yyymmm31

Symptom: The dash instrument display panel shows a yellow “!” light with the white warning message: “Brake Malfunction” or “Check VSC System” or “Check Brake System”, “Stop the vehicle immediately in a safe Place. Call a dealer”. The brake pedal feels hard and stiff. The photo below shows the actual warning messages (photo posted by CL Member Sleeper416).




Cause of the symptom: This is a common problem related to LS460 brake system. It could be triggered by any bad brake component, such as a water soaked brake sensor wire, a broken brake fluid tube, a broken brake caliper seal, or even worse, a bad brake actuator. In my case, it was triggered by an accidental operational error on my part. Last Sunday, I performed a full brake fluid bleeding procedure with Techstream on my 2008 LS460. When I was bleeding the third brake caliper (the rear right brake), my car battery died (lesson learned here). At this point, the brake actuator solenoid for the rear right brake caliper was still open. I removed the dead battery from my LS460 and put in a good one from another car. When I pressed the start button, the dash display panel showed the above error message. I was able to start my car, but the brake pedal felt hard and stiff.

Solution: Use Techstream to perform the following two procedures. Please note that this solution is only good for clearing the warning message when you brake system hardware is good. If you have a bad brake part (e.g., a bad actuator or broken brake tube), after your have cleared the warning message, it will come back soon. You'll need to replace the bad brake part first and then do a brake bleed procedure to clear the warning message, which is not more difficult but is a different process. I will post another tutorial for bleeding LS460 brake system when I have some time.

1) Reset Memory, and
2) Linear Valve Offset Calibration

Steps of performing these two procedures:

1. Connect Techstream to the OBDII port under the dash.



2. Select “ABS/VSC/TRAC” menu and double click it (or click the arrow at the right bottom of the screen).




3. Select “Utility” button on the left of the screen and double click “Reset Memory” menu (or click the arrow at the right bottom of the screen).



4. Click “Next” on the screen below.



5. Click “Next” on the screen to confirm resetting memory.



6. When the reset memory procedure is completed, click “Exit” to go back to the Utility Selection Menu shown below. Select “ECB Utility” and double click it to go to ECB Utility menu.



7. On the ECB Utility Menu, select “Linear Valve Offset”, and click “Next”.



8. Click “Next” on the subsequent two screens to confirm the linear valve offset procedure. Then, the final confirmation screen shows up. Click “Next” to begin the linear valve offset.






9. The linear valve offset procedure runs for 120 seconds. During this process, DO NOT press the brake pedal. When the linear valve offset procedure is completed, press “Exit”. Then, go to the “Trouble Codes” menu. There should be no error codes. If there are error codes, repeat the reset memory and linear valve offset procedures. When there are no error codes in the “Trouble Codes” menu, exit Techstream. Start the engine and the “Brake Malfunction”, “Check Brake System”, “Check VSC System” error message should disappear from the dash display panel. Test-drive the car to make sure that the brake system functions normally. Congratulations. You have successfully restored the brake system.
Other DIY Instructions:

• If your battery died when you were in the middle of performing the "linear solenoid valve offset" procedure, you would have two new brake trouble codes: C1256 (accumulator low pressure) and C1345 (Linear Solenoid Valve Offset Undone). Go to Posting #98 of this thread for the instruction to clear Codes C1256 and C1345.
• DIY Rebuilding LS460 Brake Calipers https://www.clublexus.com/forums/ls-...-calipers.html.
• Instruction to bleed the brake actuator, if you want to purge air out of the brake actuator assembly, or when you replace the brake actuator, of when your brake actuator is making noises, see the PDF file in Posting #7 of this thread: https://www.clublexus.com/forums/ls-...l#post10762895
• DIY Replacing TPMS Sensors - 2007-2009 LS460/LS600: https://www.clublexus.com/forums/ls-...460-ls600.html
• DIY Replacing Engine Mounts (without dropping the subframe) https://www.clublexus.com/forums/ls-...l#post11112759
• DIY Cleaning up "Strawberry Milkshake" Transmission Fluid Crossed into Cooling System https://www.clublexus.com/forums/ls-...ng-system.html

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UZ214

very nice this needs to be a sticky- thank you for sharing!

