ABS VSC TRAC saga continues...thoughts? (2 Viewers)

Joined
Mar 2, 2021
Messages
28
Location
Reno, NV
Hello all -

I bought 07 lx470 with 112k miles last year and after about 2k miles I noticed the ABS light would come on sometimes, if I were to hard brake it might go off, sometimes that didn't do anything. It would come on and off intermittently and then went away for a while. Earlier this year, the ABS light started to stay on and then the VSC TRAC lights were coming on and staying on.

Mind you I have had no issues with the car. There was a viper alarm already installed and sometimes that will give a startup beep but no buzzing sounds, no CEL, no difficulty with brakes. I installed the px6 radio but I can't see how that is affecting things. Did an AHC flush and that system is working great. The car steers well.

Oddly, now that it's cooling down at night here, I noticed the other day that the lights had all gone off (except for tire pressure light but i know that TPMS #2 is bad and I need that replaced) but then through the day those three lights will come back on. Has anyone had temperature sensitive lights like this??

I plugged into Autel reader and had a slew of codes:
c1223 - abs control system fault
c1246 - master cylinder pressure sensor
c1336 - ZPC not performed, although I have tried to jump this with paperclips and nothing seemed to change
c0371 - yaw rate sensor

c1275-c1278 speed sensor codes
c1282 - center diff lock position switch (???)

I've replaced the rear brakes/rotors and that went well and plan to do the front brakes with the speed sensors.

I guess my question is...wtf is going on? With all the codes being thrown but no obvious physical manifestations, it seems like an issue with some central control device, maybe ECU?

The odd part is the weather being colder and the codes going away and coming back, which I can't really explain.

Any ideas on more in-depth diagnostics?

TYIA

WR
 
Joined
Mar 14, 2003
Messages
16,104
Location
Gig Harbor WA
Any of your shifter lights out on the dash...especially the P Park light?

Had a sorta( very) similar issue on my 2000....turns out the P bulb burned out....and set off dash lights and codes. I think I had all the same codes on Snap On scanner I used as you do...everything from $300...to $3000....but it was a $3 bulb...which the scanner can't help with...it says toss $$$$$$...lol

The prior year I replaced the burned out bulbs D, 2,etc but I somehow was short 1...so because the P was still good I left it in.

Thankfully a year latter my ADHD brain had a flashback.... the P light had just went out....and this issue just popped up.

If I recall the warning lights would go out if shut it down..but then come back after a certain speed or something odd like that.

For some reason toyota uses the P bulb as part of its sensors or something...and when dead tr8ggers the warning lights

Been a year or more...and no issues.
 
Joined
Mar 2, 2021
Messages
28
Location
Reno, NV
Dash lights are working well. All the bulbs seem to be in working order.

We shall see over the next 1-2 weeks as it's getting colder, if the lights stay off when it's cold...then I am seriously confused!
 
Joined
Oct 11, 2010
Messages
573
Location
Calgary, Canada
I would test the CDL sensor first, then the speed sensors (the ones throwing the codes).
If all test good I would look into the brake booster, it might be early signs of failure. The brake ECU is very rare to fail but also quite cheap (used) to replaced if you wish to rule that out.
Is the brake booster acting up? how often does it cycle?
I think I got a C1223 or a C1225 when mine was going out. About 100k miles when that happened.
 
Joined
Feb 9, 2020
Messages
5
Location
Virginia
I have a 2002 with the VSC TRAC and VSC OFF lights on. My independent garage said that they are not able to communicate with the YAW sensor, and say it needs to be replaced. I have attempted to clear the previous memory and calibrate the yaw sensor using a jumper in the dlc1 as described on another thread Saved myself $100 fee - https://forum.ih8mud.com/threads/saved-myself-100-fee.258484/post-3996531. I did not receive the light responses that would have indicated success, though I did get a long beep when I took the last step, "clear diagnostic codes". But my VSC TRAC and VSC OFF lights remain on. I'm not sure if this confirms what my garage reports or not. I was thinking to at least take a look at the yaw sensor and see if there's anything obvious that's wrong. I'm not finding any posts about this. Can anyone direct me to how to get at and potentially test the yaw sensor before springing $900 for parts and labor to replace it? I don't see posts that indicate this is a common failure part. I know the garage would warranty the fix and stand by their solution, but I'm wondering if I could get a better sense of it in my home garage.
 
