Prius quite running and won't start with codes U0073, U0123, U0124, U0126, U0293, POA72

I always say a lot of codes all at once for the first time is usually something that's gone unplugged, or a fuse that needs to be replaced or bad 12v or its connections... How many miles? Any recent maintenance or other symptoms?

Once you check everything for the obvious clear the codes and let us know what comes back first and how quickly it happens.

 

As you are using Techstream, you have an advantage here: the health check screen shows the codes grouped by which ECU reported them. You can help us out if you preserve that information for us when you post it. That is especially important for all U codes, because those are communication codes, and they mean that something in the car can't communicate with something else. The code itself tells you what the something else is, and the something is the ECU that reported the code.

Also, it's handy to know that the second character of a code won't ever be the letter O because it can only be digit 0, 1, 2, or 3. So if you search a forum or the internet for P0A72, you are likely to get more search results and better ones than if you type it as POA72.

 

If you don't have a way to read & clear codes you can disconnect 12v battery for a few minutes to clear them. But getting a Mini-VCI plug for Toyota Techstream or an OBD2 plug for phone apps to read & clear codes should be a high priority. Let us know if you need help with that.

 

Yes it sounds like that maybe the case so you should have the red brake light the VSC and I don't think your car will have traction control but I'm not sure about that and they should never go out does your brake pedal feel like it's working properly I drove my car for almost 2 years with the ABS VSC which is vehicle skid control and the red brake light like the parking brakes on for that whole time and the brakes worked perfectly I had no ABS. But the brakes work just like a Corolla four-wheel brakes without ABS if I stepped on the pedal too hard I could smoke all four wheel wells looked really cool but that was about it. So you may well have a bad break will call it the actuator which is the part with the pump that makes all the noise it whines when the car starts is turned off two of mine have done this exact same thing I just fixed the '09 days ago successfully good luck

 

Do you think you could find a moment to double check? Sometimes people post a screenshot of their health check screen so we can all have a look.

I wouldn't always doubt what you said, but I didn't think P0A72 was an ABS/VSC/TRAC code, so something strikes me as fishy.

The place you can find all the diagnostic info you're looking for, and what to do to understand the codes, is the repair manual, as described here:

Toyota Service Information and Where To Find It | PriusChat

When you post the codes and information here, we can often offer some pointers; it's fun to help out. But ultimately we're giving you the same information you can find in the repair manual, so if you ever get impatient waiting for us to reply, or you just want to get a more first-hand grasp of the info, it's never a bad idea to look there.

For U codes, especially, the troubleshooting can be kind of involved. There's a lengthy section in the repair manual about it, and you might find it easier to have that in front of you than to do a whole lot of back-and-forth on the forum.

 

The more we know about the codes you currently have, and which ECUs are reporting them, the more we can offer as you diagnose your situation.

It's possible the codes now might not be the exact ones you had before the recent part replacement.

 

Ok. So if we look at the codes, AND we look at the ecu's that didn't report on the health check, it looks like something is wrong with the CAN communications network.

Some ecu's only use CAN to talk with other ecu's (ie, function) and then use another network - SIL - to talk with a scantool (diagnostics) Others (ECM, Hybrid Control, and HV battery) use CAN for both function and diagnostics.

The ABS ecu can't talk to most anything else (except a scantool on SIL). ECM, HC, and HVb can't talk to a scantool (on CAN). But at least HC and HVb can talk to the rest of the car (on CAN)- otherwise the hybrid system would be dead.

Put it all together and I expect that there is a damaged CAN wire or poor connection somewhere. The codes might suggest that it could be "between" the DLC/OBD2 connector and the steering angle sensor. Possibly Junction Connector 1? You have to get wiring diagram and start checking.

A preliminary test is to disconnect the 12V battery then use a multimeter to test the resistance across pins 6 &14 of the OBD2 connector. Do not jam the meter tips into the terminals- you can damage the the connector. Gently touch the tips to the metal terminals. Resistance should be around 60 ohms.

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Here's a brief for the CAN network.

Posted via the PriusChat mobile app.

 

edit:

couldn't quite see in the first picture - but the health report DOES show the HV battery ecu. Doesn't change my opinion that something's wrong with CAN. Might be a missing power or ground to the ECM.

Posted via the PriusChat mobile app.

 

Any updates on this? im having the same issue with codes popping up u0123, u0124, u0126.

2009 Prius 157,000 miles