Trac light on after alignment, code C120A?

[Canazes9]

Ok, I need some help. Had the tires rotated during a routine oil change today, the tech noticed a little uneven wear so they checked the alignment. Alignment was off, they aligned, now the Trac light is on and it's getting the error code C120A and it won't clear.

This is a 2013 SR5 4wd. Lifted w/ icon coil overs up front about 2" and about 0.75" in the rear w/ custom Deaver coils and Icon rear shocks. Factory UCA's. The truck has been running this suspension of about 15k miles, no problems to this point.

I have 3 lifted Toyotas: an '07 Tacoma, a '12 Tacoma and this '13 SR5 T4R. This same shop did the lifts for all 3 vehicles, did the alignments for all 3 vehicles, same mechanic for all 3 vehicles. I've been doing business w/ them for about 4 years. They do good work, have never had a problem before.

Same shop, same alignment tech, brought the same vehicle to the same specs 15k miles ago and I had no problems - now the code. Yes, they have a modern Hunter machine that does zero point calibration. They did the zero point calibration twice with the machine, can't clear the code. Then they tried the manual zero point calibration twice w/ the the jumper wire, can't clear the code. Battery has been disconnected multiple times, no effect. Vehicle will go into 4wd/4lo, but no ATRAC.

Any ideas?

David

 

[eddiebx]

Ok, I need some help. Had the tires rotated during a routine oil change today, the tech noticed a little uneven wear so they checked the alignment. Alignment was off, they aligned, now the Trac light is on and it's getting the error code C120A and it won't clear.

This is a 2013 SR5 4wd. Lifted w/ icon coil overs up front about 2" and about 0.75" in the rear w/ custom Deaver coils and Icon rear shocks. Factory UCA's. The truck has been running this suspension of about 15k miles, no problems to this point.

I have 3 lifted Toyotas: an '07 Tacoma, a '12 Tacoma and this '13 SR5 T4R. This same shop did the lifts for all 3 vehicles, did the alignments for all 3 vehicles, same mechanic for all 3 vehicles. I've been doing business w/ them for about 4 years. They do good work, have never had a problem before.

Same shop, same alignment tech, brought the same vehicle to the same specs 15k miles ago and I had no problems - now the code. Yes, they have a modern Hunter machine that does zero point calibration. They did the zero point calibration twice with the machine, can't clear the code. Then they tried the manual zero point calibration twice w/ the the jumper wire, can't clear the code. Battery has been disconnected multiple times, no effect. Vehicle will go into 4wd/4lo, but no ATRAC.

Any ideas?

David

Did they do the last step of the ZPC? (DAC/Crawl control calibration). If you don't accomplish this step the C120A will never clear no matter how many times you do the actual ZPC...

 

[Canazes9]

Did they do the last step of the ZPC? (DAC/Crawl control calibration). If you don't accomplish this step the C120A will never clear no matter how many times you do the actual ZPC...

They did DAC, I don't have crawl control.

Thanks,

David

 

[eddiebx]

They did DAC, I don't have crawl control.

Thanks,

David

Sorry I meant either DAC or crawl control, not both. Did they follow the factory instructions to the T for the DAC calibration? Because if so that might be a problem...I recall the way they wrote the FSM it seems like they forgot to tell you to turn the ignition back to the ON position before pushing the DAC button, lol. This stumped me for quite a while when trying to do my crawl control calibration :frusty:

 

[Canazes9]

Sorry I meant either DAC or crawl control, not both. Did they follow the factory instructions to the T for the DAC calibration? Because if so that might be a problem...I recall the way they wrote the FSM it seems like they forgot to tell you to turn the ignition back to the ON position before pushing the DAC button, lol. This stumped me for quite a while when trying to do my crawl control calibration :frusty:

I don't know for a fact, I can ask tomorrow. I'm going to assume they did as it's the same guy, same equipment performing the alignment 7months later.

