Posts: 791
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Troubleshooting and repair for On-board Charger (OBC), DC-DC Converter

Sat Jun 23, 2018 5:57 am

This thread will be used to document the technical information and any schematics or firmware available to help troubleshoot and repair the OBC/Converter. Post #2 has troubleshooting steps and an index of this thread that can hopefully be used as a guide to step through the process.

There seems to be many failures reported lately (last 6 months or so), so maybe it's time to figure out what is happening and come up with a lower cost solution. i started a photo album with pictures related to this box, also all my imgur pictures are found at:

List of links to user's recent failures [and successful REPAIRS] in reverse order, later near the top:

20. PM message, 10/2018, from tdigsi; looking for substitutes to replace the 680 and 220uF capacitors?
[EDIT: REPAIRED, replaced snubber caps and MCU fuse, now it is charging; going to replace HV caps anyway due to age and high mileage, est. >~5000 Hrs on caps.]

19. PM message, 9/2018, from Quixotix in Seattle; dealer says charrger is dead; recommended to request DTCs and open cover to inspect for damage, blown fuse, etc.

18. ChristopheFR, 9/2018, 2011 C-Zero in France, EVSE charging appears to start then quits, DCDC appears to work ok, Aux battery changed in 2015

17. skylogger#2, 9/2018, 2010 in Western Australia, blown snubber caps and MCU fuse, AC relay and precharge Rs

16. footswitch, 9/2018, 2012 not charging in Portugal, EVSE charging appears to start, then just quits, DCDC appears to work ok, still running with OEM Aux battery.

15. charliejuliet, 8/2018, failed charrger in Michigan UP, replaced with aftermarket DC/DC and Chademo charrger.

14. redcane, 8/2018, 2010 not fully charging in Australia (east coast), OBC was replaced with a 2015 unit under recall in January 2017.

13. skylogger, not charging in Western Australia, found blown surface mount capacitors.
[EDIT: SOLVED AND REPAIRED,8/12/2018, see picture of a twisted resistor causing open circuit on voltage monitoring]

12. beeline, 6/18, 2012 not charging, dealer estimates $4800+tax

11. mikedufty, 3/18, 2010 Australian model not charging fully in WA, charrger was replaced under recall. Dealer now pointing at EV-ECU as bad.

10. 1pk, intermittent charging level 1 and 2, found cracked bypass resistors at AC relay

9. Lic, 4/18, getting condenser timeout error P1A15, no main(+) contactor indication

8. jray3, 6/18, Mr. Bean dc converter not working, blown 20A fuse in the inverter

7. luvmymiev, 6/18, Category: i'll take bad charrgers for $4000--The question is:What did the dealer find?

6. electronpusher, 6/18, car not charging in New South Wales, blown snubber capacitors in the potted doghouse and fuse in the MCU.
[EDIT 10/7/2018: REPAIRED , replaced snubber caps and fuse and now it's working again, Good Job!]

5. Antaris, 3/18, service manager says the on board charging unit has failed.
[EDIT: REPLACED, Mits Canada replaced it for $800 Cdn]

4. fresnomiev, 3/16, dealer replaced charrger while troubleshooting by parts swapping, issue was MCU inverter.

3. pluto, 2/18, code 39 OBC, abnormal PFC voltage,

2. Sbess, 10/17,dealer says bad charrger

1. TorranceMiEV, not charging

iDriver, Nov 28, 2017, charrger fuse in MCU blown

Just for the historical record, mccluer had a very early report of charrger failure back in 2012

also DonDakin in 2013

also Malm, 3/2016

Here is a picture with the cover open, note scorch marks on inside cover and the full exposure of the tops of the electrolytic capacitors (credit to coulomb for pointing out this indicator of high temperatures):


Here are some wiring diagrams just to get started, will post a charrger schematic after it gets traced and drawn up.




Workshop Manual High Voltage 20 Amp MCU (aka Inverter) fuse links:

OBC Code 02 troubleshooting

How to access and replace the MCU fuse

see next post for troubleshooting notes
Last edited by kiev on Sun Oct 28, 2018 7:45 am, edited 73 times in total.
kiev = kenny's innovative electric vehicle

Posts: 791
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Troubleshooting Steps and Index

Sat Jun 23, 2018 5:57 am

Prevention ideas:

Don't disconnect AC power while charging--use the J1772 handle button or the remote for a controlled stop.

