed the procedure via techstream several months after installing my lift and can attest that the VSC performance was much improved following the recalibration. It takes about 20 minutes and you Must be parked level AND be able to drive off straight and level. I tried to do it and drive off via a sloped driveway and it did not like it.

 

[iDRiVaT4R]

Gary, is there any numbered steps after (c)? Did these steps come from the html version of the Repair Manual? I downloaded that one too but had issues unpacking it. I'll try again tomorrow. This is for our 5th gens right, I found a similar sequence on Toyota120 for the 4th gens.

Thanks again,
Nathan

If I attempt this and it works, all those out there with lifted 4Runner's might want to give it a try also.

 

[harper7]

Gary, is there any numbered steps after (c)? Did these steps come from the html version of the Repair Manual? I downloaded that one too but had issues unpacking it. I'll try again tomorrow. This is for our 5th gens right, I found a similar sequence on Toyota120 for the 4th gens.

Thanks again,
Nathan

If I attempt this and it works, all those out there with lifted 4Runner's might want to give it a try also.

Yep , this is right out of the 5Th repair manual.
There are no more steps after "c" for zero point calibration

Number 4 is
4. PERFORM DOWNHILL ASSIST CONTROL CALIBRATION (w/ Downhill Assist Control)
Number 5 is
5. PERFORM CRAWL CONTROL CALIBRATION (w/ Crawl Control)

 

[SeattleMike]

I downloaded that one too but had issues unpacking it. I'll try again tomorrow.

Use Winzip, I had the same issue.

 

[iDRiVaT4R]

Ok, just downloaded WinZip and it unzipped, thanks.

This is way better then scanning through 4,700 pages or so in the pdf Repair Manual.

I'm still debating if I should maybe just lower the front coilovers a little bit, to bring back some of the stock rake, that might help the VSC act normal again, or I might just perform the recalibration with the check wire as Harper posted, or maybe both.

Ill let everyone know what I end up doing, thanks again for all the help.
Nathan

 

[iDRiVaT4R]

Just to update everyone, I decided to lower the front suspension a little bit and see how that affects the VSC system.

The stock suspension was 2" higher in the rear, after my lift, the rear was only an inch higher.

Post lift, the front measured 23" center of wheel to fender, the rear was 24" so I lowered the front earlier today and I am now at 22 3/8" from center of wheel to fender. My CV boots looked maxed out for lift, which was another reason I decided to lower the front. I don't want to change out the boots more than I have too. My VSC has been kicking in everyday, so I'll let everyone know the output asap. If I still have issues, I'll be performing the check wire calibration that Harper posted earlier.

Thanks again for all the help,
Nathan

 

[iDRiVaT4R]

Well, I attempted a curve today and although I was able to go a little faster, the VCS still kicked in. I went ahead and attempted the Check wire CAlibration and went through all the steps. The second to last step where the lights are supposed to blink to confirm the calibration completed successfully did blink for me. SO I am good there.

I was not able to find a long straight level stretch of road unfortunately. At the moment, the slip indicator light stays lit and I am wondering if its because I was not able to drive straight for 10 seconds doing 25 mph. Deep_palancar is this the issue you were having as well back when you attempted this calibration?

Help from anyone to determine why the slip indicator light stays on would be greatly appreciated. Thanks

 

[iDRiVaT4R]

I GOT IT WORKING :trophy:

I have been stressing out a lot since I attempted this on Monday. I was about to take it to the dealer and pay $95. The other day I did the check DTC check wire trick and I was getting a code of 13. I didn't think much of it actually being a code at the time. Anyways, I have been studing the Repair manual all morning to figure out what to do and found out that the ECU calibration was not completed. Here is what code 13 or C120A is for "The master cylinder solenoid is not informed that the vehicle is equipped with downhill assist control or crawl control and downhill assist control or crawl control operates." So I basically just went out to the truck, did the steps for "5. PERFORM CRAWL CONTROL CALIBRATION (w/ Crawl Control)" and now everything works.

I have no DTC stored, the slip indicator is always off now when driving and I can take turns like a bat out of hell without the VSC kicking in and scaring the crap out of myself and my passengers.

If your VSC kicks in a little too much I highly recommend doing this calibration. Steps are basically the same as Harper posted, but you need to perform steps 4 and 5 if you have Downhill Assist Control or Crawl Control or you will be SOL as I was. They are on the Same page as what harper posted in the Repair Manual file located Brake/Vehicle Stability Control System/Calibration (the 7th option down).

I'll modify my first post in this thread to include the steps. Maybe it can be added as a sticky or in the mods section.

