Roommate's Car - C1343

Generally here at this point you're replacing an actuator You can go through the 40 pages or whatever it is of the testing business generally it's all going to lead back to the actuator unless you see brake fluid on your back right rear backing plate pull the drum off see the brake fluid coming out of the line connection or the rubber boots on the end of the wheel cylinder You got nothing. It's going to come back to the actuator. You can buy them used online eBay in the 300 350 range The big places like the salvage yards and Conyers Georgia and some others have enough of these cars where they can send you one right out when it doesn't work Make sure you look at their fine print I've installed several used ones in all the cars are running fine and still working some are 3 years in so more than paid for themselves just in that one repair in the savings because the new one is going to be about $1,400 12 to 14.

 

Do not replace any more parts until you have done a complete diagnostics for that trouble code.

Did you get the Toyota service manual for C1343 and look at what triggers that code?

Have you followed the step by step process to troubleshoot that code?

 

Roll the car up on ramps it'll take you a whopping 20 minutes to look down the tray and look at all the brake lines If anything is compromised you seen it before on your Rover I've seen it before on a 93 Corolla right here in the southeast United States. So you know what that looks like and anywhere there's leaking brake fluid it's going to look like power steering fluid shiny oil but it's not it's glycol I understand but you'll see it If there's none of that going on then more than likely looking at your actuator and that's just the long and the short of it I've gotten actuators for 50 bucks at junk yards bought two at one time from a guy claiming to rebuild them I paid him for one and he sent two I used them both and they both worked flawlessly they're still working today can't find the guy on eBay or anything just vanish not even in my history is the funny thing it's weird. Typically on eBay from the junk yards down in the southeast they go for about 300 325 something like that. Realizing that many of these things have been replaced and then the hybrid battery goes bad and the person sends the car to the junkyard this is a real scenario that happens probably almost on a daily basis with these cars so a lot of these actuators if you look carefully some of them are looking brand new probably because they are I've bought a few rolling chassis for $700 or so was recently replaced hybrid batteries and door brake actuators like the receipts in the glove box or you can tell it by looking at the parts like brand new and the rest of the car is not and that sort of thing

 

C1343 isn't specifically a fluid-leakage code. It's a "hey, I'm having trouble holding the desired steady pressure in this line" code.

I do see that there are various INF codes, and the detection condition/trouble area table says "fluid leakage / actuator / disc rotor" for some of them, and only "fluid leakage / actuator" for others (including the INF code the OP has).

However, the troubleshooting instructions don't make that distinction, and give the same set of tests for all cases. Leakage is one thing to look for, then the wiring between actuator and skid ECU, and then the believability of the pressure sensor reading for the affected line.

If it were me, I might rearrange the order a little. Checking all the wiring connections sounds tedious. I might go ahead and check for sane sensor readings first. If the readings are ok, I might skip checking the wiring (unless I suspect an intermittent).

The official check for a sane pressure sensor reading involves plumbing in an LSPV gauge so you can compare the reading to what the gauge says. But that's a PITA and who's got an LSPV gauge lying around? Of course you can approximate the test by just watching the sensor readings while you step on the brake with a few different levels of force. (How do you know you're applying 1, 3, 7, or 10 MPa of pressure? Well, you don't, but shucks, the code is only complaining about one of the pressure readings, so you can watch the other three and see if the right rear is in the same ballpark, or what it looks like it's doing instead.)

They also have a pretty easy test for a wobbly rotor. That can lead to the code because the pressure wobbles as the rotor turns.

In old-fashioned cars, a wobbly rotor is something you'll feel through the brake pedal, but the Prius ECB does such a good job masking it that you don't. So what does Toyota suggest? Just unplugging the pedal stroke sensor. That's enough to set another code where ECB won't try to operate, et voilà, if the rotor wobbles you can feel it in the pedal!

 

As Chapman suggests, clear the code and look at the data. See if both rear sensors show "the same" while pressing on the brakes (both standing still and while moving - record the data to check it while not driving).



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That's the speed sensor It doesn't really have anything to do with break fluid hydraulic pressure in the system so let's not worry about that unless you see one that's ripped out and just hanging which is possible generally highly unlikely but it can happen usually on brake jobs. The pressure sensor that would read the pressure sensor that Chapman's talking about I'm pretty sure is inside the actuator It's not user serviceable except by replacing the actuator which is where all this is generally going to lead to unless you have a very strange bunch of business going on like rodents in the car chewing up wires You got mice You can find them easily and the traces of them you got chewed up paper towels on the floor of the car etc etc etc I don't know where this car is parked I know it rained yesterday that's about it have you driven the car around your neighborhood at 10 mph instead of the 2:00 to 3:00 Just for the hell of it I'm not saying do it in the hills of San Francisco like the Rice-A-Roni commercial I'm just saying the car stops the car backs up and stops The car goes forward and stops when you approach a stop sign does it feel like it's taking a lot longer for the car to stop in the pedal has to travel a lot farther so on and so forth doing this is not going to cause you necessarily to have an accident and kill 15 people You're only going 10 mph you'll be lucky to damage a fire hydrant I have a driveway that's long enough I can do this but I still go out and do the street in front of my house nobody cares sometimes not even with a tag on the car oh well so I'm not sure if you're having stopping problems or just lights that are on and some low pressure that I can see and what not in the texture typing. For wiring to just be damaged between the skid ECU and the other ECU that's quite a stretch I mean what's going to damage it has somebody plowed into your car and put the engine into the firewall moved a bunch of wiring around probably not because the car wouldn't be being discussed probably. Rodents would be the other usually you get clear signage that rodents are using your car for shelter food and what have you just like a homeless encampment. Wires just don't rub together because they're sitting there and doing nothing to the point where they rub through cause shorts and ruin everything not saying it's not impossible just the likelihood generally isn't a thing but then being chewed through is quite real in some parts of the country I have some mice living in a 2010 right now they're not bothering anything in the car they're laid up in the spare tire well they're babies I don't bother them. Matter of fact I took one of the holes out in the spare tire well and it looks like they can fit through them and go out so when they get ready to go become bigger mice they'll probably just leave More interesting things to do but so far they haven't chewed up the car it still starts and all of that.

 

Sorry to bear bad news, but this code is about the fluid pressure sensor. The pressure sensors for all four wheels are built into the actuator assembly and not replaceable on their own.

 

I certainly don't think any such thing as I have a couple of cars with drums on them and wheel cylinders that have 400,000 mi on them almost without any problems out of round drum wouldn't cause this or any of that stuff. I think what Chapman's talking about is wiring from the skid control computer to the other ECU or even out to the actuator so wiring from under the dash way over I think by the passenger sides seat person's right foot would be above it or somewhere in that area I believe is where these computers are or they're in the center same height but in the center of the dash or even over on the driver side no matter You're pulling all these panels out to inspect these plugs and look at these wiring harnesses that run all across the car and then maybe back out to the break actuator after it goes through some other electronics so all those big wire looms that are wrapped with that vinyl etc You're looking through all of those for a short a loose wire a wire pulled out of a connector on and on and on that You could be down there for days I would think if things like that were going on other things would become intermittent 12 volts would just vanish out of the battery all kinds of interesting things you would think but hey what do I know I'm just a poor slob with four cars that are running pretty good and we don't spend a lot of time chasing down too much craziness all the break actuator jobs have been just that break actuator jobs not messed up wiring none of it so there's always that I don't start looking for chewed up wires as one of the first things I do on vehicles where I am here because it's not a real big thing It can happen but it's just not something that in the paper everyday so yes you're back to the actuator and this is where it all starts generally.