Brake, ABS, (!) lights on

5-6 years is probably average. more in cool climes, less in hot.

 

There is no time based interval. Given it is a $200+ item, just replace it when it can no longer hold a charge.

 

If it is the OEM 12 V battery, there is a label obscured by the tie down bar, so you need to swing it out of the way. The label just has a 6 digit number with the date encode in DDMMYY format.

Part of the problem is I think ((!)) is the Electronic Brake Control system light in the manual, but am not 100% sure. Even more confusing is all three light DTC lists are in the "BC" section that is headed up "Brake Control – Electronically Controlled Brake System" In addition, the problem with the two digit codes is they are unique to the light, but can be reused across lights, So using your ABS 42 code as an example, there is no 42 in the ABS DTC list, but there are 2 42 codes listed in other system DTC lists, namely Tire Pressure Warning and Electronically Controlled Brake. I am not really familiar with looking up the two digit codes as I use Techstream and get the 5-char codes (which incidentally are unique across the entire system, I was hoping @ChapmanF would pop back and offer his expertise with 2 digit codes. Is it possible that the ABS light blinked out an ECB code? I don't know, but I would think not. Therefore, I would rather not put out anything, rather than give you bad information that leads you up the wrong garden path.

If you look back to the TPMS codes, in the last column there is a page reference for each code (TW-35, TW-43, TW-52), this is page where the diagnostic troubleshoot tree begins and you work your way through the steps until you uncover the problem, which you then fix. I'll attach the workup pages for ABS 34 so you get an idea of what information is there.

Hope that helps, somewhat.

If you would like a electronic copy (PDF) of the 2006 PRIUS Repair Manual - 2006 PRIUS Electrical Wiring Diagram, you can download it from the link in this post. (Be warned, it is 5149 pages long, so is a bit to handle and could take a while to download on slow connection.)

 

Well, the codes from the computers can be very helpful, but they don't just flat out tell you what the problem is. The computer can only tell you things based on what it can detect, from a fixed location trapped in a box in your car, without eyes, or opposable thumbs. It's still your mission (should you choose to accept it) to think of the possible things that could happen with the car that could lead to that computer detecting what it detected, and then use your hands, eyes, and instruments to check those stories one by one to see which ones you can rule out and which one seems to fit.

That's where the Repair Manual comes in (techinfo.toyota.com). It has a section devoted to every code you can get. The section will start off by saying exactly what the "detecting condition" is, a/k/a the real-world situation in which the computer is programmed to set off that code.

Here's an example for a code you don't have, in a car you don't have, just because I have a 2001 book handy. In a 2001, you could get ABS code 64. The one-liner title, "Hydraulic System Malfunction", tells you bupkes, no better than a fortune cookie. But you can turn to that page in the manual, and read the detecting condition, which tells you that code gets set when you use the brake and, for one second or longer, the system's pressure sensors don't read equal pressures. That gives you the information you can use to start thinking about what situations could make that happen.

Then the rest of that section in the manual will be a flowchart of things you can test, one by one, until you have pinned down what was causing that. Sometimes that fits on a page, sometimes it runs to several pages. That's what dolj meant by the 'workup'. The manual just steps you through the stuff that's worth checking to find what caused that code.

If you look back in post #11 at the screengrab dolj posted of the TPMS codes, notice the last column, See Page? If you were in the manual online, each of those blue page numbers would be a link, and take you right there.

Which reminds me, I wonder if the '42' ABS code may be in your 2007 manual, just perhaps out of order, and that could explain dolj not finding it. There is a 42 in my 2001 book (do not assume this is the same for your 2007, codes can and do change between generations, check the 2007). In the 2001 it would be set if the ABS computer lost power at its IG2 input pin for at least 7 seconds while the car was moving a few mph or faster.

The lists in the manual are generally in order by the full DTC (the five letters/digits you would see on an actual scantool). The two-digit blink codes are often, but not always, the last two digits of a DTC, but that means they are not all in order when you look at the same list, so it can be easy to think one's not there if you don't see it where you'd expect it.

By the way, the screengrab from dolj in #11 looks to be from the summary list of DTCs at the front of the TPMS section—see how column 2 is the "detection item" (just the fortune cookie, doesn't tell you much), not the "detecting condition" (the real low-down on what sets off that code). For that you have to flip to the indicated page.

Apparently I lied, and at least in Gen 2, it does!

-Chap

 

That is one of the 2 I mentioned. It is in the ECB DTC list.

As an aside, the ((!)) light in my owner's manual is labelled "Brake System Warning Light" and comes in two flavours, yellow and red.

 

I'm sorry, I missed where you mentioned it; I must only have been looking at where you said there didn't seem to be a 42 for ABS, in post #8.