1. 12V Aux Battery Test
2. Check or Replace OBC and EV-ECU relays in the fuse box
3. Check OBC power supply


Step 1: Diagnostic Trouble Codes from EV-ECU concerning OBC DTC for OBC

Step 2: DTC for the DC/DC Converter DTC for DC/DC

Step 3: Internal Trouble Code List for OBC OBC trouble codes

Step 4: At this point the dealer has no real repair options but to sell you a new box, or you can find a used one and replace it--it will work without any VIN re-coding needed according to jray3, who did this himself, or you can open the box and inspect for missing/burnt parts and we can try to fix it here. or maybe you could send it to an expert in Australia (coulomb or skylogger), or in USA (piev or kiev). It's heavy, ~27 lbs.

Another option may be to altogether replace the OEM charrger and converter with an aftermarket solution, such as was done here by charliejuliet.


1. Thermal imaging during charging FLIR images

2. What's touching the heatsink? Bottom Board

3. What's inside it? Waffle Plate™

4. DC Buss Capacitors Swollen Caps and Precharge Simulation

Schematics and stuff:

1. AC Input Filter and Relay

2. Output Filter

3. Solder Pads to Waffle Plate

4. Low Voltage Supplies and Relay Drive description

5. Control (Top) Board Voltage Supplies discussion/measurements on page 9

6. Bottom Board AC detection circuit sketch

7. Output HV and Current sensing circuit sketches (related to skylogger's twisted sister resistor finding)

8. OBC connections and E-03 connector wiring

9. [url]ph[/url]

Notes of parts links:

Pictures and specs for blown snubber caps, Optional caps

for TAM ceramic resistors datasheet link,

PEC 20A 450VDC MCU fuse for MCU fuse spec sheet link,

and Fujitsu AC relay datasheet

Last edited by kiev on Sun Oct 28, 2018 4:42 am, edited 37 times in total.
kiev = kenny's innovative electric vehicle

Posts: 791
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Troubleshooting and repair for On-board Charger, DC-DC Converter

Sat Jun 23, 2018 6:45 am

Repair tips:

Quick, cheap and easy first,

Connectors make for quick and easy installation, but they are the most likely candidate for intermittent issues. The sliding contacts are prone to oxidation and dirt. Sometimes just disconnecting and cleaning the contacts with spray can of cleaner compound will provide a fix. With key OFF, just pull all the connectors on the EV-ECU and the BMU and clean all of them.
kiev = kenny's innovative electric vehicle

Posts: 1574
Joined: Tue Dec 06, 2011 1:05 am
Location: Tacoma area, WA
Contact: Website

Re: Troubleshooting and repair for On-board Charger, DC-DC Converter

Sat Jun 23, 2018 2:38 pm

Thx Kenny, I’ll add to #8 that both my DCDC and charger failed at the same time, fixed by replacing with a collision salvage unit.

Simply opening and reconnecting a wiring connector will renew the contact surface and break up corrosion, but a cleaning spray like DeOx-it could only help.

It appears that the 20 amp 400 VDC fuse I blew is both the charging output and the DCDC input, would you agree? That makes me suspect only one of those two actually failed.
2012 i-SE "MR BEAN" 94,000 miles
2000 Mazda Miata EV, 78 kW, 17 kWh
1983 Grumman Kurbwatt EV,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet

Posts: 791
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Troubleshooting and repair for On-board Charger, DC-DC Converter

Sat Jun 30, 2018 8:50 am

the list has nearly doubled in the last week! High temperatures to blame?
kiev = kenny's innovative electric vehicle

Posts: 363
Joined: Wed Apr 29, 2015 10:26 am
Location: Laurel, MD
Contact: Website

Re: Troubleshooting and repair for On-board Charger, DC-DC Converter

Sat Jun 30, 2018 10:35 am

Not to derail the thread, but if we're contemplating replacing the charger, it would be... interesting... if we could upgrade it, to a faster rate, at the same time. Conceivable? Impractical?

Posts: 89
Joined: Tue Jul 05, 2016 5:02 pm
Location: Toronto Canada

Re: Troubleshooting and repair for On-board Charger, DC-DC Converter

Sat Jun 30, 2018 2:11 pm

I bought my 2012 used with 50,000 km (30,000 miles) on it so I don't know its history.

For the past 2 years I have been charging it only on 120 V L1 (8 amperes?).

I was curious what rate the cars with charger failures have primarily been charged with.

