How can I read brake codes on my Gen 1 and other brake questions

1) 4 main options:

1. Auto parts store
2. Bluetooth OBD reader ($12) and Torque Pro for Android ($6) - can install Prius specific codes to read much of the Hybrid Control and battery data (OMFG WIN!).
3. Wifi OBD reader ($20) and OBDfusion for iphone ($10) - meh
4. MiniVCI ($30) and Win-32bit laptop you provide - same diagnostics as Dealer

2) Not sure.

Good luck!

Steve

 

Absolutely ... paper clip, short piece of plain wire, whatever's handy. A quick search in this forum or elsewhere should easily get you a diagram of the DLC3 connector that will point out which pins Tc and CG are. Just be sure you don't go poking the wire into the wrong holes, take two or three good looks at the diagram and the connector under your dash.

When you turn on the ignition most of the computers will be in diagnostic mode and they will flash out two digit codes on different dash lights (that is, you count one group of blinks, then the next group after a little pause, to get your two digits). Multiple codes can be blinked out, with slightly longer pauses between them. You know you've seen them all when the first one you wrote down comes around again. Count the BRAKE light to get brake codes. You might see codes from other computers too. Any light that just does a steady fast blink means that computer hasn't got any news for you.

Best way to find out what the codes mean is the manual ... techinfo.toyota.com. It's behind a $15 paywall good for two days of access, pays for itself N times over in the money you save not making wild guesses about your car.

What you want will not be little one-liner fortune cookie messages for the codes, but the code table in the manual where each code sends you off to a page or six that cover exactly what you need to find out next.

-Chap

 

In addition to Chap's great post above, I'll add this.

You remembered incorrectly or misunderstood.

Mini VCI will read brake codes and everything else to do with your hybrid (or any other Scion, Toyota or Lexus). It gives you the same level of diagnostic ability as a Toyota service center.

You can install it on your Mac too, as long as you have a BootCamp Win XP/Win 7 (32-bit) partition setup. You could also use a 3rd party VM such as VMWare or Parallels etc. Set up an individual diagnostic only image for Mini VCI with no network connectivity, for reasons that will be explained as you look more into it.

Another option that has recently come up mentioned by another member here, EdtheFox5, is VXDIAG:

Hope that helps.

 

I have no personal experience, and although they claim it is compatible with all vehicles with OBD2 1997 onwards, the problem can be reading a particular manufacturer's proprietary codes. It probably will do a good job reading generic codes, but fall down reading proprietary codes.

Maybe a member who has one of these could give a run down of it.

 

So the thing is, OBD-II is a sort of lowest-common-denominator regulatory standard that says to all automakers "thou shalt have these certain parameters and these certain codes that can be read from your vehicle in these standard ways" and so OBD-II vehicles do have to have those parameters and those codes, and anything calling itself an OBD-II reader has to be able to read those. But nothing stops the manufacturer from having lots of other diagnostic information you could also read by connecting to the same diagnostic port, but that standard OBD-II readers won't have any clue about.

There are diagnostic-code ranges that the standards reserve for manufacturer definition, and the same with reserved ranges of data parameters, but it goes well beyond that. There are something like seven different computers in a Gen 1 Prius responsible for different things, most of which a standard OBD-II reader would have no reason to even know are there. The Gen 1 is extra funky because a bunch of them share the same communication port but using different communication parameters and bit rates so whenever your scan device connects at 10.4k "9141" it is guaranteed not to see the ones that talk 9.6k "14230", and vice versa.

It got a lot tidier after the CAN standard came along and was used in the Gen 2. It's funny how much of Gen 1 was kind of cobbled up starting with parts they had around, like the way the rear cupholder is obviously a mutant ashtray.

-Chap

 

Out of that list I can only find 2 valid Prius Codes:

• C1252 = Brake Booster Pump Motor on Time Abnormally Long
• C1256 = Accumulator Low Pressure

[EDIT]: I stand corrected, 1251 and C1214 are also valid. Obviously my reference list is incomplete, see Chap's post below. Thank you Chap

 

What on earth do you mean? C1251 is covered on pages DI-406 to 408, C1252 is DI-409 to 415, C1256 is on DI-424 to 429, and C1214 is on DI-386. (All page numbers from my 2001 manual, for Karen's 2003 pages may be different.)

I would disregard the C1214 for now. Complaining about control of hydraulic pressure is beside the point when there is no hydraulic pressure to control.

From the C1251 and C1252 we know the hydraulic boost pump motor isn't running. Whether that's a wiring problem, relay problem, or the motor itself (which is something of a PITA to replace) is the next order of business. The pages listed above (or, the equivalent pages in Karen's manual) give tests and procedures to figure that out.

The manual suggests some tests by applying battery voltage right at the connectors on the pump. While that's a very direct test, it's also kind of inconvenient because those connectors are about as buried as the pump itself is. If you can find where the HYDRO MTR relays are (that's easy) and which socket terminal is which (wiring diagram, also on techinfo) you can do some of the same tests while standing upright. You can also find where the pump monitor wires run back to the brake ECU, which is under the dash ... also a little inconvenient to get to, you have to stand on your head in front of the driver's seat).

Sort of by accident, there's another post around that describes the control and monitoring for that pump a little bit ... I was replying on a thread about whether on-board diagnostics made auto work harder or easier, but it just happens that pump was the exact example I used.

-Chap

 

Hello,

I have a 2010 Prius in Fiji islands and have encountered C1214 error.
Clearing the error gets the break working in electronic mode, but after an Engine stop the error pops up again.

I am told its a brake pump issue, but according to Prius Error codes, its to do with Brake rotor and master cylinder fix.

Has anyone come across the issue?

 

This is a thread in the first-generation Prius (2001 to 2003) forum, so you might get a better response in the Gen 3 forum for your question about a 2010.

That said, the C1214 code indicates that the brake controller was having trouble maintaining the target hydraulic pressure while you were braking. That can happen for a variety of reasons, including leaks, faulty valves, or even just uneven pressure because of a rotor that isn't flat. If you have just replaced pads, the code can be set the first time you use the brakes, just because the pads had to travel extra far to meet the rotor the first time (which is a case where this code can come up without really indicating a problem, so no reason not to clear it).

If you have the trouble codes read with Techstream (or anything capable of reading the three-digit subcodes that go with the main code), there are eight different subcodes that can tell you more about what problem was detected. There are five pages in the repair manual (more info) explaining how to isolate the reason this code was set.

 

The booster pump/accumulator is about an $1000 part. When mine was out (I bought the car that way) I found one in a Pick and pull type junkyard for about $25 and it served me well.

I guess if I were you, I'd be on the lookout for a pump motor, a used one will be fine. In the meantime, I'd carry a ball peen or tack hammer and wack it good if it goes out again..

 

If the Innova doesn't work for you, take it back. And buy an old Windows XP laptop, a mini VCI cable, and install the software for Techstream. It really and truly is the best scanner for the Prius. And you can scab it all together for less than $75. Mine worked amazingly well on my 02.

BTW, someone said the obd2 was 97 on, actually it's 96 and later. It was the deciding factor when I bought my Dakota (a 96.) A huge step forward in automotive diagnostics, especially with all the computers that are on autos & trucks.

 

Karen needed the hammer about three years ago.

 

Thank you for your responses, I will try one by one and see how it goes. Will post your response as I go.

Once again thank you ChapmanF and Brian in Tucson.

 

The hazard on not starting new threads!

Luckily, you can get a hammer just about anywhere. For beating on car parts, I like an old fashioned tack hammer. Good for a gentle tap or for really beating the heck out of things.