Ошибка с1300 тойота приус

Hello, need some debugging advice…

My wife’s 2005 Prius with 93K miles recently started to have the yellow (!) ECB warning light come one. It stays mostly on now, but it occasionally goes off. None of the other red triangle, ABS or Brake light comes on, and there is no change in braking function. The MIL light is not lit, but Techstream indicates a DTC code of C1300, which is a «Malfunction in Skid Control ECU». The freeze frame data indicates a Detailed Freeze DTC of 1063, but I cannot find any info in the service manual about that DTC.

The freeze frame data also shows IG1 and IG2 voltage at 0 V, which I suspect is a clue, as the live data shows normal IG voltage. I’m wondering if the ECU is misreading the voltage, or if it might be an intermittent issue with the capacitor power supply. The service manual doesn’t give much debugging information for C1300. Basically, if no other DTCs show up, replace the Skid Control ECU. The ECU is less than $100 used on eBay, but it’s the thought of dismantling the dashboard that puts me off. So, if anyone has experienced a similar issue and found the solution, I would love to hear about it.

For the record, the AUX 12V battery was replaced about a year ago, but I charged it anyway, so there is healthy voltage.

It sounds like you have your finger on the pulse. The C1300 is a self-test failure, which means that internal routines are not finding what they should, such as the ROM check sum is bad, or something similar. Not much for it but to replace and see, IMHO. Let us know how it goes.

Well, I was hoping someone could provide more information based on the Detailed Freeze DTC. The fact that it is intermittent, and can go on and off while driving tells me it’s probably some self monitoring event/signal being out of spec or being misread, but I’d like to narrow it down further.

In any event, has anyone replaced the skid control ECU before? The manual says to remove the steering column, which seems like a of of work. What is the best way to swap it out with the minimum of disassembly?

Just for the benefit for others who might be experiencing the same C1300 code, I have a bit of an update. All the information seems to point to replacing the Skid Control ECU for this error, so I resigned myself to swapping it and bought a used part. As part of the process of swapping out the Skid Control ECU, you are required to perform a Linear Solenoid calibration. I thought I would familiarize myself with the procedure before I did the swap, so did the calibration with the existing ECU. Well, after I did the calibration, the yellow brake (!) light has stayed off. It’s been two days and the light has not turned on at all. Prior to the calibration, it stays on more than it stays off. The C1300 DTC can still occur and be stored, but it doesn’t turn on the brake light anymore. The re-calibration appears to have done enough to turn off the light, but not enough to turn off the DTC.

I am going to leave it for a week to see if the light comes on again at all, but since I already have the replacement ECU, I plan on swapping out the ECU next week anyway, just to get rid of that C1300 DTC.

Hi there. I am from New Zealand and i recently had my 2005 Prius diagnosed and one of the DTC’s was 1300 with a detailed freezeDTC of 1011. You say above that you were going to swap out the ECU. How did that go? Thanks

The light stayed off for about 5 months and then came on again, so I swapped it out just a week ago. Folks said that you had to drop/remove the steering column to swap out the ECU but you really don’t have to do that. You have to remove the panel on top and bottom of the column and then use a long extension threaded through the vent area to get to the top bolt. After swapping the ECU, all DTCs are gone and the light is off. Looks like once you get the C1300 DTC, it’s only a matter of time before you need to replace the skid ECU. When the light is on, the Prius doesn’t do any brake regeneration and your mpg drops, so you might as well change it out.

Hello. I am experiencing what may be the same issue with my 2008 Prius. The light came on and will go off and come on intermittently; it usually stays on for anywhere between 15-150 miles before going off and staying off for a few days (I drive 180 miles daily, at a minimum)-but it is never on when I am near a garage or have an appointment. Can you give me an idea as to where you purchased the replacement ECU and a rough cost (monetary and time to replace)? Thank you!

First get your fault codes read with Toyota hybrid capable scanner. Fault information stays in the memory even after light has cleared. If you want to read code yourself get techstream. Best if you can get both code and sub code (if there is).

As valde3 indicated, you should make sure you have the same DTC and symptoms before you look to swap the Skid ECU. It should be stored in memory so even if the light is off, the code should still be stored.

As for replacing it, I have no idea what the dealers charge to replace it, since I did it myself. The list price for the replacement ECU from Toyota is over $1000! If you are capable of doing it yourself, the part is less than $100 used on ebay, and should only take you an afternoon. You do need access to Techstream in order to do the re-calibration.