The brake codes got weirder in Gen 2 and Gen 3 because there's really just one ECU in charge of the brakes and skid control, but it can blink several different lights on the dash (red brake warning, yellow brake warning, ABS, skid...) and the codes blinking out on each light are in different categories ... if a 42 was blinked on the ABS light specifically, you have to be sure to find it in the right list.

I think, per U.S. regulations, in this market the red one is spelled out BRAKE, and the yellow one is a ((!)) pictogram. The manual I found on techinfo did show the red one as possibly either word or pictogram, depending on where the car was sold.

-Chap

 

That was my thought too, and it definitely is not in the ABS DTC list. It is in the TWS and ECB list. Definitely not TWS, but possibly could be ECB. if that's the case then it's possible.

(Qouted here so we all don't have to go back and keep referencing post #7 on page 1. LOL)

If ((!)) is the ECB DTC list then 41 is on it, but 36 is not. 36 is on the ABS list though, as well as on the VSC list. I don't want to post info about 41 just yet, because if it is wrong, all it will do is set off the "your 12 V battery is shot" brigade.

34 is on the ABS list, but 42 is not. I already talked about 42 above. Interestingly, 41 and 42 on the ECB DTC list go together. Is that just coincidence?

Can you provide any further guidance, Chap?

 

What manual are you referring to? I wonder if there are some additional differences between US and NZ versions. I'm not signed in to techinfo at the moment ($15 isn't a horrible price, but it's enough to blunt my impulse to sign in again for every interesting question on PriusChat) so I can't really scrutinize the manual right now, which is what I would do if the car were mine. Somewhere toward the front of the brake section, the DTC retrieval instructions should state quite clearly which dash light goes with which code list; that much I (think I) remember.

-Chap

 

Post #8 called your attention to the left rear speed sensor.

I'm not a fan of the two-digit blink codes because the repair manual does not actually document all of the possibilities.

If you plan to DIY, you would do well to get Mini VCI so that you can retrieve the DTC.

 

Fairly sure it is geared towards US models, as I noticed the CHRS canister in one illustration. As well the steering wheel is on the wrong (LH) side . There are no helpful annotations as to which market, nor model year range (that I have come across, yet) to indicate to what Gen 2 Prius it applies.

Ok, will go look at that. With 5149 pages of info to look at, I haven't got very far with my flick through.

 

As always, Chap, it was as you said. So, the manual says which light go with which lists:


It gives the names it is using:


So, helpful, as it confirms my thinking was correct, but still doesn't help finding the codes.

 

Y not get a tech stream, and scan that car?
If it showed the rear speed sensor thingy, try troubleshooting the possible scenarios there.
Have you checked the level of brake fluid in the reservoir?

 

lets hope its not the abs brake pumps, the extended warranty ended in 2017 and its about a $3000 repair..

im not buying any more Prius' until i can get a deal on a 2014 or newer.

 

I had never noticed or heard that until just now. I've never received any in my Gen 1 or my Gen 3 that weren't in the book. We're struggling to find a few in this thread (or, we'd all be struggling to, if I weren't too cheap to pony up my $15 and join the struggle myself), but so far I've been assuming there might be reference sources of dubious provenance involved.

Are you repeating solidly sourced information when you say the repair manual leaves some out?

I haven't downloaded it to check, but it's possible it could have come from techinfo originally, by way of somebody who signed up, then spent a bunch of time doing print-to-file, then posted it online somewhere to solve the problem of technical writers and translators being paid too much. But part of the reason that, so far, I just keep handing Toyota another $15 now and then when I need to look something up, is, it's just a lot easier to use that way. I never notice it's 5149 pages (or whatever, sheesh, my 2010's must be even longer), I just use the table of contents links, search, and the hyperlinks all work, the wiring diagrams let you select a component and follow the whole circuit around, etc. Making a dead, 5k page, non-hyperlinked PDF out of it seems to make it a lot harder to use, judging by what people post who are trying to use it that way.

-Chap

 

From what I have documented in this thread would seem to indicate that. Unless you're assuming the manual I'm using is not sourced from TechInfo. It looks TechInfo to me, there is an example (the 34 workup is a 5 page extract from the manual) attached a few posts back.

The only other possibility is that some of the (2 digit) codes are listed in the wrong DTC list. I am actually inclined to be leaning this way. Reading the codes with Techstream (or other Prius capable reader) and comparing the 5-char codes to the 2-digit codes will confirm this.

PS The other disadvantage I see with 2-digit codes is, if there are INF codes, you don't know about them, and, even thought they are documented in the manual, you cannot make use of them. The overarching advantage is you don't need any special tools (other than the SST paper-clip) and you do get some specific information, which is still better than groping in the dark.

 

A followup on this thread concerning the few 'mystery' blink codes that can't be found in some editions of the Gen 2 manual (36 on ECB, 42 on ABS, 43 or 45 on VSC): more here.