My VSC light wont turn off

As a friendly little PriusChat reminder, based on the schematics I posted ....

Never, ever EVER touch pins 4 & 13 on the DLC/OBD port.

Ever

CORRECTED

Well, maybe not EVER, but you probably shouldn't. Touch the wrong pins, instead of entering the basic "blink code" diagnostic, you could fry something. Yes the shop manual warns about this, and for that reason prefers you use the proper diagnostic tester

 

I mean it, too

 

[Anybody know users at Toyota Nation? I can't speak for an '05 Tacoma, but I can state with certainty that touching together DLC/OBD port pins 4 & 13 on an '04 Prius and an '07 FJ would cause catastrophic damage] CORRECTED

CORRECTED

Pin 13/TC is used to access a basic blink code diagnostic feature. You must understand that the shop manual warns that touching the wrong pins on the DLC/OBD connector could cause damage/malfunction. The prefered method is to use the proper diagnostic tester

NOTE: Pin 13/TC can NOT command the brake boost pump, or the solenoid valves in the braking system. You must use the correct Toyota specific diagnostic tester. If you do not have proper training on the Prius braking system, you MUST take the car to the dealership. By default, just opening the rear bleeder screw will isolate that part of the braking system, increasing the odds of a crash

 

Ok snooped around some more regarding the DLC/OBD pins 4 (Ground) and pin 13 (Assumed power). The diagrams are crowded and hard to read. It did look like pin 13 was power, and I was wrong about that

Actually pin 13 is TC, which is used for the SRS diagnostic. There is a special service tool #09843-18040 that you use to activate the SRS diagnostic.

Note: I would never, ever recommend just using a wire. If you happen to touch the wrong pins, you still risk catastrophic damage

According to the service manual, this is the "quick" procedure to check for stored DTC's related to the SRS. The prefered method is still to use the dedicated tester

[Pin 13 has nothing whatsoever to do with the braking system.] CORRECTED

TC allows retrieval of basic ABS codes. It cannot command the boost pump, switch the solenoid valves, etc. The correct handheld tester is required to bleed the brakes

Photos follow

 

Pin 13, on the DLC/OBD connector, is called "TC" and is referenced to in the SRS section of the repair manual. This covers the airbags, airbag sensors, etc

 

The service manual *strongly* cautions about using the "blink" method. For example, a SST is required which is "goof proof." Just using a wire, they warn that shorting the wrong pins can cause "malfunction and damage." I bet!

This is a sample "blink code" for an airbag system error on a 2004 Prius

 

In the service manual this is the way to clear a stored airbag system DTC. The manual strongly cautions you to use the approved diagnostic tester

 

I just checked the SRS section of my 2007 FJ Cruiser service manual. The SRS diagnostics are almost exactly the same as for the 2004 Prius. That is, the DLC/OBD pin 4 (Ground) & 13 (TC) are used to activate a blink code

The FJ SRS section also strongly warns about potential damage to using the blink method. They require the same SST to "goof proof" shorting the two pins. The prefered method is to use the handheld tester or Panasonic ToughBook

The 2007 FJ Cruiser DLC/OBD port pin 13 (TC) will also work with basic ABS codes. It cannot clear manufacturer specific codes. It cannot command the electric boost pump

 

I have already covered the correct bleeding procedure in other posts

http://priuschat.com/forums/attachm...n-bleeding-prius-brake-bleeding-procedure.pdf

As you cannot command the solenoid valves to switch with a simple DLC/OBD port shorting procedure, you risk having no brakes at all, or at least not the proper bleed procedure on the part replaced. The solenoid valve will close and isolate that system

This is the Prius braking system

 

This is an example of one of the braking failure modes

 

Which brings up a pet peeve of mine: these diagrams and schematics are *way* too tiny for tired, middle aged eyes. I find them difficult to read, and if you zoom most of them, the resolution is too low to see anything but a blur

 

I keep thinking I see extra nodes in the schematic, but then it turns out to be floaters in my eyes.

Tom

 

You too? Seems once a person is +45, its all downhill health-wise

 

i understand the concern about power is resolved. DH's input is that there is very limited info you can retrieve from blink codes anyway. if you're that concerned with getting codes, are that averse to going to the dealership, and you need to resort to jumping pins, just get a used scantool. cheaper than screwing up which pins you jump.

auto zone can only get codes from the engine ecu, fwiw.

finally, NEVER EVER EVER attempt prius brake work in a DIY fashion. EVER.

 

The Voice of Reason. Thank you

 

I feel that I've fallen victim to having seen this thread only too late.

Given the large number of other threads suggesting it's easy to do brakes... no problem! I went ahead. (see post: how to replace disc brake pads and rotors)

Then I had the ABS issue, and unfortunately found the thread "how to reset abs light" which outlined how to use an SSD to connect #4 and #13 on the obd2. Again, it's unfortunate that I'm only coming across this thread after the unfortunate fact when I searched problems with doing so.

Now, I'm afraid that I've done significant damage. It won't start, just keeps trying to power up even if I repeatedly try to power it back down. Other weird symptoms too.

This may be to a point where the moderator should do *more* than just put a post up here and consider taking down those other threads or flagging them with pinned warning up top before too many folks do more damage.

By the way, I feel that I'm a responsible DIY'er having done my own brakes at least a dozen other times on other cars without issues.

 

Please do not post in multiple strings on the same issue. My response to your query can be found here:
How do you reset ABS light & yellow ((!)) ? | Page 2 | PriusChat

 

I was posting in this thread to potentially flag this issue to the mod (who acknowledged potential issues with the obd2 ssd above in this thread), and in the other more for tech conversation, though I realize they are very similar and will definitely take note of that. I'm a noob trying to understand the differences between three threads that seem very similar yet nuanced! Thank you, B

 

It's 2017 and I just learned about these posts from someone who was scared off by them from following a simple, documented procedure to get ABS/VSC/TRAC codes when a scantool isn't available.

As for needing to use the special service tool #09843-18040 instead of a wire ... it is a wire:



Yes, if you mess up your counting to find pins 4 and 13, you might cause an effect you don't intend (and it might involve lasting damage to something, but more likely will cause some comm error codes to be logged and more lights to come on, and be embarrassing).

If you get behind the wheel and drive into a tree or a pedestrian, you might cause a fatality. You trust yourself not to do that, every time you drive a car. To pull your diagnostic codes, you need to trust yourself to count to 4 and 13 (or match up the picture, or, even better, both).

It's just not that hard.

-Chap