Hi everyone....have two 2012 I-Mievs.....need help....

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dweaver

Active member
Joined
Sep 29, 2020
Messages
36
we bought both new.
Last year....we had to have the main battery system replaced under warranty on Silver.
Days ago Silver died.....wouldn't start. Had it towed to dealer.
They claim....it's the ac to dc inverter. Cost....$4000 for the part and hundreds for labor.
I had it towed back home.
I don't want to put that much money in it.
I ran across your forum....noticed the extended warranty from Sept. 2019 that others had posted,
I dug mine out of the glove box.
The battery warning light and the power unit light were on.
Dealer said no codes were set.
Are we covered under warranty? Is the ac to dc inverter the same thing as the MCU?
Any help is appreciated.
I plan on calling Mitsubishi Motors if necessary.
Thanks.
Dale
 
Sorry to hear of your problem.

It may be that the AC to DC Inverter is the On-Board Chargger, which converts AC from the wall outlet when you plug in to charge the car.

The MCU converts DC from the Main Pack into a 3-phase AC to drive the electric traction motor.

There should be Diagnostic Trouble Codes stored in the EV-ECU for any fault situation, and usually dash error lights glowing.

There was a limited recall campaign for some of the MCU units, and the OBC warranty was extended to 10-years to match the main pack extension.

What is the status and condition of the little 12V auxillary battery under the front hood? Is it the original from 2012 in both cars? A weak, old or worn out aux battery can cause the car to not start.
 
Hi kiev, thanks for the response. I talked to Mitsubishi Motors and the dealer this morning.
Apparently, the MCU is not under the extended warranty. Motor Control Unit. Only the OBC.
Dealer states, no codes set, ac to dc inverter is bad in the MCU.
12V battery is good, new last year. Just for kicks, put a jump on it.....nothing.
Just two lights on the dash....battery and high voltage light.
I'm pretty sure the fuse is blown in the MCU. Dealer wants to replace the whole box for 4700.
What would you do?
How do you find a fuse?
How much has to be disconnected to replace the fuse?
Apparently the dealers won't open these boxes.
Thanks.
 
there has to be codes for them to know and tell you what was failed. maybe they have not much experience with these cars, which is not surprising there are few of them and they rarely fail.

There is a thread on here about Troubleshooting the OBC and DCDC converter which has a link to a picture of the http://myimiev.com/forum/viewtopic.php?f=22&t=4310&hilit=MCU+fuse#p39079 MCU and the fuse in post #2 index. This is with the entire cover removed, but it is not necessary to access the fuse.

It is very easy to check and there is no High Voltage that needs to be disconnected. Make sure the key is out of the ignition switch. Lay the rear seats forward, then In the rear trunk under the carpet is the engine compartment cover plate with 4 wingnut screws. Remove (an reinstall) in order 1-4 starting at the front left corner, right, rear left, right, then flip the lid forward on the pivot.

There you will see the OBC on the left and MCU on the right. There is a little cover plate on the MCU and the fuse is under that plate, you will need a Torx driver to remove one of the cover screws. Use a voltmeter to check first whether there is any voltage between the two buss bars on the far right, there should be none; then check for continuity across the fuse, if there is none then the fuse has blown.

Usually if the MCU fuse has blown then there is a fault in the OBC. That fuse is located in the MCU, but it's function is to protect the wiring of the OBC.
 
I removed it. Checked for current. Pulled the fuse. It's good. Put it all back.
There's a small box below the MCU....top right and down. I wonder if that is the ac to dc invertor. Probably is.
I can't see putting this much money into Silver. I'll probably junk it or keep for parts.
It's a shame really, new main battery system under warranty last year, 4 new tires this year, new 12V battery last year, 24,500 miles.
;-(
Thanks for the help.
 
Don't give up too easy or too soon. We have tools to read the codes even if the dealer won't or won't tell you what they are. The DTCs all have troubleshooting steps in the Factory Service Manual to find the culprit.

Where are you located?
 
Do you have a volt meter to measure the actual voltage of the 12V aux battery while the key is OFF and when it is turned to ON, and also monitor the droop that occurs when turned to READY?

Do you hear the normal clicking and clacking of the relays and main contactors in the pack when key turned to READY?

There is a thread about the DTC P1A15 in which the car won't start; several folks have repaired/replaced the MCU.
http://myimiev.com/forum/viewtopic.php?f=23&t=4225#p38258
It might help give you some idea about troubleshooting the problem.
 
Hi Kiev,
No sounds when I turn key to READY.....nothing.
I tried to get a code reader from Autozone.....they don't even have one that works on these cars.
My neighbor and I tried his reader.....it kept getting hung up on #3.....transmission switch something if I remember right.
I did read the 12V battery a couple of days ago....12.4V. It's new from the dealer last year.
It is weird.....dealer said no codes set.
I'm so frustrated with this thing....I'm going to push it out back into the field and shoot it!
 
Put a chargger on your 12V aux battery, a new strong battery should be 12.8 to 13.8, at 12.4 you are at less than 75% capacity open circuit. and when you turn the key to ON you could drop to below 9 or 10V. A lead acid must be stored at 100% or the plates will become sulfated and can be permanently degraded and damaged.

Put the key in and turn to ON, then look at the dash to see what gear is showing by the fuel gauge. If it doesn't read as P, then the car won't start or do anything when you turn the key.

