Fix for ABS, VSC TRAC, VSC OFF, & Brake lights remain on no CEL, or how to repair an ECU (3 Viewers)

[Lexusmech]

Glad you got it figured out and thanks for adding the additional info to help others that might have the same situation.

@FJRyder Hi...2002 SC430 53K miles...I ordered the resonator and removed the old one, but accidentally trashed the pads and the 189 resistor next to it. My resonator did test 8.7k ohms on center to right pin, left pin to center was 1 as well as both outer pins. See pictures. I can't locate the resistor on Newark (its a 18G ohms I think). I am fairly sure its the same resistor on your board. I noticed in your repair picture your resistor was mounted upside down when you installed the larger resistor. The resistor's close proximity seems prone to needing resoldering. So what to do next. Any Ideas?

 

[Lexusmech]

Hi @FJRyder Could you help me identify the 189 resistor so I can search for it? Thanks!

 

[FJRyder]

@FJRyder Hi...2002 SC430 53K miles...I ordered the resonator and removed the old one, but accidentally trashed the pads and the 189 resistor next to it. My resonator did test 8.7k ohms on center to right pin, left pin to center was 1 as well as both outer pins. See pictures. I can't locate the resistor on Newark (its a 18G ohms I think). I am fairly sure its the same resistor on your board. I noticed in your repair picture your resistor was mounted upside down when you installed the larger resistor. The resistor's close proximity seems prone to needing resoldering. So what to do next. Any Ideas?

Ouch!! That Bites! So it looks like the right resonator PCB pad is missing as well as one of the PCB pads for the resistor.
It looks like you used soldering irons which is always difficult on surface mount devices. It best to use a hot air rework station for SMT.

Not all is lost, I think. If you don't still have the resistor, you can buy more, they are cheap. The marking is 681, which translates to 680ohms. And I believe this is a 0603 case size.
From Newark: https://www.newark.com/panasonic/erj-h3gj681v/resistor-680r-0-125w-thick-film/dp/29AJ0584?st=680
From Digikey: https://www.digikey.com/en/products/detail/panasonic-electronic-components/ERJ-H3EF6800V/13878043

With the right resonator pad missing, you'll have to use the resistor on an angle to reach the resonator pin. Then use sufficient solder solder to bridge the connection.
Something like what I have poorly drawn below.

.

Of course the resistor must make contact with the resonator lead. You'll also have to be careful to not short anything out with the solder.
If you can control the temperature/wattage of the soldering irons, try the lowest wattage you have as to not pull off the remaining PCB pads.
Too much heat for too long is what caused the pads to lift in the first place.
Also find smaller tips for the soldering iron. They are better for working with SMT devices and will naturally limit the amount of heat delivered as there is less metal.

Good luck and let me know if you have more questions.

 

[Lexusmech]

Ouch!! That Bites! So it looks like the right resonator PCB pad is missing as well as one of the PCB pads for the resistor.
It looks like you used soldering irons which is always difficult on surface mount devices. It best to use a hot air rework station for SMT.

Not all is lost, I think. If you don't still have the resistor, you can buy more, they are cheap. The marking is 681, which translates to 680ohms. And I believe this is a 0603 case size.
From Newark: https://www.newark.com/panasonic/erj-h3gj681v/resistor-680r-0-125w-thick-film/dp/29AJ0584?st=680
From Digikey: https://www.digikey.com/en/products/detail/panasonic-electronic-components/ERJ-H3EF6800V/13878043

With the right resonator pad missing, you'll have to use the resistor on an angle to reach the resonator pin. Then use sufficient solder solder to bridge the connection.
Something like what I have poorly drawn below.
View attachment 3238636.

Of course the resistor must make contact with the resonator lead. You'll also have to be careful to not short anything out with the solder.
If you can control the temperature/wattage of the soldering irons, try the lowest wattage you have as to not pull off the remaining PCB pads.
Too much heat for too long is what caused the pads to lift in the first place.
Also find smaller tips for the soldering iron. They are better for working with SMT devices and will naturally limit the amount of heat delivered as there is less metal.

Good luck and let me know if you have more questions.

Hi @FJRyder LOL....I was reading the resistor's value upside down. I do have a new cheap narrow tip iron. Not tinning it properly, improper flux, no magnification and no effective wicking of the solder was my downfall. Probably nowhere in South Florida to buy a hot air rework tool on a Saturday. At least a 680ohm resistor is easier to find than a 18Gohm, still can't believe I read it upside down. Likely I will just order the air tool and resistor online. Thanks for your expertise!!

