Ошибка c1241 тойота приус 20

Just trying to troubleshoot these codes/lights and determine what to fix to be able to drive my Prius again.
Used Techstream to get the codes.

This is one case where the typical advice to get a voltage measurement of your 12 volt system really is on point; all three of these codes refer to inadequate voltage arriving at parts of the system (the skid control ECU and the hybrid ECU).

That doesn’t lead straight to a conclusion about the 12 volt battery, though; these codes are more subtle than that. The voltages they are measuring are up at the front of the car, downstream of some fuses and relays, and were probably measured low at moments when the car was in READY and power was being supplied by the converter.

The repair manual will recommend either charging or replacing the 12 V battery if you do not get a 10 to 14 volt measurement of it; beyond that, there are several pages of tests you can do at the ECU connectors and relays to pin down where the voltage drop may really be happening. The second code you listed puts particular suspicion on the ABS no. 2 relay, and has seven pages of testing suggestions.

I’ll tip my hat here to the ‘check your battery’ crowd to start with, and if that measurement comes in within the published range, if it were my car, I would just be right over at techinfo.toyota.com pulling up the manual and the instructions to sort out the other possible causes.

The first code has several «inf» subcodes that you should also be able to see using Techstream (look for the «freeze frame» page, which will probably give you other very useful information, like just what the car was doing at the moment the code was logged, and what the out-of-range measurements were and where, at that moment).

-Chap

Battery is ok.
11.8 V one power button press
12.4 V two power button presses
14.2 V ready

12.1 V multimeter reading

I checked the fuses in the engine and on the drivers side. All good.

How do I check the relays?
I’m looking in the manual now. But if anyone knows off the top of their head…
Can I just pull them out?
Do I have to unplug anything?

a new 12v is 13v. by the time 12.1 volts gets to the computers, it may be below spec.

It’s almost essential on PriusChat these days to say how you took that reading, because some methods (e.g. the display up front) are consistently a good fraction of a volt lower than an at-the-battery reading, and some PriusChatters will leap on it with the usual about tenths of a volt «out of spec», without even asking where your numbers were measured.

I am curious about the «one press» and «two presses» readings; normally «two presses» will be lower, because more stuff is being powered in that mode. Is it possible you swapped them?

Really it’s best to stay focused on the problem you’re trying to solve. You didn’t start this thread because you wanted to check some relays, but because you wanted to solve some problems with your car. What we know about the problems (thanks to the computers) is what’s shown in the manual under «detection condition» for those codes.

For example, for the C1241, depending on which of the four inf codes you have, you may be looking for some reason insufficient current is available to the linear solenoid, or voltage at a BS terminal at the skid ECU is dropping below 8.9 at some moment when the brake isn’t applied, or the actual internal regulator of the ECU is failing to keep its output between 4.7 and 5.3 where it needs to be for 5 volt computer circuits to be dependable.
(Or the capacitor mode issue if your inf code was 83, or ABS trying to function while the relay is dropping, if your inf code was 84).

Where I’m going is: as you work through these possibilities, checking some relays may well be part of what you do, but that’s the means to the end, not the end itself. In fact, there can be various ways to check relays, and you’ll do it most effectively if you keep thinking «why am I checking this relay? what conditions am I trying to convict or acquit this relay of?»

And if that seems like a lot to ask, one very reasonable way to proceed, as long as you’re looking at the manual anyway, is to follow its suggested testing steps as presented, in order.

-Chap

If your referenced the SOC table, 11.4V, w/ a load, shows your battery to be 0-24% SOC. That is weak.

Consider recharging if you have an AGM compatible charger, or relpace.

OK. Now 11.7, still weak.

Just recharge to eliminate a weakend 12V being the cause of the problems. Cheaper than buying a new 12V battery. Most helpful to recharge w/ an AGM compatible charger.

Do you listen to the radio in ACC mode? Single press of Power button, foot off brake?
If so, stop. This drains the 12V unnecessarily. Listen to the radio in IG-ON. The engine will run occassionally to ensure the HV battery doesn’t run down.

11.7 V. Sorry edited it after.
But, I hadn’t driven the Prius for a couple of days and had been fiddling around in Tech Stream all morning, draining the battery.

Took it for a drive. All seems well 12.2 V after doing the same test. But, maybe the drive would impact it?

Techstream tells me: Open Circuit in Main Relay 2.
ECB Main Relay 2: OFF in Techstream

This was the last code. Maybe the other codes were older codes not cleared.

I checked the relays and fuses related to ABS yesterday. Now I’ll have to find the ECB relay and check it.

Where is the ECB main relay 2? I checked the hood. Nothing by that exact name.
That’s what I’m reading/searching for now.

Update:

Motor Relay 1: OFF
ECB Main Relay 2: OFF

compared to

Motor Relay 2: ON
ECB Main Relay 1: ON

Still not sure where the relays are.

Good advice, but use READY mode rather than IG-ON (ACC is one press, foot off brake; IG-ON is two presses, foot off brake, READY is one press, foot on brake and the READY light showing on the dash).

IG-ON will not run the engine to recharge, and in fact will drain the 12 volt battery even faster than ACC, because more of the car is powered in that mode.

-Chap

No worries here. I only listen to the radio when driving.

good luck!

how many miles on her?