Joined
Mar 2, 2021
Messages
28
Location
Reno, NV
Truly the saga continues on my side.

Updated repairs: I changed brakes and rotors all around, brake fluid flush and while there I repacked bearings and replaced the front ABS sensors. They were brittle and dirty, cleared the sensor port well. Did plugs, tcase, trans fluid flush as well since I'm at 120k miles.

The battery has died a couple times and it's driving me crazy. I checked the volts and 12.5V at rest and then on start up jumps to 14.2V so alternator is doing fine. I suspect I have a parasitic draw, but I haven't had time to check this and not sure how that is affected the rest of the car, specifically the ABS/VSC.

Oddly, the ABS/VSC lights go on and off, they seem to be off earlier in the day and before things 'warm up' although I can't explain that. I was parked on a slight upwards incline and when I turned car back on the lights were off! Then came back on, stayed off later on for about 1 day and then back on last night.

The infrequent nature of this makes me think it's more mechanical, rather than the ECU going bad. I went to my mechanic and they pulled only one code, the steering angle sensor apparently is bad. The car does list a little to the right and the steering wheel appears slightly off. I was quoted $1000 for the angle sensor replacement.

I am just going through the checklist and I am truly stumped.

Is the yaw sensor somehow related to the steering angle? I believe the FSM shows the yaw sensor is under the center console.
 
Joined
Mar 2, 2021
Messages
28
Location
Reno, NV
I've always known batteries to be 12.5-12.6V at rest
 

jerryb

Supporting Vendor
Joined
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2,773
Location
pensacola fl.
ok. Does it maintain 12.5 over a period of days. I just ask because I replace them anytime I get a reading under 12.6 after charging them and letting them sit for a day or two.
They've always tested bad to.

but if you say your battery has died a few times, at what voltage do you find the battery at before you jump it?

charge it disconnected from the car and let it rest a day and see if it maintains 12.6. Not saying there isn't a draw but if it doesn't maintain 12.6 off the car or disconnected at the car then it isn't good and needs replacement.


this one says you have to reset both sensors in order to do a zero point recal.

1670152212022.png
 
Joined
Nov 4, 2007
Messages
12,061
Location
Colorado
Hello all -

I bought 07 lx470 with 112k miles last year and after about 2k miles I noticed the ABS light would come on sometimes, if I were to hard brake it might go off, sometimes that didn't do anything. It would come on and off intermittently and then went away for a while. Earlier this year, the ABS light started to stay on and then the VSC TRAC lights were coming on and staying on.

Mind you I have had no issues with the car. There was a viper alarm already installed and sometimes that will give a startup beep but no buzzing sounds, no CEL, no difficulty with brakes. I installed the px6 radio but I can't see how that is affecting things. Did an AHC flush and that system is working great. The car steers well.

Oddly, now that it's cooling down at night here, I noticed the other day that the lights had all gone off (except for tire pressure light but i know that TPMS #2 is bad and I need that replaced) but then through the day those three lights will come back on. Has anyone had temperature sensitive lights like this??

I plugged into Autel reader and had a slew of codes:
c1223 - abs control system fault
c1246 - master cylinder pressure sensor
c1336 - ZPC not performed, although I have tried to jump this with paperclips and nothing seemed to change
c0371 - yaw rate sensor

c1275-c1278 speed sensor codes
c1282 - center diff lock position switch (???)

I've replaced the rear brakes/rotors and that went well and plan to do the front brakes with the speed sensors.