So with the Key at ON, press the brake and exercise the shift lever all the way thru the gates/gears from the top gate to the bottom and back. Do this several times and notice if there is any stiffness or grabby feeling in the lever, and track that the dash is reading the same as the gate position. Put it back into the top gate, P, and verify that the dash gauge also indicates a P. If so they try to start again and see if there is any change.

If the lever felt stiff or grabby, then you may need to lubricate the shift cable back under the car on the left side of the gearbox. Considering the age of the car it is likely in need of lubrication anyway.

i suspect that the gear position sensor or the lever is somehow not fully seated in the correct position and this is preventing the car to start; the dealer didn't read any codes because there is nothing wrong with the car.
 
Thanks kiev,

I ran it through the gears, looks fine on the dash through all of the letters. Everything still the same, won't start....same battery light and high voltage light.

Interesting though, after I had it towed back home from the dealer a few days ago, I had noticed after popping the hood, the plastic nut was missing off the battery plastic cover. I called the dealer, he spoke to the tech. The tech said he never had the front hood open, never had to open it, and never touched the 12V battery. Really?
So, after you asked me previously about checking the 12V charge, I found the plastic nut on the cowl under the front windshield....just laying there. Someone had it off.

Also, the dealer informed me a few days ago with estimate that engineers at Mitsubishi Motors told the tech by phone, since a code didn't set, that it was the ac to dc inverter. Really?
Does any of this sound right?
Also, isn't the ac to dc inverter in the OBC? Which is covered under the extended warranty?

Anyway, it's raining right now. First thing tomorrow in daylight I'll check the static 12V battery reading in Raspberry for comparison. Then charge the Silver 12V battery up and then see what happens.

Thanks again for the time and help.
 
Sounds like some basic electrical troubleshooting is needed, such as checking all the fuses and relays related to the Starting circuit and the EV-ECU, which is the master control unit for the MCU, OBC, BMU, the Pack, etc. If fuse #7 or #11 is blown then that keeps many systems off.

Also there are some fusible links on the aux battery positive terminal; a blown link would be a no-start issue, and maybe somebody was looking around in there to check those links?

If the dash lights up with the key at ON, but nothing happens when starting...i'm thinking there is no 12V power getting to something in the starting circuits. The MCU is referred to as an Inverter, for example in this circuit diagram:
http://mmc-manuals.ru/manuals/i-miev/online/Service_Manual/2012/index_M1.htm
 
it was reading 12.35 before charging....didn't matter. Checked fuses all over. No luck. I guess it's all worth checking before spending a bunch of money.
Maybe the MCU is the right call.
I would try a used one....but not putting $4000 into this for a new one. I don't have the equipment either to put my VIN in an MCU.
I agree kiev.....there might be no 12V getting to the starting circuits for some reason.
And, car won't charge main battery system either when hooked up. No start up sounds of cooling fluid pump or anything.
Car shows there is a 68 mile charge in the system.
Not sure what else to try except a used MCU.
Thanks for the help.
 
Howdy Dale,

That was just their guess about needing an MCU. Without some real DTC codes it was just a guess based upon. nothing.

My guesses are based upon many hours tracing circuits and troubleshooting failed OBCs, DCDC and MCUs.

It is likely that the EV-ECU is not getting 12V power, which would cause the car to not go to READY, and would cause no DTC codes to show up. If the HV warning light shows up on the dash (Car with !), then there is definitely a DTC to indicate what is wrong with the car. Even if the MCU were failed, there should still be 12V power getting to the rest of the system to display the codes--that is why i posted the link to the wiring diagram.

i can post more wiring diagrams of stuff to check if you are up to it. If you have given up then let me know.

kenny
 
I tried the Innova Car Scan Pro.....it couldn't communicate. The guys at Autozone were puzzled.

I can try another code reader....which one will work with this car?

This all began after my wife returned from a grocery store. Stopped, parked, and shut it off. Went to go again and nothing.

And.....I forgot. Over the last week while trying to start it.....the brake light will come on. WTH? Why would that happen?

Thanks for any input.

I can check some things. I'm not real good with electronics and don't have good electronic testing equipment. I'm 62. :lol:
 
My problem sounds identical to this guys....

"I-miev does not start. Need help" from Jan. 20th 2019.

So....he cleared the codes and it fixed everything?
 
Dale, I recommend the iCarsoft i909 as a fine scan tool that can read and clear the codes from an i-MiEV. It costs $104 on Amazon. The tool is simple, but since it only has 6 buttons, is a bit slow and clunky to use (CaniOn is much better for individual cell voltages and temperature readings)- and the menus are somewhat awkward Japenglish... Keep plugging away and you'll solve the issues. When I was able to diagnose and fix the failed onboard charger for under $500 while dealers were demanding $4200, you can bet that was good for some spousal currency! :p
 
Thank you all. I ordered the icarsoft i909. Might have it by Thursday. I would probably end up needing it for Raspberry anyway in the future.

Is it possible that the dealer is just incompetent, considering they only sold maybe 4 of these cars since 2012? :lol: We live in commuter town to D.C.. The Chevy dealer here won't even carry and sell a Bolt. They are so backward.

I would try checking the 12V battery under load, but it's new, dated 1/18 and has full charge, and it appears there is no draw on it anyway when I try to go to ready. I'm not ignoring your ideas and suggestions kiev, I really appreciate them, just based on my experiences with 12V batteries, it's not that. I could just switch 12V batteries from Raspberry to Silver and see what happens. At this point, I'll just wait for the i909 and see what happens then.

Thanks,
Dale
 
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