 

[harper7]

I GOT IT WORKING :trophy:

I have been stressing out a lot since I attempted this on Monday. I was about to take it to the dealer and pay $95. The other day I did the check DTC check wire trick and I was getting a code of 13. I didn't think much of it actually being a code at the time. Anyways, I have been studing the Repair manual all morning to figure out what to do and found out that the ECU calibration was not completed. Here is what code 13 or C120A is for "The master cylinder solenoid is not informed that the vehicle is equipped with downhill assist control or crawl control and downhill assist control or crawl control operates." So I basically just went out to the truck, did the steps for "5. PERFORM CRAWL CONTROL CALIBRATION (w/ Crawl Control)" and now everything works.

I have no DTC stored, the slip indicator is always off now when driving and I can take turns like a bat out of hell without the VSC kicking in and scaring the crap out of myself and my passengers.

If your VSC kicks in a little too much I highly recommend doing this calibration. Steps are basically the same as Harper posted, but you need to perform steps 4 and 5 if you have Downhill Assist Control or Crawl Control or you will be SOL as I was. They are on the Same page as what harper posted in the Repair Manual file located Brake/Vehicle Stability Control System/Calibration (the 7th option down).

I'll modify my first post in this thread to include the steps. Maybe it can be added as a sticky or in the mods section.

Great info Nathan!
Thanks for being brave enough to blaze new trails!
So glad your truck is back to normal.

Definitely should do a little write-up or a link to this post in the "Mods and Write-ups" Sticky. I'm sure it will come in handy for years and years!

I wonder what caused yours to be off compared to the others that have lifted. Did you disconnect any wiring or mess with the bleed valves from the KDSS when you did your lift?

 

[iDRiVaT4R]

Harper, I just modified the original post so that readers can get to the steps quickly, and maybe this can become a sticky or something, IDK.

My truck's VSC even before the lift seemed very sensitive to curves. There are a lot of curves going up and down hill to get to the desert where I take it off roading and I have had to always baby it on them. Its very scary when the VSC kicks on at the end of a turn on the side of a cliff, brakes engage and the whole truck shifts its weight towards the cliff. It's definitely got my blood flowing a few times.

 

[snow&surf]

glad you were able to resolve this. i still find it strange your VSC was so sensitive and that you have probably been the only member to experience this who has lifted their truck. thanks for the detailed write-up (in case this happens to my truck down the line).

 

[epinephrine4R]

overly sensitive VSC

I complained to the dealer about the hypersensitive engagement and they actually drove out with me where I documented it for them. Then, their field guy apparently came in and rezeroed things but there was no change. Incidentally, this is a trail edition. They seem to feel that it is a normal response however it really limits the driving experience and it has pulled me into a curve in front of another oncoming truck at least once. Would be nice if Toyota recognizes that there is a problem and offers less aggressive activation.

 

[iDRiVaT4R]

^^ epinephrine4R... Try and attempt this recalibration yourself using the instructions on the first post. After I re-did mine, it kicked in maybe once or twice after. But that was like within a few days of the recalibration. Ever since then though, Mine hasn't kicked in once, I can finally drive it like it was meant to be driven. I was almost to the point of selling the 4Runner because of the hypersensitive VSC system.

Make sure when you recalibrate it your on a flat/level surface. Like I mentioned before, before I re-calibrated it, my VSC would kick in every day at this one turn on the way to work.

But yeah, when your on a two lane road on the side of a cliff cornering and the VSC kicks in, it will scare the SH*T out of you! AS your brakes engage and the vehicle shifts towards the edge, your life literally flashes before your eyes.

Even though the dealer said they re-calibrated it, might be worth trying it yourself if its still too sensitive .The recalibration isn't that hard and will only take you a few minutes if that. If you attempt it and need immediate help PM me.

 

[sandcrawler]

thanks for posting this info, Nathan. my TE is not lifted, but my VSC is definitely over-aggressive. armed with this info i intend to bring it to the dealer for a re-calibration under warranty. wish me luck! thanks again.

 

[iDRiVaT4R]

Let me know how it goes. The dealer wanted $95 to do mine.

Mine was very sensitive prior to the lift, just more so after.

 

[sklett]

...i still find it strange your VSC was so sensitive and that you have probably been the only member to experience this who has lifted their truck...

FWIW, I too suffer from this terrible system! I came across this thread (I realize it's kind of old) while researching the overactive response. I'm up in my local mountains right now and I just about piss myself if I dare to forget to disable it (holding down TRAC button for 5 seconds turns off VSC). Driving back from getting my morning coffee, bird and forest sounds, good melow music on and then "BEEP-BEEP-BEEP!!!" = Moment ruined

I didn't see anyone mention that you can disable VSC so I thought I would post here in case someone else comes across this.