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CLEAR DTC (When not Using Intelligent Tester)

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ivanbg, Oct 2, 2009.

  1. ivanbg

    ivanbg Junior Member

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    CLEAR TROUBLE CODES (DTC) (When not Using Intelligent Tester)

    [FONT=&quot]

    CLEAR DTC (When not Using Intelligent Tester)[/FONT]

    [FONT=&quot](a) Using a jumper wire, connect terminals TC and CG of the[/FONT]
    [FONT=&quot]DLC3(OBD2).[/FONT]
    [FONT=&quot] (b) Turn the power switch ON (READY).[/FONT]
    [FONT=&quot](c) Clear the DTCs (Trouble Codes) stored in the ECU (Electrical Control Unit) by depressing[/FONT]
    [FONT=&quot]the brake pedal 8 times or more within 5 seconds.[/FONT]
    [FONT=&quot](d) Check that the warning light indicates a normal[/FONT]
    [FONT=&quot]system code.[/FONT]
    [FONT=&quot](e) Remove SST( jumper wire).[/FONT]
    [FONT=&quot]HINT:[/FONT]
    [FONT=&quot]Clearing the DTCs cannot be performed by[/FONT]
    [FONT=&quot]removing the cable from the negative (-) battery[/FONT]
    [FONT=&quot]terminal or the ECU-IG fuse.[/FONT]

    [FONT=&quot]END OF CHECK/CLEAR[/FONT]
    [FONT=&quot](a) Turn the power switch ON (READY).[/FONT]
    [FONT=&quot](b) Check that the Brake Control warning light, ABS[/FONT]
    [FONT=&quot]warning light and VSC warning light go off within[/FONT]
    [FONT=&quot]approximately 3 seconds.[/FONT]
    [FONT=&quot]
    [/FONT]
     

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  2. ivanbg

    ivanbg Junior Member

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    I apologize if someone has already posted how to do this. I did a quick search but could not find how to rest the abs light.
    When I tried to bleed the brakes and my abs light came on. I tried to use the scangauge but it did not find any trouble codes. After a couple of hours of reading the factory service manual I came upon this. It was well hidden in the text. The abs system did not reset until I pumped the brakes as mentioned above. Next time what I would do is pull the power from the 12volt battery to keep the abs system from activation while doing the bleed/brake flush.

    If any one wants to ask; No I am not going to take it to the dealer with the special[FONT=&quot] Intelligent Tester [/FONT]to do a break flush.
     
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  3. jayman

    jayman Senior Member

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    So, how could you have possibly flushed the brake system without having the dealer scantool to command the pump and solenoid valves?

    Your method of clearing the DTC will work for most stored codes. But will not command the solenoid valves to open properly to flush/bleed the brakes

    The correct procedure is in this thread

    http://priuschat.com/forums/gen-ii-...em-rear-brakes-no-pressure-when-bleeding.html

    I hope you actually do have working friction brakes
     
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  4. ivanbg

    ivanbg Junior Member

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    Actually I just wanted to get some fresh fluid in the system. I bleed them until it stopped in the rear and the front a few times. Then the abs light came on an the rear bakes were useless because these valves triggered and stop the flow. I looked at the blue prints and it looks like if you pull the battery first then there won't be any way to for the car to send a voltage to the solenoid to get it to close and keep it there.

    Also when the battery of fuse is pulled the abs system would be shut off like it usually is on most regular cars when they are not running.
     
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  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Fascinating. How much old fluid did you get out of the system?
     
  6. jayman

    jayman Senior Member

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    The point is, if it were that easy the dealership wouldn't have the tech hook up the Panasonic Toughbook and go through the documented bleed procedure. That procedure commands the pump to run at certain times, and commands only certain solenoid valves to open or close

    The system cannot sense air in the lines, unless it triggers a pressure sensor. Once fluid stopped coming out, and you cleared the DTC, under normal braking there is no way to determine if the friction brakes will work properly
     
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  7. ivanbg

    ivanbg Junior Member

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    No one said it was going to be easy to trick the system. But it is ridicules that you have to go to the dealership to get a simple job done to the car. I am hoping that eventually the aftermarket market will be able to make an affordable product that hooks up to a laptop and has software that is compatible with the Prius.

    Clearing the codes should open the valves back up. Unless if you have introduced air in the brake system or messed up anything else, the car should be back to the way it was. With out clearing the codes, you cannot tell the car the problem was fixed and that if car release the shut off valve to the rear brakes.

    I think that you totally missed the point of this post. I am not saying the resetting the car fixes problems. What I am saying is that if you were messing with the car and it triggered an error ( like me opening to rear valves and the car thinks that there is a leak, and shuts off the flow) this is how to reset this lights on the dash. Unless if there was air introduced in the brake system by the person working on the car everything should be back to normal.
     
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  8. ivanbg

    ivanbg Junior Member

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    I got 10 oz out of each side. I used a hose that made a loop down at the bottom, so if the car was to pull in air would not go in. I used the hose and jar from the mighty vac kit. I used to vac to remove the fluid in the tank and top it off completely with new brake fluid.
     
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  9. jayman

    jayman Senior Member

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    Yes, that is my hope too. For example, if you have a GM product, you can *easily* purchase aftermarket software, if you wish going to OTC and spending top dollar, to be able to do EVERYTHING. In this regard, Toyota is NOT as user friendly as the rest

    We may have to wait a long time for compatible software. The embedded RTOS in the Prius is one I program with, and is used in the defense industry. A NDA prevents me from disclosing the name of the company, but I can drop a hint that almost the same RTOS is in the F/16, F/18, and F/22

    The Prius community has tried very hard to educate owners and mild DIY types, but a certain amount of caution must be exercised. I'm sure you'll admit it would be very easy to get the Prius brake bleed wrong, and end up with no brakes at all.

    Toyota does appear to learn from their past experiments. My FJ Cruiser also has electric assist brakes. Unlike the Prius, the brake fluid flush/bleed is almost the same as for a conventional vehicle

    Like the Prius, when you bleed the rear brakes on an FJ, you do NOT pump the brake pedal. Ig on, you maintain constant force, and the brake pedal does NOT move at all. My helper was very surprised at this, he asked if I had started yet, and I told him I was already done

    With the front brakes, the pedal DOES sink when you open the bleed screw. And, like the Prius, when you're done there is a brake warning that is cleared using the poorly-documented DLC pin 4-13, and the brake pedal "dance"

    Although I believe that almost anybody who has bled brakes on other vehicles can comfortably bleed the brakes on an FJ Cruiser (But the brake warning light will be on after they are done), IMHO bleeding the Prius brakes is different enough, and challenging enough, that it is beyond the skill level of an average DIY
     
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  10. ivanbg

    ivanbg Junior Member

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    I admit that the prius is not a car for those that do not feel comfortable working on cars and is there first or second time doing mechanical work.
     
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  11. ivanbg

    ivanbg Junior Member

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    Here are some pictures of how the screen looks like when there is a problem and you follow the procedure written up top.
     

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  12. jayman

    jayman Senior Member

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    Yep, screen looks familiar
     
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