Short Caused U0293

Could you give more detail? You mention the "hybrid battery" (which is the large, high voltage one under a long metal cover), but you don't mention which battery's positive cable you were tightening, or what you touched the hybrid battery with, or what part of it, or what its cover was doing off, if that was the battery you mean.

 

Can you give us more details... Like specifically what part of HV battery was touched and with a metal tool? Did metal tool also touch positive terminal of 12v or positive terminal of HV battery?

 

How can you still be alive if you managed to arc the hybrid battery

 

Try to reset with a code reader

 

Keep trying to disconnect 12v for a while so system will reset... I've not heard of something like this frying that controller, but it's certainly having a hard time re-configuring. Also Patrick has some fuses to check and other things to try here: U0293 Lost Comm w/ Hybrid Powertrain Control Module | PriusChat

 

In that case, it's just that the metal cover is grounded, and you touched your ratchet to grounded metal. Much less exotic situation, doesn't matter much that the grounded metal was the traction battery cover.

U0293 is an ECU in the car saying "hmm, I can't communicate with the power management control ECU". Commonly, with these U (communication) codes, it is also helpful to know who the "I" is in that sentence—that is, which ECU is reporting the U0293 code? Some scan tools give you that information, but others just show you whatever codes were received and not where they came from.

U0293 can be "said" by the ECM, the steering ECU, the skid control ECU, the body ECU, the certification ECU (for smart key), the A/C ECU, or by the driving support ECU (if you have the pre-collision, DRCC, lane keeping, or parking features).
It can even be said by the power management control ECU itself, which seems weird, but there are two or three different 'virtual' controllers running in there, so it means one of them isn't communicating with another.

The energy of the brief short and arc might have damaged the transmit or receive electronics in one of those. Troubleshooting steps in the "CAN communication system" section of the repair manual can help pin down where the issue is.

Couldn't hurt to look at some fuses; that'd be a lucky break.

Toyota Service Information and Where To Find It | PriusChat

 

Right, "lost communication with Hybrid Powertrain Control Module" is what the U0293 code means. (As a U0 code, it has an SAE standardized meaning. The specific Toyota name "power management control ECU" is what SAE generically calls the hybrid powertrain control module. Two names for the same thing.)

The thing about communication error codes is that it takes two parties to have a communication error. The code itself tells you who one of the parties is. The other party is whichever ECU in the car is giving that code. So it is helpful to use a code reader that not only tells you what code was reported, but also who reported it. As you saw in post #11, there are about eight possibilities.

The flashing red car-with-a-lock light is one that normally flashes when the car is off—a feature conceived to alert thieves that the car has a security system and they should go steal somebody else's. Sometimes people own the car a long time before noticing it. Would you say it is blinking in a different way than it normally does?

 

Any scan tool that groups the codes it receives according to which ECUs in the car it received them from.

Techstream does, of course.

Back in March, I noticed the Car Scanner phone app also does, when I saw someone post results from it.

 

The repair manual. Troubleshooting steps in the "CAN communication system" section can help pin down where the issue is. It has tables giving you the likeliest places to jump in based on which communication codes you have and which ECUs can't communicate with which others.

It is a section with comprehensive information and details and, for diagnosing network communication issues, that's what works. We might be able to help with any puzzling bits while you work through with the manual, but it's less likely that we far away forum folks can muster the concentration (or even type fast enough) to be much help without the manual. Comm issues are just like that.

Toyota Service Information and Where To Find It | PriusChat