I guess my question is...wtf is going on? With all the codes being thrown but no obvious physical manifestations, it seems like an issue with some central control device, maybe ECU?

The odd part is the weather being colder and the codes going away and coming back, which I can't really explain.

Any ideas on more in-depth diagnostics?

TYIA

WR
Truly the saga continues on my side.

Updated repairs: I changed brakes and rotors all around, brake fluid flush and while there I repacked bearings and replaced the front ABS sensors. They were brittle and dirty, cleared the sensor port well. Did plugs, tcase, trans fluid flush as well since I'm at 120k miles.

The battery has died a couple times and it's driving me crazy. I checked the volts and 12.5V at rest and then on start up jumps to 14.2V so alternator is doing fine. I suspect I have a parasitic draw, but I haven't had time to check this and not sure how that is affected the rest of the car, specifically the ABS/VSC.

Oddly, the ABS/VSC lights go on and off, they seem to be off earlier in the day and before things 'warm up' although I can't explain that. I was parked on a slight upwards incline and when I turned car back on the lights were off! Then came back on, stayed off later on for about 1 day and then back on last night.

The infrequent nature of this makes me think it's more mechanical, rather than the ECU going bad. I went to my mechanic and they pulled only one code, the steering angle sensor apparently is bad. The car does list a little to the right and the steering wheel appears slightly off. I was quoted $1000 for the angle sensor replacement.

I am just going through the checklist and I am truly stumped.

Is the yaw sensor somehow related to the steering angle? I believe the FSM shows the yaw sensor is under the center console.

You could likely have more than one issue.

These things, should not be happening in a low mile, rust free rig, no accidents, with factory windshield and drains working (no water entry).
It, suggest accident, rodents, water leakage into junction boxes and or service mess ups. Also a big clue you: Electrical aftermarket add-ins.

VRGS snap ring recall was 03- 07LX470. Sometimes they mess doing the repair. Making a mess in tech stream as they re-calibrate.

Undone Zero point, is often, procedure not completed after undoing with paper clip.

I'd also be looking at: Brake master reservoir level & fluid condition and booster control wire contact points (inside boots) as a first glance walk around inspection.

ABS lights are very common if any issue in any system.

Temperature drop: All good cold, then warm up dash lights. May be clue; In that resistance in electrical wiring and components is low (best). Heat = high resistance which inhibited current (bad).

Battery issues can be loose contact at battery, oxidation between post and camp and or something between post & clamp. I use only white lithium grease applied to clean post, and never that "red spray" junk. Toyota recommend nothing be used, not even grease. Easy test for inhibited contact between post & clamp: Check voltage at post, than at points away from post (like clamps). If you see voltage drop, contact is inhibited between post & clamp. Not fully changing battery every time and keeping fully charged at all times, will damage battery (sulfate).

Key off, Draw on battery:
  1. OM states turn headlights off. In auto while parked, more than ~week will drain battery.
  2. One of the most common draws on battery, is drop down or headrest DVD players. These aren't actually factory installed. They're install pre-first sell in the USA. Pull the fuse!
  3. After market add in. Here we see so many issues, depending on who instated and what.

But here's where the waters can get very "muddy" After market electrical adds.
Any alarms, dash lights, DTC, etc. That started after aftermarket stuff install. Especially that involved any electrical work (tap into elect, under-dash, fuse, junction, etc.) or even touching electrical contact points CPU's, etc.. Is highly suspect! It is where I'd start!