I will ask - assuming they did that, any other ideas?

Thanks for your input!

David

 

[eddiebx]

I don't know for a fact, I can ask tomorrow. I'm going to assume they did as it's the same guy, same equipment performing the alignment 7months later.

I will ask - assuming they did that, any other ideas?

Thanks for your input!

David

Oooooh sorry I just reread your original post, I didn't read that you had it done perfectly fine there once already!

Hmm...not really sure what else it can be because I think that the C120A code only indicates that the initialization between the master cylinder solenoid and the DAC is incomplete.

I think in laymen's terms, the master cylinder solenoid and the DAC switch just need to tell each other, hey I'm here and present and accounted for.

The other possibility is that there's an open circuit along the path between the DAC switch and the master cylinder?

If you want be sure and rule out the ZPC, why not try it out yourself right now it's REAL simple and almost impossible to screw up as long as you have a flat surface

 

[Canazes9]

Oooooh sorry I just reread your original post, I didn't read that you had it done perfectly fine there once already!

Hmm...not really sure what else it can be because I think that the C120A code only indicates that the initialization between the master cylinder solenoid and the DAC is incomplete.

I think in laymen's terms, the master cylinder solenoid and the DAC switch just need to tell each other, hey I'm here and present and accounted for.

The other possibility is that there's an open circuit along the path between the DAC switch and the master cylinder?

If you want be sure and rule out the ZPC, why not try it out yourself right now it's REAL simple and almost impossible to screw up as long as you have a flat surface

I've got guests coming in a little while, no time to fool with it this evening. I will try tomorrow. Thanks for your help!

David

 

[1engineer]

I've got guests coming in a little while, no time to fool with it this evening. I will try tomorrow. Thanks for your help!

David

David this is one thing you have to do yourself so you can make sure its done right. This will eliminate any question. Follow the instructions above if nothing else for troubleshooting purposes.

 

[Scott@Hightech]

What are they using to calibrate the system? The alignment machine has nothing to do with the calibrations. You have to use a tech stream or other capable Scan tool. And they/you need to do 3/4 functions in the ABS module for it to work properly.

1. You need to use the "reset memory" function which will clear any current learned settings.
2. "test mode" which calibrates the VSC
3. "calibrate DAC"
And you said you don't have crawl control but that would be the final step if equipped.


Neglecting the first step often causes frustration as they don't like to overwrite information for some reason.

 

[Canazes9]

David this is one thing you have to do yourself so you can make sure its done right. This will eliminate any question. Follow the instructions above if nothing else for troubleshooting purposes.

Will do - I am friends with the shop owner and shop Manager, showed them this thread and we'll go over it together again tomorrow.

What are they using to calibrate the system? The alignment machine has nothing to do with the calibrations. You have to use a tech stream or other capable Scan tool. And they/you need to do 3/4 functions in the ABS module for it to work properly.

1. You need to use the "reset memory" function which will clear any current learned settings.
2. "test mode" which calibrates the VSC
3. "calibrate DAC"
And you said you don't have crawl control but that would be the final step if equipped.


Neglecting the first step often causes frustration as they don't like to overwrite information for some reason.

Thanks for your input Scott - I'm talking a little out of my league here, as I'm not that familiar with their equipment. Their alignment machine has some diagnositic/code reading/clearing capabilities. It plugs into the computer and their is a stepwise procedure for reading, reviewing and clearing codes. The shop owner showed me print outs from their machine. I remember seeing something about the test mode and about "calibrate DAC". Not sure about the first part, I'll show them this tomorrow and make sure. I appreciate the help!

David

 

[Canazes9]

Zero pt calibration, DAC calibration completed multiple times. Manually, plugged in the machine, ran it several times - can't get the slip indicator light off. Guess I will have to make an appointment and bring it in to the dealer.

David

 

[eddiebx]

Zero pt calibration, DAC calibration completed multiple times. Manually, plugged in the machine, ran it several times - can't get the slip indicator light off. Guess I will have to make an appointment and bring it in to the dealer.

