Hello guys. I have a gen 2 Toyota Prius with 270,000 miles. It was a hot Dallas day yesterday and while wife was driving, red triangle came on. For some odd reason, she kept driving and about 3 - 4 miles from when the triangle first came on, the car died. No lights on instrument cluster, or MFD, nothing at all. The only functionality in the car was 12volt battery related. Central locking etc was working. There was burning smell in the engine compartment. Upon close inspection the smell was coming from close to the inverter and the inverter pump. Got the car towed yesterday and started my research today. First thing, AM2 fuse was blown. Replaced the AM2 fuse and the car turned on. Only after 15-30 seconds, car shut down again. Checked AM2 fuse to see that it was blown again. So that's where I stand at the moment. 15 Amp AM2 fuse is blowing out when replaced. From what I have learned so far, a shorted inverter pump (possibly inverter) could be the main culprit for AM2 blowing out so like that. So far the culprits seem to be the inverter pump, and possibly the inverter itself. I say inverter because burn smell seems to be coming from the inverter as well. (electronics possibly got fried?) Further suggestions welcome. So, where do I start? Clearly the AM2 is blowing so there is a short. Is there any relays to check that could be the culprit here? If I can't troubleshoot with certainty, I am thinking of pulling out the inverter pump, giving it 12 volt briefly and checking if shows signs of life and then go from there. Knowing that the car turns on briefly with a replaced AM2 fuse, is there anything else I can do here in terms of diagnosis? The replaced fuse gives no more than 15 seconds or so I believe. All help is appreciated in advance.
Your pump has shorted out so replace that before replacing the am2 fuse. Hopefully the new pump will solve your problems
Thank you for your reply JC. Can you recommend any place online where I can buy the pump cheap? I have heard of car-parts website here on this forum. I am in Dallas, TX
disconnect the pump replace the fuse if it blows again its not the pump.. odd are it is, call the dealer see if the will replace it under recall, if not they are cheap on e bay and easy to replace, just remove the headlight.. 15 min job, many youtube vids on it
Call Matt ASAP: Texas Prius Battery Replacement He does pump replacements among many other prius services in the DFW area and can come to your place (save a tow charge). Prices on his site. Great rep.
I had the same exact problem, the inverter pump was causing the AM2 fuse to blow because it was faulty.I changed the pump and replaced the AM2 fuse and no more issues.I looked at the old pump and all the electronics were fried at the bottom causing fuse to keep blowing.
Autonation Toyota Gulf Freeway in Houston sells discounted parts via the web. parts.com is a great place, and the prices are slightly lower than the dealer parts websites. The parts order is fulfilled by a Toyota dealer, typically out of state so you are not charged sales tax. As already stated, you can easily confirm that the inverter pump is the problem. Just unplug the wiring harness connector to the pump, located behind the driver's headlight. Then replace the AM2 fuse and see if you can keep the car READY for more than 15 seconds. If yes, then it is clear the pump is the culprit. There is a 95% chance that is the case anyway, but you can make your diagnosis 100% accurate by doing this.
Thanks for your input guys. A quick question: When I take out the pump, I would like the coolant to not leak. Any guidance as far as that is concerned? In theory I was thinking of stop-plugging both pipes the ones to and from the pipe so no coolant leakage occurs. That way I could test the thing without any extra steps and loss. What can you guys recommend? @Beachbummm I was thinking of doing the pump job without taking out the headlight. Is removing the headlight more common method, or doing it from the top? @fotomoto, thanks I will check it out. @Vince9022, thanks for the insight. I do have nasty burning smell coming from the engine compartment and I'm hoping it's NOT the inverter and hopefully I can get away with just the pump job.
@Patrick Wong Thank you for your valuable input regarding parts website and the pump verifiication process.
I go for the easy route so taking the head light out is better than fighting to move around other parts.might add 5 mins to the job. unless you have tiny hands that can get in there with tools to remove hose clamps, again many videos on youtube, watch a few and see what works best for you
I'm having same issue. AM2 was blown. Replaced and blew in 15 sec. Just disconnected the pump and fuse stopped blowing. However, car would not show ready and red triangle was still on. After a few minutes, decided to hit start. When I did, everything went dead again. AM2 fuse is ok - even put another new one in to verify. No dash lights again, just like before. Checked battery front and rear. Showing 12.8v front and back. Not sure what to try next.
Have you tried disconnecting the battery for a few minutes yet? Your going to lose the codes but it might help to get the car started. Also good to let the car sit for some time so the inverter can cool down.
Car isn't hot. Hasn't run for 3 days. I can't check the codes, so I hate to disconnect the battery in case it has to go to a shop. Any idea why it would not go to ready mode once I disconnected the inverter pump and got dash to come to life? Also why would hitting start if not ready bomb the system again?
New to this so forgive me if this is a duplicate. My reply is not showing up. So the car has been sitting at the shop since Saturday evening and has not started since I dropped it off. I did get the dash to come to life after disconnecting the pump and replacing the fuse, but it would not go to ready mode. Any idea why? Battery checked out. And then after I did hit start, now dash is dead again.
Hello, also new here, just a few years apart. Is there any chance that you or someone else has found out why the AM2 fuse still blows even with a new/disconnected pump? I am having the same issue, AM2 fuse blows .02 seconds after trying to start or get the Prius into accessory mode, even with pump disconnected. I tried to replace the power source controller with two different use junk yard ones I pulled, that did nothing.
