While troubleshooting another problem, I learned that the 7.5 amp AM1 Hybrid System fuse is missing from the fuse box under the driver's dash. I bought it used and have been driving it this way for two years without any warning lights or indications something was amiss. I've been trying to get specific information on what this fuse actually does but I keep turning up zilch. I'm particularly curious about this because after I bought the car, I learned a shady dealership hobbled together a hybrid battery to replace the original and created a pretty dangerous situation. Luckily, and thankfully, I discovered the issue and replaced the battery but I'm thinking it may have been them that pulled the fuse. How can the car function without this fuse? Does anyone know? Thanks
Looking through the manual at all the references to AM1, about 1/3 of them are in the Smart Key System section. There are probably other systems whose wiring runs through this fuse, but just as a point of interest, does your car have a Smart Key and does it function like it should (i.e. can you open the door without removing your key from your pocket or purse and start the car without inserting the key in the key slot)?
I’m not sure there is supposed to be a fuse called “AM1” on your car. The Owner’s Manual (PDF) shows it on page 430, as item 14 in the list, but the Electrical Wiring Diagram for 2006 Prius cars (EM01R0U, more info) doesn’t: the illustration of the Driver Side J/B (junction block) shows no fuse in that position, and neither the System Circuit nor the Power Source sections mentions any fuse called “AM1.” For model year 2004, there were fuses called AM1 and AM2, feeding the AM1 and AM2 power supply inputs of the Power Source Control ECU, respectively. For model years 2005 and later, however, it seems that Toyota eliminated the AM1 fuse, leaving the AM1 and AM2 inputs both fed from the AM2 fuse. It’s likely that when this design change was made, the junction block and its label weren’t modified, probably to avoid the costs of creating and stocking another version of those parts. The ECU monitors these inputs, by the way, and if one were faulty, diagnostic trouble code B2271 would be stored.
It looks like Electroingenieur puzzled it out but I really appreciate you checking your manual. It was very kind of you!
Wow - that is some serious detective work! I'm seriously impressed and very grateful to have the answer. Thank you!
Yes that's correct my 07 manual shows where AM2 feeds 2 inputs of the Power Src IC. Pin12 is marked AM2 and Pin 33 is marked AM1. Both fed by good old AM2 fuse. So disregard empty AM1 fuse socket. Good eye Kristen you will need that down the road on this car lol........and both you AND Electro gets a I Like YOU!
2007 Prius has a 7.5 Amp AM1 fuse but no apparent AM2 fuse. Pin 14 is vacant on the fuse map and in the block under driver dash. Mine just suddenly had the symptoms of Invertor Coolant Pump failure, which had recall effective for 2008. Sudden black MFD and no dash lights except door ajar and security. Car will not go Ready. Pushing power button does nothing. 12V battery is fully charged and almost new. Which fuse powers the ICP on a 2007?
The AM2 fuse (15A) is in the underhood fuse box - marked on the right. Unplugging the connector to the left will disable the (likely shorted) inverter pump and prevent it from immediately popping a replacement fuse. The inverter pump has a finite lifespan and can fail - even if it was already replaced. A Toyota pump (from a dealer) can last around 10 years or 100k. Many aftermarket pumps have questionable reliability. Posted via the PriusChat mobile app.