David

That's a real bummer...

David, I hate to sound like a broken record here but if you have the time, I urge you to try performing the ZPC one more time by yourself. All you need is a relatively flat surface, one piece of wire and it literally takes 30 seconds once you memorize the few steps. There's also absolutely nothing you can screw up more (unless you jumper the two wrong pins, lol), so really nothing to lose at this point.

The reason I am so adamant about it is because all of the signs of an improper ZPC are there (no disrespect to your tech of course, this procedure is just really finicky IMO). If you had no C120A DTC going into this alignment there is no other reason it would magically appear, unless the signal between the DAC button and the master cylinder solenoid just happen to break recently.

Here is the thread in case you haven't had a chance to find it: http://www.toyota-4runner.org/5th-g...celeration-sensor-zero-point-calibration.html

Few tricks that I think will make your life easier is...don't worry about the drive straight ahead for 20 seconds part, until after you are done with all the steps. And also, don't worry about driving straight ahead...I've tried it every which way (forwards, backwards, in a circle, you name it) and none of them seem to make a difference.

I know the instructions seem daunting at first, but it really boils down to just a few simple steps. First you find the two pins on the OBD2 service port...now with the ignition in the ON position, you connected it and disconnect it quickly a few times, which will cause your slip light to come on (this signifies that you've successfully cleared all the data).

Now, turn it off, connect the two pins securely with the jumper wire and then turn the ignition switch back to the ON position; you should see the slip light start flashing rapidly shortly after (which means the ZPC data has been stored).

Turn it off again, leave the jumper connected, then turn it right back to the ON position. Now this part differs a tiny bit because I have crawl control and you have DAC, but I believe you just press your DAC button a few times to make sure the little "4runner driving down a mountain" indicator goes on and off in your gauge cluster every time you press it.

Turn off the ignition, remove the jumper wire, start her up and go for a spin around the block and you're done!

I really hope this resolves your issue, but if not, at least you're certain it's something that requires a trip to the dealer. Feel free to post or PM me if you get stuck on any certain steps, I'll try to walk you through it the best I can :cheers:

 

[Canazes9]

That's a real bummer...

David, I hate to sound like a broken record here but if you have the time, I urge you to try performing the ZPC one more time by yourself. All you need is a relatively flat surface, one piece of wire and it literally takes 30 seconds once you memorize the few steps. There's also absolutely nothing you can screw up more (unless you jumper the two wrong pins, lol), so really nothing to lose at this point.

The reason I am so adamant about it is because all of the signs of an improper ZPC are there (no disrespect to your tech of course, this procedure is just really finicky IMO). If you had no C120A DTC going into this alignment there is no other reason it would magically appear, unless the signal between the DAC button and the master cylinder solenoid just happen to break recently.

Here is the thread in case you haven't had a chance to find it: http://www.toyota-4runner.org/5th-g...celeration-sensor-zero-point-calibration.html

Few tricks that I think will make your life easier is...don't worry about the drive straight ahead for 20 seconds part, until after you are done with all the steps. And also, don't worry about driving straight ahead...I've tried it every which way (forwards, backwards, in a circle, you name it) and none of them seem to make a difference.

I know the instructions seem daunting at first, but it really boils down to just a few simple steps. First you find the two pins on the OBD2 service port...now with the ignition in the ON position, you connected it and disconnect it quickly a few times, which will cause your slip light to come on (this signifies that you've successfully cleared all the data).

Now, turn it off, connect the two pins securely with the jumper wire and then turn the ignition switch back to the ON position; you should see the slip light start flashing rapidly shortly after (which means the ZPC data has been stored).

Turn it off again, leave the jumper connected, then turn it right back to the ON position. Now this part differs a tiny bit because I have crawl control and you have DAC, but I believe you just press your DAC button a few times to make sure the little "4runner driving down a mountain" indicator goes on and off in your gauge cluster every time you press it.

