Reviving Non-Op UK Auction Sibling

Easycarex said:

-no error codes with 12 volt connected and high voltage unplugged
Error message with high voltage plugged in and 12 volt disconnected

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Fished this reply out of the middle of the quote block. Now, when you didn't get an error code with the HV disconnected, did the car go READY? If so, I'd say the heating element and/or controller is shorted.

Still no ready ping.
Mechanic will try the 2 100 k ohm resistors in pins 6,7and 8.

Can't offer any help but wish you well. It's this kind if nonsense that scares me. Really....why should a heater fault immobilise a car ? Ridiculous

The P1A15 code is thrown when it takes too long to charge up the voltage (to 220V or more) of the big capacitor located above the FETs in the bottom of the EMCU (electric motor control unit, aka drive inverter). The capacitor could be leaky or the precharge resistor could be open circuit or too high resistance, or there could be some extra load on the pack (like the heater is shorted or commanded ON), which prevents the precharge from reaching either the voltage or time requirement. Step 7 checks to measure this voltage.

Of course before getting to step 7, did the mechanic run step 3, check main fuse? Removal of several cover panels is required to get access to the main fuse plate on the bottom of the pack, but once there, a check of the heater and the A/C fuses could be done also.

But a quick way to check both the fuse and the voltage is to pull the top cover plate off the motor controller and measure the voltage directly at the input terminals with a voltmeter.

If there is no voltage, then the main fuse is suspect. If the voltage rise is slow or below the expected 220V, then the EMCU is suspect.

On a more basic level, do you know that the pack is good--what does the 'fuel' gauge and range-remaining read when key is switched to 'ON' ? Does the car take a charge when you plug in the charging cable?

Covers off mcu, all looks good, fuses all checked.
Pack voltage OK, shows 70 miles range, State of charge weird- initially shows 3 bars then slowly lights up all 16 one bar after the next.
Would not take a charge from a ChaDeMo.

Easycarex said:

... State of charge weird- initially shows 3 bars then slowly lights up all 16 one bar after the next.
Would not take a charge from a ChaDeMo.

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If the pack is full then it can't take a charge from chademo, but will it charge with the on-board charger from the AC port?

The slow 3 to 16 bars effect is a clue to why it won't go to Ready mode. But what could be causing this? The P1A15 code is thrown because of this slow ramp up in voltage. The flowchart indicates to replace either the MCU or the Main Pack if it has passed all the previous steps. Not sure how anything pointed to the heater from that code.

But consider that this is not a regular car that just quit all of a sudden--it sounds like a salvage or non-running car with uncertain history that someone messed around with trying to get it going and then bailed out. So all bets are off--there is no telling what they may have tried, disconnected or jumpered around in the harness in their effort. The normal codes and troubleshooting flowchart are for an as-delivered car, not for one that has been tampered.

i hope that disconnecting the HV to the heater and the 100 kOhm trick works...

I've seen my car do the growing bars a few times. Usually, it was starting the car immediately after unplugging from a level 2 station mid-charge.

Richard the Mitsubishi mechanic has tried the resistors, still no ready ping.
He is in the process of removing my imiev's heater unit and plugging it into the C0.
Need to get in help from Stan if it turns out to be the faulty heater stopping the final HV relay working

Somehow i'm not surprised it didn't work--the flowchart indicates it is either the motor control unit or the pack.

Richard has tried my imiev with the heater disconnected and it gives the ready ping.
Undeterred he plugged in my heater into the Citroen, with predictable zero result.
Seems imiev forum knows more about the root of the problem than both Mitsubishi Technical, and Citroen Glasgow (who initially diagnosed a heater fault)..
Going to try swapping the inverter over next.

At least you have 2 cars to play with and can swap out parts, and by doing all this hopefully someone will learn something useful and gets some experience to help out in the few-chur.

I seem to remember some discussion about the inteligent parts of the imiev being programmed with the vin number. I dont know if i understood this correctly but my understanding was that it was to prevent parts swapping. I.e. You would have to install a part and then program it with the mut 3 to give it the right vin number. Then it would work.

If this is right then you may not be able to swap a part like the charger or the mcu on two cars and have it work.

Hopefully this is not the case but its something to keep in mind as you try to narrow down what is wrong with your imiev.


Don......

Moderator can you change the title of this thread?
I feel we have ruled out the heater being the cause of the failure.
Most lightly cause, a fault in the motor control unit; should know this week.

Easycarex, many of us have been following your trials and the excellent troubleshooting suggestions, especially by kiev and DonDakin. When you do finally get the car running, please, please, do let us know what got the car working again. Hope you approve of the changed title

Thanks for the new title.
Really appreciate your, Kiev and DonDakin's help, the online manual posted has given me hope of finding the cause for the P1A15 error code

Did the mechanic measure the battery's terminal voltage directly when attempting to start the car? The voltage may be good inside the pack (as reported by the BMU), but it's no good if it can't get out. Like kiev, I'm thinking that there's something wrong with the MCU, the condenser, or the pre-charge resistor.

Also, has the service plug been checked to make sure it is properly seated? This is found under the driver's seat (which needs removed to gain access to the service plug).

Does the car throw a code or have to be reset by MUT if you remove the front seat? driver's or passenger's

As long as you don't turn the key on, I think you're okay. For added insurance, disconnect the 12 volt battery first. If anything, the airbag light will come on, which requires a clear from the MUT.

Richard has been given a form to measure voltage and resistance at multiple points in the HV circuits, which Mitsubishi technical in Japan want to see, unfortunately he has gone on Holliday for 10 days.
Mitsubishi are under the impression it's my imiev with the fault. Can't emagine getting this quality of service from a Citroen dealer.
Relieved to get my imiev back from the garage.
It goes to ready with both the heater and air con unplugged.

Just an update.
Still waiting for Mitsubishi Japan to say what's wrong, they have had all the reading's from the battery pack, suspect resistor was OK.
Richard was checking all the plugs for corrosion, when he plugged everything back together he found the car would come to ready!
He drove it and everything was working fine, however the next day it would not come to ready.
Looks like it's the capacitor or the final contactor.