Need help getting blink codes

A search kinda like this ought to turn up threads with the info.

You'll see what the diagnostic connector looks like. Its location is under the dash, sort of above your knees.

 

Cribbing from a 2010 liftback repair manual (ought to be pretty close...)

We call that one the "ECB light" (electronically controlled braking).

41 corresponds to the full trouble code C1241.
57 is C1257.
69 is C1391 (see, you were probably about to guess you can just put C12 in front of a blink code, but it's trickier than that.)

42 on the ABS light just means "hey, did you see the codes on your ECB light?". Same with 45 on VSC.

Those mean your TPMS receiver isn't getting signals from two of the in-tire transmitters (the ones registered as ID1 and ID3). Probably those transmitters' batteries have run down. It's been a pretty long time.

Inconveniently, those ID1 or ID3 slots don't directly tell you which two tires on the car they are. But a tire shop probably has a handy wand they can use to see that.

Back to the brake codes ...

C1241 pertains to low voltage arriving at the brake actuator/ECU. It doesn't have to mean the auxiliary battery (you said that's fairly new); if it isn't that, it's probably a deteriorated wiring connection somewhere in the wiring path from there to the brake actuator. There are several different INF codes that pin down the situation further, but you can't get those with light blinks; that takes a scan tool.

C1257 is about the brake ECU being unable to run the pressure pump when it needs to. There are two INF codes, which (if you could get them) would tell you whether (1) the pump didn't get power sent to it for 1 second or more while the pressure was too low, or (2) one of the three built-in motor relays didn't operate for a fifth of a second or more when the ECU wanted it to.

C1391 is the code everyone hates, because you usually get it when your actuator is toast. But while that's often the story, that's not exactly what the code means.

What it means is that either (1) the fluid pressure isn't going up when the pump is supposedly running, or (2) the pressure goes down too fast when you're not braking and the pump isn't running.

Sounds bad, but in your specific case, notice you've already got two codes indicating an electrical issue that is keeping the pump from working right. So in your case it's really not surprising that the pressure doesn't rise when the pump is supposed to run!

So, if it were mine, I would start by looking hard for the electrical issue(s) behind the C1241 and C1257, get things back to where the pump runs when it's supposed to, and then see if the car still wants to say C1391 or not.

 

get a free battery load test at an auto parts store, just to eliminate that possibility

 

So far twice I've had the same set of lights and exactly the same scenario with similar codes but I never blinked because I have a scan tool. And both times on both cars 04 and an '09 generation 2 each car got the brake actuator pump assembly thingy the one that's buried behind the inverter with most of the brake lines going to it so that's all I know so much about that I've not been lucky enough to find any deteriorated wiring yet of course I'm in the southeast United States where we don't get much deteriorated wiring or rust but that sounds like what you're heading to.

 

Ideally you'd like to find a repair shop in your town or nearby that does work on these vehicles and does a good bit of it and stay away from the dealer as much as possible you can do way better than $2,000 on replacing your ABS pump and actuator I can guarantee you that I could do them all day long for 3 or $4,000

 

The "readout" on the MFD screen is good to within around 0.5V. Using a multimeter at the battery or at the underhood fusebox is much more accurate.

That said, 13.9V indicates that the car is in "ready" mode and the DC-DC converter is supplying around 14.0V to run the low voltage system and charge the 12V battery. Can't use this to figure out battery condition.

Posted via the PriusChat mobile app.

 

In my experience, the MFD has been more accurate than that description would suggest. I've been seeing it to read on the order of 0.5 V different from a reading at the battery (or the diagnostic port pin 16), but the difference is consistent; once you've worked out what the difference is in a certain condition (ACC, IG-ON, READY), you can kind of bank on it, and add back the difference you know to get pretty close on a battery or OBD-port reading.

My take is it's probably a reasonably accurate voltmeter, just one that's inside the MFD and happens to be reading the voltage that reaches it there.

 

A lot of cars have fancy brake systems these days.

The chief thing that makes the Prius one special is really a matter of software, just the way it asks the powertrain "how much slowing can you do?" and then says "ok, I'll take care of the rest." The valves, hydraulics, pressurizing pump, etc., by themselves aren't super hybrid-specific anymore.

Here's a main thing I notice about shops ....

If this car were mine, I'd be thinking "let me check into these electric-power-to-the-pump codes first, see if I can find a simple reason the pump isn't working, and fall back on replacing the $$$$ part if I don't."

But a lot of shop techs find that kind of troubleshooting to be tedious and less automatic to do than just swapping a part. So there, the order might be more like "we'll replace this $$$$ part, then if that didn't fix the problem, we'll look for the simple thing that would have."

Enough of the time, the $$$$ replacement will fix the problem (maybe even in cases where an electrical connection was dodgy, because a bunch of those will have been unhooked and reconnected in the course of the $$$$ replacement).

 

no, that's just the charging voltage. a load test will put a load on the battery (like the car would using headlights, radio, hvac, etc.)
then takes several measurements. it's really the only way to determine the health.

 

our daughters are the same way. even our son for that matter. they never took an interest in any practical life matters i tried to teach them. had to learn everything the hard way, but so did i tbh

anyway, they turned out okay, it's never too late to learn something new, and keeps life interesting.

i still learn a lot here, i just wish i could remember it