kiev
Posts: 1605
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Not able to drive. P1A15 error.

Sun May 02, 2021 4:46 am

Sounds like a good approach to me, especially considering all the labor/shop time expense to inspect, clean and verify electrical connections and wiring.
kiev = kenny's innovative electric vehicle

Gencis
Posts: 69
Joined: Fri May 04, 2018 2:45 am

Re: Not able to drive. P1A15 error.

Thu May 06, 2021 8:02 am

Image
MCU board is on the right or on the left if looking from the rear of the car?
Last edited by Gencis on Mon May 10, 2021 7:55 pm, edited 1 time in total.

kiev
Posts: 1605
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Not able to drive. P1A15 error.

Thu May 06, 2021 10:06 am

It is on the right hand side.

You can verify this by lifting the carpet and lid of the rear compartment and reading the labels on the boxes. The left hand box is the OBC/DCDC made by Nichicon. And the right hand box is the MCU made by Meiden.
kiev = kenny's innovative electric vehicle

Gencis
Posts: 69
Joined: Fri May 04, 2018 2:45 am

Re: Not able to drive. P1A15 error.

Thu May 06, 2021 10:32 am

To Kiev: Thank you.
And if I understood from the forum correctly, the MCU board is accessible from the bottom?

kiev
Posts: 1605
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Not able to drive. P1A15 error.

Thu May 06, 2021 10:41 am

The control board for the MCU is in the bottom plenum, but i don't know if it is easily accessible from below while installed in the car; it may be easy but i have only worked on these on a workbench after the MCU was removed from the car. But removal has it's own set of issues regarding bleeding air from the coolant lines.

If working on it while in the car, be sure to disconnect the 2 low voltage connectors so no 12V power on the board; and make sure car is off and not charging don't want any HV either.
kiev = kenny's innovative electric vehicle

Phximiev
Posts: 1241
Joined: Thu Jan 15, 2015 7:25 pm
Location: Phoenix

Re: Not able to drive. P1A15 error.

Fri May 07, 2021 8:49 am

I thought this was an interesting read and, given the technical discussions on the forum, applicable: https://m.slashdot.org/story/385140
2012 iMIEV ES
2014 Chevy Volt

Gencis
Posts: 69
Joined: Fri May 04, 2018 2:45 am

Re: Not able to drive. P1A15 error.

Sat May 08, 2021 8:57 am

So I have finally taken MCU unit out of the car.
Inside there was some aluminum corrosion at the openings. There was almost no sealant on the cover. It opened very easily.
Image

Inside was some specific smell of electronics. For me, the board has no clear visible damage/loose/burned parts. But I have almost no knowledge of electronics, so all this is a little bit tricky for me.

Image

And from forums, I understand that part B21 is responsible for the voltage calculation. Somewhere here is soldering resistors for battery voltage calculation.
Image

What parts should I check when MCU is out of the car?

kiev
Posts: 1605
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Not able to drive. P1A15 error.

Sun May 09, 2021 5:25 am

Check the resistance of all the little blue resistors and the resistance from the input posts (VH and VL) to the via near pins 2 and 3 of the op amp on the ISA 215-hybrid board. VH to pin 2 ~100k and VL to pin 3 ~50k. Plus those 3 ceramic capacitors are suspect but would need to be removed from the board to check, then might as well replace them with fresh new ones. An electronics repair shop should be able to check all this for you especially with a schematic.
There is a schematic in this post from page 2 of the P1A15 thread started by Lic. http://myimiev.com/forum/viewtopic.php?f=23&t=4225&start=10#p39208

If no values are found out of spec, then i suspect the hybrid board, but where to buy one? Some folks have tried replacing just the op amp chip marked with date code B21 on your board. B26 on mine.

Bezzeb swapped the op amp
yes, after replacement AD8677 the car started up
but not for long.
As I understand it, the problem is in the capacitors, which, after heating, give an error again

Your P1A15 was an intermittent fault that has progressed to full time, so it appears to be some part degrading over time versus an outright failure. Very difficult to troubleshoot and quite frustrating.
kiev = kenny's innovative electric vehicle

Gencis
Posts: 69
Joined: Fri May 04, 2018 2:45 am

Re: Not able to drive. P1A15 error.

Sun May 09, 2021 8:46 pm

To Kiev:
I am preparing the checklist for the electronic workshop. I marked question numbers on the photos. Could you check if I understood correctly?
1. Check the resistance of all the little blue resistors
2. Check resistance from the input posts (VH and VL) to the via near pins 2 and 3 of the operational amplifier on the ISA 215-hybrid board. VH to pin 2 ~100k and VL to pin 3 ~50k.
3. Check 3 ceramic capacitors
Image

Also in any case it would be good to change 3 ceramic capacitors of the hybrid board and operational amplifier B21 with new?

kiev
Posts: 1605
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
Contact: Website

Re: Not able to drive. P1A15 error.

Mon May 10, 2021 7:13 am

Here is the schematic with the board reference designators for the components in question:
Image

The blue resistors and 3 ceramic capacitors (each should be about .39uF, not the 5pF default shown on schematic) are part of the voltage divider network on the input side to the hybrid board that drops the pack voltage down to a lower level compatible with the op amp range. Those marked as 1 in your photo are not involved as far as i know.

There is also a bleed-down network in the path shown with FET2. All those parts need to be checked too if possible just to rule out possible fault paths.

There are parts on the bottom side of the ISA hybrid board that could be checked if that board was desoldered from the main board. i don't have a schematic for the hybrid board but it would be worth checking everything that could be measured on it. The next level of diagnostics would be to power up and test the ISA board on the workbench.

Also on the op amp i measured 100k between pin 6 and pin 2, and 258k between 6 and 3.

If the passive voltage divider network checks out okay, then my guess is the issue is likely on the hybrid board.
kiev = kenny's innovative electric vehicle

Return to “General Technical Discussions”