Car died while driving with lots of km left.

[SailACat]

Hi, while driving on the highway the other day, the car just died. Had it towed back home and tried to charge but the charger clicked twice and stopped charging as if the battery was full.
I checked my 12 volt batteri and it had a low voltage. After charging the 12 volt batteri with a separate charger, the car starts again and I can drive but I have error messages in the display. I still cannot charge the main batteri.
I do not have any diagnostic tools so I wonder if the symptoms above could indicate a faulty OBC?
The fact that I can drive the car after charging the 12 volt battery, does it mean that I can drive the car but the 12 volt will run low with a faulty OBC and the car will eventually stop as it did the first time?

The first picture below is just after having started the car, the second picture is a minute later.

Any help is appreciated (to install a new OBC at the Mitsubishi outlet in Norway is over 6000 euros)

Rolf

 

[kiev]

Howdy Rolf, Sorry to hear of your problems.

An old, weak or worn out and depleted 12V
auxiliary battery can cause a multitude of faults such as you have experienced.

Do you have a voltmeter that you could use to measure the actual voltage on the "starter" battery up front under the hood?

If so get four readings: when the car is OFF, and with key at ACC, and ON positions, and then when car is in READY.

If the car goes to READY, then the main contactors are likely Okay/ not damaged.

If the battery voltage goes up to 14.4 Volts or so when in READY, then the OBC fuse located in the MCU is not blown, which is a good sign for the Output stage section of the OBC. And the DCDC Converter located in the bottom plenum of the OBC is working Okay.

The High Voltage Error ( yellow !) would prevent OBC charging, as would damage on the AC Input section, but first the 12V system voltage issue must be resolved.

If there is a big drop between the OFF voltage and the ACC or ON position voltages, then the battery is suspect. It needs to be fully charged and tested to verify it is good and strong before additional diagnostics can be done.

 

[SailACat]

Thanks for your tips.

OFF: 12,6
ACC: 12,3
ON: 12,2
Ready: 12,1 and I can drive the car

Decimal values may be a little off since I used an analogue voltmeter.

The battery is brand new but has been idle for two week and it has been quite cold lately.

 

[kiev]

OFF: 12,6
ACC: 12,3
ON: 12,2
Ready: 12,1 and I can drive the car

That helps and shows that the DCDC is not working, likely due to a blown fuse in the MCU (motor control unit aka drive inverter for the EV motor).

This fuse gets blown when the snubber capacitors in the OBC fail, usually explosively.

There are many examples and pictures of this repair in the OBC troubleshooting and repair thread.

The fuse could be replaced and the 12V would get charged from the DCDC, but unless you have access to Chademo charging for the Pack, your remaining driving is limited to whatever is now left.

Keep the 12V fully charged with an external charger.

 

[SailACat]

Thanks, I have to find som links and youtube videos to get a grasp of what you mean. Will probably have some more questions later.

Rolf

 

[SailACat]

Talked to the repair shop today and on my question if I could drive the car the 30 km to get there (I have 76km left and a full 12 volt batteri) he said no.
The fact that I can drive the car in my driveway is because it runs of the 12 volt battery. I found this strange.

Can anyone confirm that?

 

[kiev]

The 12V battery is providing the power for the main contactors and relays and all the ECUs, lights, fans, coolant pump, brake vacuum pump, etc. Probably 10 to 20 Amps.

If the DCDC Converter can't operate to supply this power and recharge the 12V battery (because the fuse in the MCU is blown), then yes the 12V battery will be drained and it may even fail while trying to drive 30km.

If you replaced the fuse first, then you could make the drive with no problem.

20A fuse for 13 euro

What repair service do you expect the shop to do for you? Will they replace your OBC with a used one, or repair the damage in your unit?

i had this exact situation happen to me, where my fuse was blown and i needed to drive to the dealership to replace my OBC under warranty. i replaced my fuse with a jumper wire just to make the trip. The dealer gave it back to me after they made the repairs.

 

[jray3]

Rolf, greetings from a catamaran sailor and former resident of Stavanger! Be sure to capture the trouble codes before any well-meaning mechanic clears them. Replacing the OBC with a salvaged unit is only a 90 minute job (but twice that time the first time you do it!). You could also make the drive with a jump pack or second 12V battery, I'd just input it through the "cigarette lighter" outlet if your car has one. I'd also try the car on a CHAdeMO charger if you can. The cars will often still DCFC after an OBC failure, but not always.

 

[pbui19]

I would put a charger on the 12v pronto, especially in the cold temperature. It is not getting charge by the iMiev. By the way, what year is your iMiev ?

Worked briefly in Stavanger, beautiful fjords

 

[SailACat]

My iMiev is 2012 with a 2013 battery. The latter was replaced under warranty.

As for Fjords, we do have a couple and the Coastline from Stavanger to Trondheim is quite spectacular but the Lofoten Islands in the summer when the weather is nice is also a good option for scenic tours.

Could not get the fuse from Farnell but might have som luck here:
https://no.mouser.com/c/circuit-pro...ze / group=HEV Fuse&voltage rating dc=450 VDC

 

[michael8554]

Lofoten Islands in the summer .

 

[SailACat]

My iMiev is 2012 with a 2013 battery. The latter was replaced under warranty.

As for Fjords, we do have a couple and the Coastline from Stavanger to Trondheim is quite spectacular but the Lofoten Islands in the summer when the weather is nice is also a good option for scenic tours.

Could not get the fuse from Farnell but might have som luck here:
https://no.mouser.com/c/circuit-protection/fuses/automotive-fuses/?current rating=20 A&fuse size / group=HEV Fuse&voltage rating dc=450 VDC

Picked up a fuse from the local Mitsubishi dealer yesterday and the capacitors from a guy in Norway who had bought several when his OBC died.
So now I have to wait for nicer weather before I can start the repair.

I did notice though that my OBC looks different on the outside compared to the ones I have seen on youtube. Does it look the same inside?

 

[kiev]

Your OBC looks to be the correct version for the model year. See the OBC troubleshooting thread for internal pictures and repair tips,
https://myimiev.com/threads/the-troubleshooting-and-repair-for-on-board-charger-obc-thread.4079/