C2310 P Lock (red triangle) w/ Good Battery

I have a 2007 Prius with 205k that has been giving me a persistent C2310 code for about a month (Open or short circuit in battery circuit). I tested the battery at the terminals in the trunk and it reads 12.5V (after sitting overnight with the car off).

The only clues I can gather from my OBD freeze frame info is: Main relay - Abnormal, Battery voltage value - 0.00v, lg(+b) voltage value - 0.00v, U phase voltage value - 0.00V, V phase voltage value - 0.00V, W phase voltage value - 0.00V.

When I pull up live data it shows: Battery voltage value 1.25V, lg(+b) voltage value - 13.67V (U phase, V phase, and W phase are all slightly above 14V), Main relay - Normal.

When I attempt to erase/reset the codes, the red triangle instantly comes back on.

In addition to checking the battery voltage at the terminal, I inspected/checked to make sure the battery terminal clamps were tight and the P Con main fuse was good. I also, through some hunting around on this site, found a possible fix that I ruled out - Due to the low battery voltage on the live data, I found a similar post where someone had .62 volts (mine was 1.25) and he found the pin #13 on the transmission control computer was corroded and installing a jumper wire, which resolved the issue. I have no corrosion on that pin or within that wire harness connection.

Any guidance anyone can provide on this as to how and what I can rule out next would be greatly appreciated.

Thanks,
Glen

 

Thank you both for the advice. I'm guessing this issue has to be from a loose connection at the pin. I merely took the connecter apart again to visually inspect pin 13 to see if I could detect any damage at the terminal (none that I could see) and snapped it back together. The red triangle is now gone and when I ran my ODB with live data, battery voltage value was 13.59V and main relay was listed as "normal." If this pops back up I'll check the resistance to re-evaluate and confirm. My wife also told me that she hit a large bump a few weeks ago and the triangle disappeared for a little bit afterwards, which would also likely indicate a loose connection. Thanks again for pointing me in the right direction!

 

Yeah, pretty much spot on. Today going into work the red triangle was going on and off fairly rapidly for about the last 15 min of my drive. I plugged in my ODB and the battery voltage in the transmission live data was reading about 7 volts. When I pulled into work I left the car idling and popped the hood to further look at the live data. Fortunately, I have a bluetooth OBD so that I could look at the data on my phone while wiggling the wires. I don't believe my live data is instant (seemed to be a little bit of a lag), but after moving the wires the voltage slowly went up to 10 and then back down to about 6. I'm going to take a closer look this weekend. My guess (and hope) is that it's a loose connection at lucky pin number 13. Thinking that the triangle light was coming on and off due to the car hitting a section of highway with some noticeable expansion joints that rattle the car every other second,

 

Just wanted to circle back to this in case anyone had the same issue. New/good battery. Fuse was fine, on my OBD reading the voltage was reading anywhere from 1 to 6 volts, tested the points with a multimeter and would get 12+ volts.

As odd as this fix seems to me, the short 8" jumper cable going from the right hand side of the fuse to the blue wire fixed it. My OBD reader shows 12+ volts now. $7 fix (for the 16 gauge wire). Wonder what that would have cost if I brought it in to a dealer garage?