213374U

Very cool! Thanks for sharing

yyymmm31

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UZ214 and 213374U, thank you for your encouraging comments. The “Brake Malfunction, Check VSC System, and Check Brake System” warning signs are common dash error messages that early model year LS460 owners (i.e., 2007-2013) may experience. These error messages could be triggered by a number of brake related issues, such as a damp brake sensor or a small accidental mistake that a DIYer makes while working on the brake system. Because the warning message says "stop the vehicle immediately" and "call a dealer", most LS460 owners would panic and have their cars towed to a dealer upon seeing these warning messages, while not realizing that a few minutes' of a DIY procedure could solve the problem. I suspect that many small indy shops that are not familiar with LS460's electronic braking system would unnecessarily replace the good brake actuator as a solution, causing LS460 owners hundreds of dollars in repair bills. I hope that this tutorial will offer LS460 owners a DIY solution to resolve this common brake issue on their own. At least, before having their cars towed to a dealer or before having their brake actuator replaced, spend a few minutes and try this simple DIY process to save time (and money) if possible.
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joeccl

I have got similar issue after I mistakenly ran Test Mode with Techstream on my perfectly running LS460 (no error sign). I tried your instruction and unable to get back to normal. I created another thread and hope to gather advice from you guys if anything I try do next:

https://www.clublexus.com/forums/ls-...l#post10256990

Any comment is appreciated. Thank you.

yyymmm31

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Which model year is your LS460 (your profile shows that you have a LS430), and which version is your Techstream? Is P1345 the only trouble code shown in the Curr/Conf column of your Techstream trouble code screen?
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joeccl

yyymmm31

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Personally, I'm not a big fan of Techstream version 12 purchased on eBay or from other non-official channels. I have mixed results with Version 12 Techstream. I prefer Versions 10 or 13 because they tend to be more stable and reliable. If you can, get a copy of either Version 10 or 13 Techstream (unofficial version). Nonetheless, do the following:
1. Ensure that your car battery is fully charged;
2. Disconnect the negative terminal from your car's battery for 30 minutes and reconnect it (to ensure a full restart of the car's electronic system);
3. Turn the ignition to ON position without pressing the brake and wait for 4 to 5 minutes for the electric system to finish the restart and then connect Techstream to the car and (very important) select the right production year and month of your car (check the label on the driver's door to have the production year and month of your car);
4. Select the intended location of your car (e.g., Asia, HK, etc; if you imported your car from the US or another country, select the appropriate country/region location);
5. Select “ABS/VSC/TRAC” on Techstream;
6. Go to "Trouble Code"
7. Clear P1345 Error Code (you may save the error code to a file for future reference before clearing the code);
8. Go back to the "ABS/VSC/TRAC" screen;
9. Select “Utility” ;
10. Click "Reset Memory" ;
11. Back to the "Utility" screen and select "ECB Utility"
12. Select “Linear Valve Offset" and complete it;
13. Go back to the "Trouble Code" screen;
14. There should be no more P1345 code or any other brake related code;
15. Exit to Techstream's main menu and properly exit and disconnect Techstream;
16. Your brake system should be stored;
NOTE: This solution works only when there are no hardware issues on your brake system (i.e., contingent on your statement that there were no brake problems before you did "Test Mode" with Techstream).
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joeccl

Thank you very much for your detailed explanation.

I followed most steps you mentioned with the exception the following:
1) fully charge battery (only 12.6V max)
2) disconnect battery for 30 mins
3) wait for 4 to 5 minutes for finish restart
4) Techstream location (mine don't have Asia HK, only Japan/NorthAmerica/Europe/Other, so I selected Others [but I also tried all different countries after failure])
5) Techstream is not version 13. But a dealer's computer (some kind of portable Toyota machine) also failed the same way.