 

[LndXrsr]

Holy crap this worked! Was super nervous about the process, but with a hot air rework gun it came off after a while. Never done anything like this before. My original ceramic resonator came off in a couple pieces, which never bodes well. I just set the new resonator on top of the board and got things liquid again until it set up on there. Warning lights out as soon as I plugged back into the truck. Thanks for this thread! Merits a sticky in my book!

My personal hack job, critique away:

 

[Lexusmech]

Hi @FJRyder LOL....I was reading the resistor's value upside down. I do have a new cheap narrow tip iron. Not tinning it properly, improper flux, no magnification and no effective wicking of the solder was my downfall. Probably nowhere in South Florida to buy a hot air rework tool on a Saturday. At least a 680ohm resistor is easier to find than a 18Gohm, still can't believe I read it upside down. Likely I will just order the air tool and resistor online. Thanks for your expertise!!

Hi @FJRyder I received the resistor and decided to take it all to an PCB board repair shop. Repair shop told me the parts were expensive until I produced the Newark parts, then they settled on a labor charge of $90 to complete the repair. I checked continuity and installed the repaired unit, checked the connectors and reconnected the negative battery cable. Upon engine start I noticed right away the VSC & VSC OFF lights were on now, I did not have these lights on before, just the Brake & ABS lights were on. A code read now shows codes C0205 front driver speed sensor, C0210 rear passenger speed sensor and C1223 ABS Control System Malfunction. I am no longer getting code B1282 Skid Control ECU Communication Stop,. So the fact that I now am getting speed sensor codes seems encouraging and tells me that the Skid Control ECU is now working. I will replace the rear passenger speed sensor. I purposely had the front driver speed sensor unplugged due to previous troubleshooting. The repair work looks a bit messy, the new resistor is covered in glue to secure it down due to the missing pads. See attached pictures. I hope the new rear speed sensor, a code clear and test drive will reset the warning lights and hopefully also eliminate the stiff steering. Finger crossed this works. Will update when done. Thanks!!!

 

[FJRyder]

Holy crap this worked! Was super nervous about the process, but with a hot air rework gun it came off after a while. Never done anything like this before. My original ceramic resonator came off in a couple pieces, which never bodes well. I just set the new resonator on top of the board and got things liquid again until it set up on there. Warning lights out as soon as I plugged back into the truck. Thanks for this thread! Merits a sticky in my book!

My personal hack job, critique away:

Nice work for your for your first time!

I've had several of the old resonators fall apart like your old one did. That's more of a function of the amount of heat and time placed on the lid as its just an epoxy holding it together.

It looks a little low on solder as there appears to be gaps between the board and the component. But I wouldn't be too worried about it as it should last you another ten years or so .

 

[FJRyder]

Hi @FJRyder I received the resistor and decided to take it all to an PCB board repair shop. Repair shop told me the parts were expensive until I produced the Newark parts, then they settled on a labor charge of $90 to complete the repair. I checked continuity and installed the repaired unit, checked the connectors and reconnected the negative battery cable. Upon engine start I noticed right away the VSC & VSC OFF lights were on now, I did not have these lights on before, just the Brake & ABS lights were on. A code read now shows codes C0205 front driver speed sensor, C0210 rear passenger speed sensor and C1223 ABS Control System Malfunction. I am no longer getting code B1282 Skid Control ECU Communication Stop,. So the fact that I now am getting speed sensor codes seems encouraging and tells me that the Skid Control ECU is now working. I will replace the rear passenger speed sensor. I purposely had the front driver speed sensor unplugged due to previous troubleshooting. The repair work looks a bit messy, the new resistor is covered in glue to secure it down due to the missing pads. See attached pictures. I hope the new rear speed sensor, a code clear and test drive will reset the warning lights and hopefully also eliminate the stiff steering. Finger crossed this works. Will update when done. Thanks!!!

Nice recovery on this! Who cares how it looks as long as its working. It will be hidden away and you'll never need to look at it .
Too bad you had to take it to a shop to fix but I'm guessing you still came out ahead overall.

Sounds like the SC430 has a different symptom for the same issue as all the ones I've seen for LX470 and LCs are that the VSC & VSC OFF lights are illuminated.
I'm also a little surprised that you saw this on a vehicle with only 53k on it. Must mean that the issue is more of a function of time and perhaps the local climate?

I don't think this would resolve the stiff steering. That's more likely power steering pump issues or something with the rack and pinion.