Thanks for the replies-I do need to have the code read yet, it seems that every time I schedule an appointment, the light goes off and I didn’t realize it would stay in memory. I’ll check back in once I have the info.

Hello Speedy7, how did u do the re-calibration. If u can share some details it would be great. I got about 5 codes on ABS unit and C1300 is one of them, and I did notice with Dr.Prius that my charging amps do not go up while braking and my gas mielage dropped ever since these codes came on.

You could include all of the about 5 codes if you wanted to give us more complete information, but the C1300 generally indicates that the skid ECU has failed its self-test. The repair manual doesn’t generally go into internal repairs of ECUs, but just recommends replacement. Before that, it might be good to look at the other codes and see if the manual indicates any way that they could lead to a C1300 also being posted.

It is common for the regenerative braking cooperation to be disabled when such brake system trouble codes are posted.

All 5 codes. C1241, C1242, C1256, C1300 & C1391. Attached are ffd as well.

All of those voltages in your freeze frames are really low, around seven volts or below. That’s definitely low enough where you can start to see logic circuits doing weird things, because the strictly regulated 5 V that the circuits rely on comes from onboard regulators that can need a couple volts of headroom to do their jobs.

So I would grab a meter and focus on finding out why the voltages arriving at the brake ECU and actuator are so low, whether it’s because of the aux battery or something dodgy in the wiring or connections.

Once that is resolved, I would clear the codes, find something wooden to knock on, and see if they come back.

Thank you Chapman, I pulled the ffd and I was like okay, what should I do now. I do not have a repair & troubleshooting manual, once I find that I guess I need to start checking what nominal range should be. The battery for the car is 1.5yr old at most.

Have we got a page for you:

Toyota Service Information and Where To Find It | PriusChat

The trouble codes you have refer to voltages arriving at the brake ECU or at the brake actuator. When they are low, it can be because of the condition of the car’s 12 volt battery, but it doesn’t have to be. You can also have situations where the 12 volt battery is just fine but there are connector or wiring problems dropping the voltage before it gets to these components.

If you have a multimeter, this is just a simple matter of making some voltage measurements, starting with the 12 volt battery itself, and following the wiring diagram until you see where the voltage stops being ok. If you don’t have a multimeter, you have a preliminary problem to solve first.

Nominal ranges in a car’s «12 volt» system are, by design, pretty broad. As low as 11 (and that’s conservative!) or high as nearly 15 can all be seen without ill effect. (Toyota will tell you to charge the battery, if it’s below 11, before spending much effort on other troubleshooting.) That’s why the boxes, like ECUs, that are most voltage-sensitive contain their own regulators to make a strict 5 volts from whatever’s coming in. But the regulators can struggle to make a stable output when the supply isn’t at least a couple volts higher, so that’s why the 7-ish supply in your freeze frames is Definitely Too Low.

Thank you Chapman, I found that page. I see the wire repair manual used for fixing pins and wiring on the vehicle. But anything else it points to TIS which is a subscription service from Toyota. Was hoping somebody got a pdf of the RM & EWD for my 2008 Gen2.

Just a brain fart, my lights flicker sometimes, and the driver side turns off after some time, so wondering if indeed is the wiring issue and may be both are related. I found a 2006 EWD RM01R0U, wondering if I could use it for 2008 as both are Gen2

That’s probably the same 2006 pdf that a lot of people are referring to for their Gen 2s when they are not signed in to TIS.

It’s ok until it isn’t … there can be minor differences between years, and also the manuals on TIS get updated/corrected, which doesn’t happen to a downloaded pdf.

So of course you can look stuff up in the pdf as a first stop. If you run into something that doesn’t make sense or is missing from that copy, you know where to go for the real deal.

Yes, TIS is a subscription service, but you can get two days’ access for $20, which I seem to spend maybe once every year and a half or so. Not a whole lot of money, compared to paying shop rates, or having a car that doesn’t work, or having one that I broke because I didn’t look something up.

Also, that wiki page mentions several other access options that Elektroingenieur went to the trouble to explain there, such as through a local public library, which can be free.

Did not get very far. The Battery is good, 12.73V @ battery. Brake power supply output measured 11.7v (10-14v) is nominal. Ran into trouble trying to get to Skid Control Unit in the dash. Looks like I need to major disassembly of dash to get to it, I removed all panels/skins on driver side but still wont get enough access, looks like I have to remove the lower instrument panel sub assembly to get to it. All ABS fuses are good in engine compartment.