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

Posted: Tue Sep 29, 2020 5:17 pm
by dweaver
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'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.

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

Posted: Wed Sep 30, 2020 6:45 am
by kiev
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.

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

Posted: Wed Sep 30, 2020 9:53 am
by dweaver
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.

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

Posted: Wed Sep 30, 2020 10:50 am
by kiev
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 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.

Hi kiev....I can see they had the small cover off the MCU.......

Posted: Wed Sep 30, 2020 12:48 pm
by dweaver
I removed it. Checked for current. Pulled the fuse. It's good. Put it all back.
There's a small box below the 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.

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

Posted: Wed Sep 30, 2020 1:07 pm
by kiev
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?

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

Posted: Wed Sep 30, 2020 1:42 pm
by dweaver
Fredericksburg, Va.

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

Posted: Thu Oct 01, 2020 5:30 am
by kiev
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.
It might help give you some idea about troubleshooting the problem.

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

Posted: Thu Oct 01, 2020 1:21 pm
by dweaver
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 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 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!

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

Posted: Thu Oct 01, 2020 4:05 pm
by kiev
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.