 

[Grond]

Hi @FJRyder, thanks for putting this thread together, it's extremely helpful and informative.
I think I may have the same issue as you described, but with one difference. My ABS, Brake, Active Trac, and VSC Trac lights are on, but my VSC OFF light is not illuminated. I don't have Techstream, but have a friend who has another tool called Autoengenuity. He was able to see that there was an ABS and traction control but was not able to communicate with it. I tried jumping the connectors in the diagnostic port under the hood, but no codes were being displayed at all. Planning on trying the resonator fix, as I design and assemble circuit boards for work. But I wanted to make sure that not having the VSC OFF light on could possibly mean something else. I can't find anywhere where this light isn't on in conjunction with the others, so maybe the bulb is just burnt out??
Thanks!

 

[FJRyder]

Hi @FJRyder, thanks for putting this thread together, it's extremely helpful and informative.
I think I may have the same issue as you described, but with one difference. My ABS, Brake, Active Trac, and VSC Trac lights are on, but my VSC OFF light is not illuminated. I don't have Techstream, but have a friend who has another tool called Autoengenuity. He was able to see that there was an ABS and traction control but was not able to communicate with it. I tried jumping the connectors in the diagnostic port under the hood, but no codes were being displayed at all. Planning on trying the resonator fix, as I design and assemble circuit boards for work. But I wanted to make sure that not having the VSC OFF light on could possibly mean something else. I can't find anywhere where this light isn't on in conjunction with the others, so maybe the bulb is just burnt out??
Thanks!

An easy check to see if the bulb is burned, when you first switch the key to on, all the lights should turn on for 1-2 seconds.

But yeah, it does sound like the same issue.
The next check before replacing is to ohm out the resistance on the resonator between the three terminals. Needle tipped probes work best for this as there is a coating to prevent corssion. When measured in the circuit, left pin to center pin should be open or Mohms, Left pin to right pin should be open or Mohms, center pin to right pin should be ~8.7kohm.

 

[Grond]

An easy check to see if the bulb is burned, when you first switch the key to on, all the lights should turn on for 1-2 seconds.

But yeah, it does sound like the same issue.
The next check before replacing is to ohm out the resistance on the resonator between the three terminals. Needle tipped probes work best for this as there is a coating to prevent corssion. When measured in the circuit, left pin to center pin should be open or Mohms, Left pin to right pin should be open or Mohms, center pin to right pin should be ~8.7kohm.

The bulb is definitely out, thanks for the tip. Probing the board with my super cheap DMM, I'm getting 1.2 Mohm across right and left, 8.3kohm across right and center, and 1.2 Mohm across left to center. So it seems like this isn't the fix. I wonder if the bulb being out could affect it? I read on some other forums that the P indicator bulb being out caused all the lights to turn on?

 

[FJRyder]

Sounds like the resonator might be ok.
I would try doing a Zero Point Calibration next to see if that could be the issue.

Paper clip method:

Paperclip method for zero point calibration

I've read through every post on MTS/CC install, and I'm about to do it myself. The only thing I cant find is more details on the paperclip method for the zero point. I see several people have done it successfully, and I've watched a few videos. The thing I'm curious about is how you do the whole...

forum.ih8mud.com

When to do it:

Zero Point Calibration

It's not talked about on this site, but it's a thing in almost all Toyota/Lexus models - zero point calibration. I have not researched this topic enough to understand it fully, but it's generally recommended after any sort of suspension, alignment, steering rack work, that a zero point...

forum.ih8mud.com

 

[Grond]

Sounds like the resonator might be ok.
I would try doing a Zero Point Calibration next to see if that could be the issue.

Paper clip method:

Paperclip method for zero point calibration

I've read through every post on MTS/CC install, and I'm about to do it myself. The only thing I cant find is more details on the paperclip method for the zero point. I see several people have done it successfully, and I've watched a few videos. The thing I'm curious about is how you do the whole...

forum.ih8mud.com

When to do it:

Zero Point Calibration

It's not talked about on this site, but it's a thing in almost all Toyota/Lexus models - zero point calibration. I have not researched this topic enough to understand it fully, but it's generally recommended after any sort of suspension, alignment, steering rack work, that a zero point...

forum.ih8mud.com

Just reinstalled the ECU, and after plugging everything back in, the lights are off. Hopefully that means it was just a loose connection somewhere. Does unplugging it reset the codes? Maybe if I start to drive it they'll come back on... If so I'll try the zero point calibration

 

[FJRyder]

Just reinstalled the ECU, and after plugging everything back in, the lights are off. Hopefully that means it was just a loose connection somewhere. Does unplugging it reset the codes? Maybe if I start to drive it they'll come back on... If so I'll try the zero point calibration

No, unplugging does not reset the codes. I have received ECUs from people with their codes still present in the memory.

Could be a few things:
1) Lose connection
2) Resonator is intermittent
3) Yaw sensor issue? - This seems less likely

 

[Grond]

No, unplugging does not reset the codes. I have received ECUs from people with their codes still present in the memory.

