Inverter Assembly

First, i want to thank you, Patrick, and the other Prius gurus who have taught me so much about my hybrid gem.

So a few questions about invertors. I think mine might be fried after a 2ell meaning brother in law reversed poles when jump starting dead 12v in a Gen 2 with a measly 149K miles. Fusible link is replaced as well as a few other blown fuses. Got a P2118 code which disappeared as soon as a new 12v battery was installed. Now I still get 6-10 seconds of engine churning before the stutter and stall. I checked the voltage across the new 12v terminals at Ready Mode and get about 8.7 volts. Is this always traced back to the bad inverter? Could this be a lame traction battery? Would a dead/dying traction battery give off any codes? The only codes I am currently pulling are 3190 and 3191. I don't have an old laptop that would enable me to utilize the Mini code reader.

 

With 8.7V across the new 12V battery terminals when the Prius is READY, either the DC/DC converter in the inverter had failed, or else the 100A DC/DC fusible link has blown. If you have replaced the fusible link and if the wiring to the inverter is good - then I would say you have to come to the conclusion that the inverter needs to be replaced.

 

Thank you Patrick. That is what I thought. I hope there is nothing else lurking there as well. Time to source a refurb inverter.

 

$495 here if you exchange the failed part.
04 and newer Prius Parts Cars

$135 on eBay.
prius inverter | eBay

 

Thanks Patrick. I found one for $240 including shipping with a 6 month guarantee. Just a few clarifying questions concerning the HV battery, please. Would a dead traction battery give a low voltage across battery terminals? As long as the engine is turning over for that 6-12 seconds, can I assume my traction battery is still functioning? How do I test the traction battery without an HV charger? Would I receive any codes on the OBD if the traction battery is bad? I want to be sure that isn't the problem before I shell the $500+ for an invertor install. Thanks for all your help Patrick.

 

A traction battery can have several issues. For example, a battery module could have an electrolyte leak, causing a high voltage ground fault. A module can have lower voltage than the other 27 modules. Neither of these occurrences would result in a "dead" traction battery as the battery can still produce power. However the traction battery ECU would log a DTC in either case because the traction battery is not safe to be used as-is and must be replaced.

When you say "battery terminals", I assume you are referring to the 12V battery. Low voltage across the 12V battery terminals typically is due to a discharged 12V battery. The battery is discharged because it is old and cannot hold a charge, or it is not being charged by the vehicle.

See my answer above. The fact that MG1 is spinning the engine is evidence that the traction battery is producing power. However that does not guarantee that the traction battery has no faults.

Use Mini VCI which is a Toyota Techstream clone. I have no idea how good your OBD-II code reader is. It might not report DTC logged by the traction battery ECU.

 

Thanks again Patrick. I was referring to the 12v terminals above. The battery is brand new as is the fusible link. I neglected to mention the 8.4 volts measured across the terminals was while car was in Ready mode. Also, please help a newbie with the meaning of DTC. Thank you for your patience.

 

DTC

 

DTC...Diagnostic Trouble Code...got it.

 

The inverter definitely needs to be replaced. I can’t say that the traction battery is definitely good or bad.

I suggest you put a charger on the 12V battery while you are waiting for the replacement inverter to arrive.

 

+1 to that, and the sooner the better. The longer the 12 V battery sits in that severely discharged state, the more damage is being done to it.

Charge it up now.

 

Thanks guys. I actually unhooked the battery after a few no starts.