Turn off the ignition, remove the jumper wire, start her up and go for a spin around the block and you're done!

I really hope this resolves your issue, but if not, at least you're certain it's something that requires a trip to the dealer. Feel free to post or PM me if you get stuck on any certain steps, I'll try to walk you through it the best I can :cheers:

Eddie,

I do appreciate the help! I was sitting in the car when we did it this time, reading through the steps in the procedure while the shop owner went through it. We tried everything I could think of, even tried once with the truck in 4lo - we couldn't make the DAC light come on. Open to additional suggestions, I just don't know what to do at this point other than take it to the dealer.

David

 

[1engineer]

Hey David, I remember a thread awhile back and while it was not exactly your problem it goes through the trials and tribulations and shows what can happen even with dealer involvement. Its a good read and took forever to find it so here you go. http://www.toyota-4runner.org/5th-g...n-trail-edition-traction-control-problem.html hope it helps.

 

[Scott@Hightech]

I have had issues like this before, The solution was to use a different scan tool. Did the exact same steps and everything but for whatever reason the other tool worked.

Also another longshot, but it is possible that the alignment, toe specifically is not correct( steering rack not centered) and that isnt allowing it to work.

Last tip, try disconnecting the battery for 30 min before trying the calibrations.

 

[eddiebx]

Eddie,

I do appreciate the help! I was sitting in the car when we did it this time, reading through the steps in the procedure while the shop owner went through it. We tried everything I could think of, even tried once with the truck in 4lo - we couldn't make the DAC light come on. Open to additional suggestions, I just don't know what to do at this point other than take it to the dealer.

David

Hmm...the only other thing I can think of to suggest to you is to do the ZPC over again.... :jk: :jk: :jk:

Sounds like you guys tried your best, I'm sure the dealer can figure out for ya!

Please report back because I'd be interested to hear what's the root cause.

 

[Scott@Hightech]

Was this resolved?

 

[Canazes9]

Was this resolved?

Not yet - last week sucked for me work wise. I took a lot of time off at the end of '13. No vacation goes unpunished, in the last two weeks I have driven 2100 miles and had to go on a 3 day trip to the mid west. That's a bit much even for me! This upcoming week doesn't suck so bad, I'll be at the dealership 1st thing tomorrow morning, have an appointment for 8am.

I'll post a follow-up afterwards....

David

 

[Canazes9]

Was this resolved?

This week's winter weather through a kink in my plans to get the 4Runner looked at early, but I was finally able to get it to the dealership this morning. Unfortunately, I did not get the opportunity to talk to the service tech that actually worked on my vehicle and the ticket leaves me a little confused:

7777 Reinitialize ABS system
10196 CPT

They charged me $49.88, had me in and out in about 30 minutes. Is this Toyota coding for a zero pt calibration? If not, what did they do?

Regardless, light is off now, all is well.

David

 

[eddiebx]

This week's winter weather through a kink in my plans to get the 4Runner looked at early, but I was finally able to get it to the dealership this morning. Unfortunately, I did not get the opportunity to talk to the service tech that actually worked on my vehicle and the ticket leaves me a little confused:

7777 Reinitialize ABS system
10196 CPT

They charged me $49.88, had me in and out in about 30 minutes. Is this Toyota coding for a zero pt calibration? If not, what did they do?

Regardless, light is off now, all is well.

David

Sounds awfully close to the problem we initially thought we had...to the best of my understanding the last step of the ZPC that was needed to be performed was to initialize the master cylinder solenoid by making it aware of your DAC control option. Basically, so it knows to operate the ABS to do all the nifty brake pedal modulating and good stuff when you're using ATRAC and DAC.

But hey, a few bucks for some extra peace of mind is just fine in my book. Heck, I'm just glad you finally got that straightened out, and glad that it didn't end up to be anything serious