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Discussion Starter · #1 ·
I started having trouble with the VSC TRAC lights. I was getting random grabbing on left rear. I may have a bad speed sensor there, but I wanted to share what I have learned.

There are 3 pins on the OBDII connector you will use, Ts, Tc, and CG.

The pins are arranged like:
......__......
XXXXXXXX
XXXXXXXX

The underscore show the alignment tab. The pins are located here

Ts = 1
Tc = 2
CG = 3

.....__.....
XX12XXXX
XXXX3XXX sorry for the crude dwg. Look to see where pins are it helps. It isn't full.

NOTE: I made a test tool with 3 wires and a SPDT switch with ON-OFF-ON function. You can label one Ts and one Tc. You can put the wires in the connector and you can use the switch to select or disconnect. You don't have to crawl around so much.

To check code
1. Short Tc and CG
2. Start engine
3. VSC will blink code(s) in order with a space between.
4. If it is flashing evenly and rapidly there is no code.
5. turn off, remove jumper

To clear code (you can't do it by disconnecting battery or with code reader)
1. Short Tc and CG
2. Start engine
3. Press brake pedal 8 times within 5 seconds
4. codes are clear, turn off and remove jumper.

Zero point Calibration ZPC
1. Center steering wheel
2. Short Ts and CG
3. Start engine and wait 4 sec
4. move steering wheel more than 5 deg and then re-center.
5. quickly press TRAC OFF button 3 times (within 3 sec)
6. long beep = success ZPC complete
7. turn off remove jumper

To check deceleration sensor, yaw sensor, brake master cyl sensor, steering angle sensor and speed sensors, do the following: (very tricky, it may take several times, ZPC must be complete and good, use level surface)

1. Short Ts and CG
2. Start engine wait 4 sec
3. Drive straight 3mph
4. Turn fairly sharply (don't let wheels spin or slide) 180deg to parallel to starting position within 5 deg.
5. Stop and put in park.
6. You should hear short beep during turn. This means decel sensor good.
7. You should hear long beep when put in P. This means yaw sensor good.
8. Engine still running and in Park.
9. Take foot off brake for 1 sec.
10. Press brake all the way down and hold.
11. Long beep means master cyl pressure sensor good. Release brake.
12. Turn steering wheel ALL the way left or right, hold 1 sec.
13. Turn steering wheel ALL the way to the other side, hold 1 sec.
14. Long beep means steering angle sensor good.
15. Engine running, in park, wheel straight.
16. Put in drive and drive straight (It is OK if you maneuver a bit to get on a road)
17. Go 30mph for 10-15sec and ABS light should turn off.
18. This means speed sensor works.
19. Stop somewhere safe, put in Park and short Tc and CG. This will show codes of any problems.
20. If all indicators are flashing rapidly and evenly, there are no codes.
21. Turn off and remove jumper.
NOTE: Turning the key off with the Tc and CG shorted will clear other codes.

I hope this helps. You need to do this if you do anything significant with steering, suspension, or with any ABS or TRAC parts or controllers.

WARNING This is a SAFETY issue and you should have the dealer do this, especially if you aren't 100% sure what you are doing or if you don't have significant time to work on the problem. I assume no responsibility for correctness in the procedure or its application. BE CAREFUL. This comes from the 2001 service manual. I think procedures are different for other models.
 

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Discussion Starter · #2 ·
VSC ABS TRAC Codes

I should have posted these

Codes shown by ABS light
71 low volt right front
72 """ " left front
73 Low volt right rear
74 low volt left rear
75 abnormal change rf
76 abnormal chg lf
77 abnormal chg rr
78 abnormal chg lr
79 Deceleration sensor faulty
81 Master cyl press sensor bad

Codes shown by VSC TRAC
71 Yaw rate sens malfunc
72 Steering pos sens malfunc

Codes from ABS light
31 rf spd sens malf
32 lf spd sens malf
33 rr spd sens malf
34 lr spd sens malf
21 Malf ABS and VSC solenoid valves
11 Open or short circ ABS VSC relay circ
41 Low/High battery voltage
49 Open circ stop light sw
51 Pump mtr locked
37 Different tire size(s)
48 Center diff lock circ malf
ABS always ON is skid control ECU problem

Codes from VSC TRAC light
53 ECM communication malf
43 ABS control malf
31 Steering angle sens malf
32 Decel sens malf
34 Yaw rate sens malf
11 Open or short in brake booster circ
12 Open or short in brake inhibit relay circ
61 Master cyl press sens malf
62 Abnormal battery voltage VSC sensor
36 Malf in sensor set value (VSC sens system)
63 Malf in booster pedal force switch


Once you have shorted Tc and CG, the instrument panel will look like Christmas lights. The ones flashing steady and rapidly are OK. The ones with codes will be slow and will count the digits with longer spaces between multiple codes.

Good Luck!!!
 

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You should also post the flashing pattern especially the pattern when there is no error code. Or better yet, just post the PDF file with all the nice graphics.
 