The learning process failed at around 20 sec left (out of total 120 sec). According to repair manual if P1345 code still exist after Linear Solenoid Valve Offset learning then I have to replace the ABS/brake Actuator, which is very expensive. I wonder if it is possible that my Actuator is actually working normal but unable to learn? I suspect if the learning data exist that it will function normally.

yyymmm31

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It looks that the error code was not cleared before the Linear Valve Offset procedure was run. Linear Value Offset can't be performed successfully if you have brake system error codes or when the memory was not reset (cleared). The reason I suggested disconnecting the battery is that it will give you a fresh start. Car ECU's are no different from computers. On many occasions, a simple power-off off will clear "dirty" memory butters and will allow you to write new config's into ECU's. It is like when you are stuck with an old set of IP configuration on your PC and won't be able to connect to a new WIFI access point. The easiest way to solve the WIFI problem in this situation is to restart the PC (of course if you are a computer guy, you could use ipconfig to clear old IP settings and renew lease, etc. without restarting the PC). In most cases, working on LS460 electronics is like working on a computer. If your brake actuator was good before you ran the Test Mode, I don't believe that your actuator is bad because you ran Test Mode. It may just have bad configs, and you need to clear (erase) the bad configs and write in the correct configs. I suggest that you (1) disconnect the battery for 30 minutes, (2) clear any brake related error code, (3) reset memory, and (double check that there are indeed no error codes) run the Linear Value Offset.
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joeccl

For "clearing the error codes" you mentioned, do you mean "Trouble Code-->Erase" or "Reset Memeory"? I am unable to clear the error code at all even I used the Erase function. It seems clear the code but immediately scan again, then the same code displayed.

I will try the disconnect battery as you mentioned.

yyymmm31

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Yes, disconnect the battery for 30 minutes (enough time for a natural system reset and restart). Additionally, if your car was originally sold in HK (right-side steering wheel), when you connect Techstream, select Japan or Australia as the region/country. Please also select the correct manufacture date of your car (very important) by checking your driver's door label. You need to clear brake error code in Trouble Code first, and then do a Reset Memory. Remember, you can't have a successful Linear Valve Offset unless you have cleared brake error codes and have reset the memory (e.g., purging out any memorized bad brake configurations from memory).
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joeccl

I tried to disconnect the battery for 30 minutes. I am unable to clear the error code P1345 in Trouble Code no matter how many times I did it. Maybe that is why I cannot successful Linear Valve Offset. Are there any other ways I can try to clear the code?

yyymmm31

[QUOTE=joeccl;10258550]I tried to disconnect the battery for 30 minutes. I am unable to clear the error code P1345 in Trouble Code no matter how many times I did it. Maybe that is why I cannot successful Linear Valve Offset. Are there any other ways I can try to clear the code?
/QUOTE]
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You screen shot shows C1345, not P1345. Error code C1345 can often be cleared by running Test Mode procedure. You may run Test Code procedure to clear C1345 code. During the Test Mode, your ABS warning light blinks and the VSC test mode message is displayed on your dash. Don't panic and terminate Test Mode by unplugging Techstream. Be patient and wait for Techstream to complete the Test Mode procedure. After the Test Mode is completed, go to Trouble Codes and C1345 code should be cleared. Once again, if you can, use Techstream Version 10 or 13, which in my opinion are more reliable and consistent than Version 12.
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joeccl

[QUOTE=yyymmm31;10258638]Thanks for reminding, it is actually C1345. Sorry for the confusion.

I tried Test Code many times before but it doesn't seems to be able to complete (The two lights stay on instead of "flashing very fast"). I will try again with 30 mins power off to see the difference. Do you think I need to run Reset Memory and Linear Value Offset after Test Mode?