No READY. P1A15 error. Condenser charge timeout.

Mitsubishi i-MiEV Forum

Help Support Mitsubishi i-MiEV Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Hi, I'm a new one hear. Sorry for mistakes, my English isn't good. I want too shear you my litle experience in fixing this problem.
Ferst of all I deside not too use ad202. Desoldering small board I connect in "on branch" . As it's principal, it should translate voltage from Vin to vout as it is. Using oscilloscope I found it works correctly, output line was the same as input signal, but a little noicy. And in the same time, measering voltage with my appa105, I found mismatch, as all off you describe. Board working stable until Vpwr less than 9,5v. tl494 frec. I'd about 110khz. I change Ct down to 470p, and board start to translate a littel more to output, whan it get on it's input. Frec. is about 280khz. I find it as a good result.
Now, about some moments in pcb. 1 it's output with some noise. 2 the 2 power condensers on hv side. It's 1uf, but with the heating capasitence falls down to 300n!! 3 is possible problems in vias of the board.
Howdy LfL,
Welcome to the forum.
Thank you for sharing your experiments and findings, it is always helpful to compare results.

Would you say that just replacing the Ct capacitor was sufficient to repair your board? It has been tried but it seemed to be only a temporary fix and the problem returned.

The 2 capacitors toward the HV end are holding up the +5V and -5V supplies with reference to the HV-.
Do you think that they may be shorting internally and intermittently when they get warm?
I Don't know about is my fix temponary or not. We well found the answers some time later. The caps, I found, yes, it's them. My voltages was +6,8&-7,2. The reason I look at them is that they are was with damaged color of coverage. looks like they was overheated from inside. I just replace them to another, but it dose't take any effect to output of board.
Got a PM from a member with P1A15, and later some other codes:
Re: I'm asking for help
Sent: Mon Nov 07, 2022 12:19 pm
From: Mano16
Recipient: kiev

my chronology of the car problem is as follows. The car went into emergency mode while driving and the car with an exclamation mark started to light up. During diagnostics, it showed the code P1A15. As recommended, I replaced two capacitors, but it did not help, but the car always went into ready mode after turning on the key. So, as recommended, I added a resistor to the B1A chip.

After that, the car didn't get to ready. Of course, from the beginning of the fault, the car cannot be charged. So I canceled the added resistor and put the board in flooded state. I did diagnostics and it showed new faults P1A16, P1A26, P0AA1. Please advise me what to do.

So there may be multiple issues with this car:
1. it doesn't charge
2. it doesn't go to READY, P1A15
3. where ever the new codes point.

Concerning #1, check the fuse in the MCU located under the little access cover. If it is blown then there is likely damage inside the On-board Charger. There is a separate troubleshooting thread for the OBC.

Concerning #2, P1A15 is the subject of this entire thread.

Concerning #3,
P1A16 - This indicates that the bleed-off time for the big black capacitor in the MCU has taken longer than expected, so the EV-ECU throws this code. There are 2 paths for this discharge, one being a resistor in the upper plenum of the MCU and the other is a FET-driven discharge thru a large resistor in the bottom plenum. One possibility is that the connectors on the bottom control board were not fixed back into position properly after all the circuit mods mentioned in the PM.

P1A26 - this is a code set by the MCU; If the discharge command was received from the EV-ECU, and capacitor voltage is 42 V or more after 5 seconds or more have passed after the start of the smooth condenser discharge, then the MCU will set the diagnosis code No. P1A26.

P0AA1 - This indicates that the Main (+) HV Positive Contactor has welded its contacts together. The EV-ECU reports this code when the Contactors are commanded OFF, but voltage still exists on the big black capacitor. Hopefully this is related to the other codes due to an excessive long delay to bleed off the capacitor and not a real welding of the Main Contactor. Probable causes are listed as
Damaged wiring harness or connector(s)
Seizure of the charging contactor
Malfunction of the main battery
Malfunction of the EV-ECU

As we have seen on this forum over many cases, the root of all evil could be an old weak or worn out 12V starter battery which can cause a multitude of faults such as this. So that is the first thing to verify and rule out.

The only repair that i would recommend for the P1A15 would be to completely change out the hybrid board with a good board, or replace it completely with the isolation amplifier.

More detailed information is needed about the repair attempts to this car.
Additional information provided by PM:

Thank you very much for posting to the forum. Regarding your questions. The car is made in 2016 and has about 22,000 km. It is used daily, that is, when it is functional. Now it has been shut down for about 2 months due to malfunctions. As for my interventions, I did two, but without any positive effect. I replaced 2 capacitors on the charging board and added a 4 mO resistor to the B1A chip, but that made my condition worse. As for my focus, I am a high voltage electromechanic. However, I have a question. How could I measure the functionality of the positive and negative contactor without having to remove the traction battery? It is possible? And you asked about the service 12V battery. I connected a kind of stronger battery to it in parallel and the condition did not change. Thanks for your help Kiev

Did you check that all the little connectors in the bottom plenum of the MCU were plugged back in after you made and removed the 4 meg resistor mod?

There is a big silver bleed resistor mounted on the housing that connects to that board, and if it were not plugged in would cause a delay in pulling down the voltage when key is turned to OFF. That delay might be sensed and interpreted incorrectly as an issue with the contactor.