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@mcmatt, I'm assuming the procedure you wrote up was for a 2WD Sequoia, correct? (TRAC OFF vs VSC OFF)

FYI, if performing the ZPC for a 4WD, the manual indicates that the vehicle must be in P and L4 gear. VSC OFF would be pressed instead of TRAC OFF.

Otherwise, great write-up for those that don't have a Toyota DTC tester.
 

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I have two questions regarding this ZPC procedure because I can't seem to get it to work after replacing the yaw rate sensor.

1) Are the Ts (=1) and Tc (=2) switched and shifted over one slot?

.....__.....
XX12XXXX
XXXX3XXX

should the above diagram be this instead?

.....__.....
XXX21XXX
XXXX3XXX


2) For 4WD Sequoias, should it be in P(ark) and NOT in L4 instead of in L4?
 

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My 2002 Sequoia has had the trac/vsc light on for the last 6 months. Now that winter is here I needed to get it fixed. Since I don't have the tools to check all the toyota specific sensors for VSC, I had to take it to the dealer.

After wasting an hour at the dealer and arguing with the mechanic and the service writer about a battery terminal that "should" be replaced, but not really needed, and them refusing to do the recalibration until I fixed the terminal(which of course they were going to charge extra). I explained in high detail how there was no possible way that was the problem. They then proceeded to tell me that they had to check the 4x4 and that would take at least an hour. ARE YOU KIDDING ME? I told them if they did not even look at the VSC right then and there, that I wouldn't bring it back, my total bill was going to be up into the $500 range if they had their way. After some further arguing they told me they wouldn't charge me for the days service, and to bring it back after I fixed the terminal, but they were still going to have to check the 4x4 first before they could check the VSC. NOT ON YOUR LIFE BUDDY!!!

I went ahead and used this method and it worked flawlessly, and the only cost to me was a fraction of a cent paper clip. Thanks toyota for adding in this feature!
 

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2) For 4WD Sequoias, should it be in P(ark) and NOT in L4 instead of in L4?
Per the manual, it says to be IN L4 and Park. I haven't performed it. Just repeating what the manual says.

SuperRunner, do you have 4WD and did you perform the ZPC in Park AND L4?
 

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Per the manual, it says to be IN L4 and Park. I haven't performed it. Just repeating what the manual says.

SuperRunner, do you have 4WD and did you perform the ZPC in Park AND L4?
Yes I am 4WD.

I did NOT use the L4, from what I get, that is only to register a traction control unit with the ECU. Since I was running the same unit, this should not need to be done. Although if the steps above didn't work I would have tried it anyway.
 

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I have the brake, abs, vsc-off, vsc-trac lights on, I tried to Short Tc and CG pins but the only light will blink is the door open light!, what does it mean?.

i did zero point calibration and got the long beep, but the lights are still on.

please help me
 

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I tried both, with key on and starting engine but all the lights keep on,
I also tried to clear codes with brake pedal, but same thing here

am I doing something wrong?
 

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I tried both, with key on and starting engine but all the lights keep on,
I also tried to clear codes with brake pedal, but same thing here

am I doing something wrong?
I am having the same problem. Cruise light also light up but cannot get VSC light to blink. Did you find a fix for the problem?
 

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I used this proceedure for zero point calibration with the pinning used by mcmatt above and it work flawlessly the first time. I DO have a 4wd and did NOT have it engaged while performing the proceedure. The only difference is the labeling of the TRAC OFF/VSC OFF button on the dash. The proceedure couldn't have been more simple, thanks for posting.
 

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Now I know how Romo feels on Monday:)
Nice write-up and Thanks! That obviously took some time to do and then put it down in words for us to understand.
 

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Hey All,

I apologize in advance for dragging up an old thread, but it has lots of great information...

I installed 265/70 tires on the factory wheels of my 2005 4WD Sequoia LTD right before a recent road trip to the mountains. I love the taller tires, but my VSC system is now activating during sharp curves, and it didn't activate so quickly before I installed the new tires.

I assume I need to complete a zero point calibration, which leads to a couple of questions.

  1. Will a zero point calibration fix my VSC issue?
  2. Is the procedure for the 2001 included in this thread applicable to my 2005?
  3. I've never messed with the OBDII plug before. Do I need to buy a OBDII scanner to perform this procedure, or can I just stick a piece of wire into the terminals to short out the pins? In a previous post, SuperRunner seemed to indicate he used a paperclip:)

Thanks,

Steve
 

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Discussion Starter · #20 ·
Hello Steve,

Not sure if the exact procedure will work on the 2005 or not. I think that was before the redesign, however.

The zero point will probably help. Going from straight to 180deg radius gives the computer a calculation on revolutions related to turning which would incorporate the new wheel size, it seems anyway.

An OBDII scanner won't help you. They are only meant for the "public" area of the EVAP codes and ECU variables. They don't do OEM specific functions like body computers, etc.

I made small harness with some male pins that fit the connector holes and a DPDT switch. If I switch it one way it makes one connection and if I switch it the other way it makes the other connection. This made it very easy to do the procedures and remain sitting in the driver's seat instead of having to crawl down and reposition every time.

Best of luck
 
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