I have a 2002 with the VSC TRAC and VSC OFF lights on. My independent garage said that they are not able to communicate with the YAW sensor, and say it needs to be replaced. I have attempted to clear the previous memory and calibrate the yaw sensor using a jumper in the dlc1 as described on another thread Saved myself $100 fee - https://forum.ih8mud.com/threads/saved-myself-100-fee.258484/post-3996531. I did not receive the light responses that would have indicated success, though I did get a long beep when I took the last step, "clear diagnostic codes". But my VSC TRAC and VSC OFF lights remain on. I'm not sure if this confirms what my garage reports or not. I was thinking to at least take a look at the yaw sensor and see if there's anything obvious that's wrong. I'm not finding any posts about this. Can anyone direct me to how to get at and potentially test the yaw sensor before springing $900 for parts and labor to replace it? I don't see posts that indicate this is a common failure part. I know the garage would warranty the fix and stand by their solution, but I'm wondering if I could get a better sense of it in my home garage.

Undone Zero point, is often procedure not completed after undoing with paper clip. Finish procedure with tech stream. Or take to a good (not all are) Toyota/Lexus Dealership for diagnostic & zero point cal. Or get Tech stream hook up yourself.

Sorry but most INDY, haven't a clue!
 
Joined
Aug 11, 2013
Messages
112
Check your abs brake module/ master cylinder. You could be getting an alarm is your pressure switches in the brake master to control the booster pump are bad. They tend to malfunction at low temps.
Try this: after you turn off the engine and remove your key, pump the brakes 5-10 times to reduce the pressure. That will depressurize the brake system and leave your high pressure switch off. This switch gets sticky at low temps. If the booster pump runs for > 5 min, it will turn alarms on. The high pressure switch turns the pump off. Low pressure turns it on.

2001 LX 470 ABS replacement? - https://forum.ih8mud.com/threads/2001-lx-470-abs-replacement.1259359/post-14003621
 
Joined
May 26, 2022
Messages
148
Location
San Antonio
Do you by chance have poly steering rack bushings installed? I recall a thread that mentioned aftermarket poly bushing messing with the VSC system.
 
Joined
Feb 9, 2020
Messages
5
Location
Virginia
Wow, really? I did install these Whiteline bushings not long before this whole mess started. The lights came on when my son braked hard on an exit, turning to the right.

Can you point me toward other information about this?
 

jLB

Another one followed me home. Can we keep it?
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Joined
Dec 2, 2014
Messages
3,458
Do you by chance have poly steering rack bushings installed? I recall a thread that mentioned aftermarket poly bushing messing with the VSC system.
Curious. I’ve got polyurethane steering rack bushings on all three of ours, (only two have VSC) without any VSC issues.

I do recall having a VSC issue, after replacing my son’s steering rack, prior to recalibrating the system with Techstream though.
 
Joined
Nov 4, 2007
Messages
12,061
Location
Colorado
I really can't see poly rack bushing, resulting in ABS, VSC or VGRS issue. Just the opposite actually, as they firm steering rack movement. Which results in less side to side movement. Note: OEM rack rubber bushing, are designed to allow for (a softer) side to side movement.

You can get ABS, VSC, TRAC lights from, loose front end components. Like bad rack mounting bushing (sloppy), TRE, ball joint, loose wheel bearings, even to little pressure in AHC and or bad shocks (bouncy). These things, all could cause wheel speed sensors to get a signal, that one or more tires rotating at different speed than others.
 
Last edited:
Joined
Feb 9, 2020
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5
Location
Virginia
Update: lights are off. I took my rig to a local LC specialist. Initially they were unable to clear codes, confirming what I and a previous independent reported. They started checking voltage, and apparently disconnected a thing or two, driver's side under dash. Voltage was normal. Upon reconnecting and starting car, the lights were out. Very inconclusive, but their best guess is there was a bad connection that was impeding proper voltage flow through the system.
 
Joined
Nov 4, 2007
Messages
12,061
Location
Colorado
Sounds like aftermarket wiring, which I hate seeing.

I spent 3 days removing a mile of wiring, from just one LX alone. Some was Dealership or Depot install mile one, other toys added later. Only thing I saved from that job, was battery tender wired in. Which was clear indication the toys and wiring, were drawing down battery key off!

I run into so many issue from hack wiring jobs.
 

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