For troubleshooting the contactors there might be a couple of approaches: digital, using scantool and OBDII tools, or analog, using oscilloscope and voltmeter.
Massive thanks to this thread. Managed to make a repair on this 2012 C-Zero, by adding 2MegaOhm resistors to the voltage measurement board:

Let's see how temporary it is :)
from a PM about using the SIP version of AD202,

attached picture is a hybrid board with the pins numbered; use these pins coming off of the MCU control board for connecting to the AD202 SIP version pins [This ONLY applies to AD202 SIP]
[Edit: Some jumper wires need to be added to some of the AD202 SIP pins]

MCU 1(VH) connects to AD202 SIP pin 1 (+IN)
MCU 2(VL) connects to AD202 SIP pin 2 (Isolated Common)

Note: Add a Jumper wire between AD202 SIP pins 3 (-IN) and 4 (Feedback) [Jump 3 and 4]

MCU 3(Output) connects to AD202 SIP pin 38 (Output HI)
MCU 4(Common) connects to AD202 SIP pins 37 (Output LO) & 32 (Common Return)[Jump 37 and 32]
MCU 5(+15V Power) connects to AD202 SIP pin 31 (+15V Power)

This will be a "unity gain" configuration, i.e. the gain = 1, no amplification or attenuation. The Output voltage will equal the Input voltage, but they will be Isolated from each other and use separate Returns. If the signal needs to be adjusted, then resistors can be added to increase or decrease the gain.

Sorry I've not been on here for a while. I've ordered some more of the AD202KN PCBs, hopefully have them next week. My repair has so far done 7,500 miles and has never given a bit of bother.

A quick look at your layout seems okay. I wasn't able to ever find a source for the SIP version so I never did a layout. It would, however, make for a much neater repair if they could be sourced. Even the DIP version is going to be difficult to find by next year as it is going to be discontinued. :cry:
Hey ho

I tryed the setup I attach and it worked well.
Thanks for all the information to get to that point.
Hi everyone, first post.

About 6 months ago, after not using my i-MiEV for 2 months, it wouldn't start. I checked the codes and got a bunch of CAN-BUS errors and a consistent P1A15. I took the whole inverter board and put it in another i-MiEV and confirmed the board was the problem.

I copied the temporary hack of soldering in a 2 mega ohm resistor. I had to manually clear the P1A15 error and now my car starts consistently! :D


I have ordered a AD202KN for a more permanent fix but I would like to confirm my understanding of this temporary fix.

My ISA215 board must be giving wrong values for some reason. The board isolates high voltage from the battery to the inverter board. It uses a gain amplifier to do this.

It looks like we're putting the 2 mega ohm resistor in parallel with an existing 100k ohm resistor (on the back of the board). Calculating the parallel resistance gives me:

  (2m ohm * 100k ohm)/(2m ohm + 100k ohm)
= 200,000,000,000 ohm / 2,100,000 ohm
= 95,238 ohm

So we've lowered resistance by almost 5k ohm (5%). I think that means we've increased the gain in the amplifier, taking the input battery voltage to a higher output voltage.

I don't know how wrong my board originally was but this increase must be enough to kick it into the "acceptable" range. At different voltages, there might be more or less significant difference so I should check that I can consistently start the car at both full battery and empty - I haven't done this yet.

Considering my ISA215 board is giving faulty values (for some reason) then swapping to a AD202KN would probably be better. It sounds like the AD202KN board gives values which are slightly off (up to 3%, I think) but that should be fine.

Do we know why these ISA215 boards are failing?
I would like to thank everyone who has commented here, since reading this thread enabled me to fix my MIEV-s P1A15 error with 2 x 1 MO resistors in series. I considered soldering in a fine-adjustment potentiometer, but refrained for now. If there is no further degradation, I hope I don't have to revisit that part of the car - it was hard to reach.

The history of the car: its previous owner had let it stand idle for a VERY long time. I obtained the car in winter, the problem appeared in spring. At first the error could be cleared, but then it became permanent - and the pattern was the same, when the error was activated, contactors could no longer be heard clicking, and "Ready" state was not reached.

About the deeper reasons: no idea, I'm not good enough at electronics.

Is it true P1A15 shows up especially on cars that have been resting undriven for long time?

So whats the point? Corrosion (on cables)? Condensor deep unloading? Too weak 12V battery?
No i don't think that sitting is a factor; i have 3 mievs that had not been started or driven for over 4 years until about 2 weeks ago. The 12 V batteries were always kept charged and topped up during this time, and the pack was left at about 50 to 70% fully charged. They all started right up and drove without a hitch, and the pack voltage had not changed. i did not use the remote to lock the cars, just manually locked them (to reduce 12V drain due to the alarm system).

Seems to me that there is a component on the hybrid board which degrades and causes this issue; the factory had a MCU recall on certain build-months that i think was blamed on a bad batch of capacitors used on the hybrid board.

Ceramic Capacitors can get stressed and crack, or get leaky and degrade in value but still seem to be "working"--this is an intermittent sort of degradation where it sometimes works okay and sometimes not. Temperature and vibration would be a factor to consider.

A weak or worn out 12V battery can also cause this fault and plenty more. If you let the 12V get too low and sit for a long time, then you are asking for trouble in an EV.

The Analog Devices AD202 is a good solution to replace a defective hybrid board.
Isnt there space on the original hybrid board to replace the SMD capacitors by nice and good quality capacitors? The values are known?
For this entire thread i have created an INDEX post on page 1, post #4.

Hopefully to help find info quickly without the need to read the entire thing.

Open to suggestions to make it better.