Could be a few things:
1) Lose connection
2) Resonator is intermittent
3) Yaw sensor issue? - This seems less likely

Just drove it down the street and the A-Trac kicked in and flashed whenever I accelerated... None of the ABS, VSC, or brake lights are back on though. Any thoughts?

 

[FJRyder]

Just drove it down the street and the A-Trac kicked in and flashed whenever I accelerated... None of the ABS, VSC, or brake lights are back on though. Any thoughts?

Sounds more like a wheel position senor or maybe the resonator is intermittent.
I would suggest getting the ~$40 cable and TechStream How-To: TechStream In 5 Minutes - https://forum.ih8mud.com/threads/how-to-techstream-in-5-minutes.1034923/

mini-vci cable for sale | eBay

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This is the best method for reading codes directly from the ABS/SKID ECU. You'll also be able to ready the wheel position sensors in real time.

 

[Grond]

Sounds more like a wheel position senor or maybe the resonator is intermittent.
I would suggest getting the ~$40 cable and TechStream How-To: TechStream In 5 Minutes - https://forum.ih8mud.com/threads/how-to-techstream-in-5-minutes.1034923/

mini-vci cable for sale | eBay

Get the best deals for mini-vci cable at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items!

www.ebay.com

This is the best method for reading codes directly from the ABS/SKID ECU. You'll also be able to ready the wheel position sensors in real time.

I used the diagnostic jumper now that I have connection to the ABS ECU, and I'm getting codes. Looks like code 46 for ABS, and 43 and 47 for VSC. I don't see those documented in the youtube video showing how to diagnose ABS codes. Anyone know what these values mean?

 

[Mdej3]

100% recommend @FJRyder service.
Used in one of my costumers and he did wonders, and FAST!
Thank you again!!!
Manny @ Tampa Cruisers.

 

[FJRyder]

I used the diagnostic jumper now that I have connection to the ABS ECU, and I'm getting codes. Looks like code 46 for ABS, and 43 and 47 for VSC. I don't see those documented in the youtube video showing how to diagnose ABS codes. Anyone know what these values mean?

Brake system code

2004 GX470, 133k miles; on rare occasions, I get ABS, VSV TRAC and VSV OFF lights on. They typically go off by themselves after a little while, in the same drive cycle. Gas cap pretty new, just went through Louisiana testing without a hitch. Lexus sez there's a code C1246, skid control ECU...

forum.ih8mud.com

I have fixed a few ECUs that did not appear to have a bad resonator, ohmed out ok/worked fine in my LC. But after replacing and sending back appeared to fix the issue. Its definitely more cost effective than replacing a master cylinder.

ABS Code 43 - Deceleration Sensor

I have had my ABS light on since I bought my rig in June of last year, I was finally able to figure out how to pull the code and I get code 43 from the FSM; 43 (DI–205) Malfunction in deceleration sensor Deceleration sensor Wire harness for deceleration sensor circuit Anyone ever...

forum.ih8mud.com

Not sure these are correct but seems like they are:

DTC 43 is generic ABS malfunction
DTC 46 is master cylinder pressure
DTC 47 ?? not sure

https://st.club-lexus.ru/attach/u/56e30554.pdf

 

[Grond]

Brake system code

2004 GX470, 133k miles; on rare occasions, I get ABS, VSV TRAC and VSV OFF lights on. They typically go off by themselves after a little while, in the same drive cycle. Gas cap pretty new, just went through Louisiana testing without a hitch. Lexus sez there's a code C1246, skid control ECU...

forum.ih8mud.com

I have fixed a few ECUs that did not appear to have a bad resonator, ohmed out ok/worked fine in my LC. But after replacing and sending back appeared to fix the issue. Its definitely more cost effective than replacing a master cylinder.

ABS Code 43 - Deceleration Sensor

I have had my ABS light on since I bought my rig in June of last year, I was finally able to figure out how to pull the code and I get code 43 from the FSM; 43 (DI–205) Malfunction in deceleration sensor Deceleration sensor Wire harness for deceleration sensor circuit Anyone ever...

forum.ih8mud.com

Not sure these are correct but seems like they are:

DTC 43 is generic ABS malfunction
DTC 46 is master cylinder pressure
DTC 47 ?? not sure

https://st.club-lexus.ru/attach/u/56e30554.pdf

View attachment 3260177

Appreciate the help, I'll try and look further into these codes tomorrow. In the meantime I turned the truck on and pumped the brakes a bunch to build up brake pressure, since I was reading a pressure code. The buzzer went off, and now the ABS and VSC codes flash constantly, with no pattern. The A-Trac still goes off when I slightly try to accelerate even a little. Guess I broke it more.