Posts: 25
Joined: Tue Apr 05, 2016 1:04 am
Location: Western Australia

Re: Troubleshooting and repair for On-board Charger, DC-DC Converter

Sat Jun 30, 2018 7:48 pm

A few of them are from Australia where it is winter so probably not high temperature. Mine went in May, which was unusually warm this year (30 C) but still not summer temps.
Australian ones charge at 240v so more than the US L1.
DC fast chrging doesn:'t use the onboard charger so should not be a factor.

Posts: 292
Joined: Fri Jul 27, 2012 7:35 am
Location: Winter Garden, FL

Re: Troubleshooting and repair for On-board Charger, DC-DC Converter

Sat Jun 30, 2018 11:20 pm

RobertC wrote:A week ago one of my 2012's would not charge. I connected Canion and it showed that all 88 cells were the same voltage, ruling out a bad battery pack. When I connected the EVSE the fan would start on the battery pack as usual, and the EVSE would indicate charging, but would shut off after a few seconds. I connected another EVSE and had the same results, ruling out a bad EVSE. I suspected a bad On Board Charger. The local Mitsubishi dealer (Sport Mitsubishi in Orlando - I've had several great experiences with them) agreed, and replaced the On Board Charger (over $4,000 for the part, over $5,000 with labor) under warranty and we are back in business. I dropped the car off Monday afternoon, and picked it up Saturday morning, and they also performed the latest recall and installed new tires. I asked Sport Mitsubishi if they offered an extended warranty and was told that they did not. Our 5 year 60,000 mile power train warranty expires in May of this year for those of us who bought the i-MiEV when it was rolled out nationally in May of 2012. I repair electronics for a living now, so if the On Board Charger fails after the warranty expires I'll have a go at repairing it myself or I'll try to buy a used one because I'm not paying over $4,000 for a new one.

My On Board Charger failed on my lower mileage (30,000 miles) i-MiEV “Purple” April 2017 and was replaced under warranty. I posted my concerns at the time but did not receive any feedback on this forum. I recently sold my other 56,000 mile i-MiEV “Silver” and was glad the On Board Charger had not failed yet since it was out of warranty. I also estimate the i-MiEV that I sold had between 60-70% of its original battery capacity.
”Blue” - 2018 Kinetic Blue Chevy Bolt Premier with QC - 5/13/18
“Red” - 2017 Cajun Red Chevy Bolt LT with QC - 3/30/2018
"Purple" - 2012 Raspberry Metallic ES with QC - 4/10/2013

Posts: 791
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Step 3: Internal Diagnostic Codes for OBC

Tue Jul 03, 2018 4:41 am

After reading the EV-ECU DTCs, the dealer should use the MUT3 to read down into the Data List from the OBC to get the Internal Diagnostic Code from the OBC / DC Converter box. This gives specific circuit malfunction information that can help give us some idea of which circuits to investigate.

For most of these, the first time it occurs, the OBC will store the code. If it happens again at the next charging, then it throws the code up to the EV-EVU that a malfunction has occurred. This should cause the trouble light on dash to be lit. A few are so serious that a malfunction is indicated at the first instance.
    01Output voltage abnormal
    02 Load connection abnormal (main battery not connected)
    03 Output current abnormal
    04 Control power supply voltage abnormal
    06 AC input voltage abnormal
    11 Voltage command abnormal
    12 Current command abnormal
    13 EV-ECU lost
    15 Power factor correction (PFC) circuit temperature abnormal
    16 Temperature in increasing voltage area abnormal
    17 Inside ambient temperature abnormal (boost circuit rectifier temperature abnormal)
    26 Charging current limited (temperature increase)
    27 AC input current abnormal
    28 EEPROM abnormal
    29 Pilot signal abnormal
    30 Electric motor circuit abnormal
    31 Temperature in increasing voltage area abnormal 2
    32 Charging current limited (input voltage decrease)
    33 ROM/RAM abnormal
    35 AD conversion module abnormal
    39 Power factor correction (PFC) circuit output voltage abnormal
    41 Input current sensor 0 point abnormal
    42 Output current sensor 0 point abnormal
    43 Inverter overcurrent abnormal
    44 Rectification overvoltage abnormal
    45 Rectification overcurrent abnormal
Last edited by kiev on Sun Sep 02, 2018 8:33 am, edited 5 times in total.
kiev = kenny's innovative electric vehicle

Return to “Batteries and Battery Management”