2005 Prius Electrical Issues

I spent the better part of today troubleshooting with no success.

The Back Story (possibly irrelevant)
About two weeks ago I change all the cabin lights over to LED. Worked great. Last week I found mouse droppings in the Prius. The usual suspects made a nest above the cabin air filter. I cleaned it out. This past weekend we went out of town and parked at the airport. The wife came home a day early and the Prius got her home safe and sound. She however still smelled the mice and did a deep cleaning. That Night she tried to start the Prius and received the error...

"there is a problem with the transmission "p" lock mechanism.Park your car on a flat surface and fully apply the parking break"

The diagnosis:
Naturally I think that she ran the battery down while cleaning and that a jump is in order. I hook up the kit and same problem. The MFD gives the Red triangle with Problem and then asks me to repark. Also, all four gears on the display flash with a box and the fuel gauge flashes full.

Still suspecting the 12 v I dig into the battery (about 18 months old) and haul it to napa. It passes their test but shows that it needs recharged. I go home and hook it up to the charger for 2hrs till the green light say it is good to go. I hook everything back up and same error. While the car is starting, the engine will sometimes start up for 20 seconds until the problem message appears. I can here the transmission shifting and twice it actually went into drive and lurched forward before the problem code appeared and everything shut down.

Some weird details:
The last 6 months I have occasionally seen a P1121 Code for the Inverter Bypass. Sometimes it stays around for a week, sometimes it clears on the next drive. I have not replaced the valve yet. Also, since last night the smart key and power door locks do not work. The climate controls bring up an error message to check the connection.

Things I've Tried:
I have tried two different Optima Batteries in the Prius. Same results. I have tried jumping from a box and another car. I have checked all fuses that say anything about Ignition, door locks, parking imolbilzer ect... I have not found any bad fuses. I have tried rocking the prius, shifting various gears at various times, reseeded connections in the dash and looked everywhere for those pesky mice.

Any thoughts? I am at a loss. I suspect the MFD is acting up, but that shouldn't affect the powertrain right?

 

Transmission or engine oil? Last oil change was about a month ago. I will look at that in the morning. I'm not sure I remember ever seeing a traditional oil stick for the transmission.

The cleaning was carpets and vents.

 

She used a shop vac and wetwipe with peppermint oil.... it is supposed to repel rodents. The problems seem similar to Dan Strnad's Prius except for my MFD is displaying just fine.

 

A quick update. I had the prius towed to an independent shop. He went through the electrical system and originally thought the 12 v was bad. A replacement battery did not help but the mech noticed a voltage draw on the battery. He diagnosed a short in the parking actuator and tried replacing the it. Still no wins. The prius is now waiting for a specialty tool that we interface better than the scanner the mechanic currently has. Certain modules won't power up (door locks, abs, air conditioning) so I am still convinced it is electrical.

 

Another update to hopefully help some one out. I gave up and took the Prius into an independent shop. They diagnosed a bad 12 v battery and switched out the optima under a Napa warranty that I had. This did not resolve the problem but the said there was a constant amp draw from the battery. They then diagnosed a short in the parking cowl and replaced the motor with a salvage unit. This did not resolve the issue either. Upon switching to a new diagnostic system, the mechanic said that he could see all of the relevant computers in the Prius system but could not get them to respond to commands.

Many days later, 4 weeks, he unplugged the BCM and the Prius started up and would engage the transmission. The mechanic said I would need a new BCM from the dealer as Toyota states that they cannot be salvaged as programming is unique to the vehicle. The mechanic wanted to try a used BCM anyway and sourced one for $90. After replacement, the Prius started and ran like normal. The mechanic said that something in that computer shorted, though the unit is part of the interior fuse box so any of those pieces may have been the culprit.

So I was without my car for 6 weeks total but it is up and running again. The cost was about $1k mostly in labor. This is the first major issue that I have seen and hope for another 160k before any more issues.