Analysing the BCM/MCM Signals

[retepsnikrep]

Mike

Thanks for that advice. Luckily this unit/pcb doesnt seem to be affected like the BMS was, probably something to do with it not having EMI pick up leads buried in/connected to the battery pack etc.

[retepsnikrep]

Here is some BCM BATTSCI bus data I captured of the temp sensors being manipulated.

1st PTC sensor faked and resistance increased with a pot until IMA light P1449 occurs.

2nd The four temp sensors heated with hot air gun until IMA light & P1568 occurs.

I noticed that heating (Virtually melting) individual sensors had no effect.

Even two or three had no effect. All four had to be heated together to generate the error.

I haven't looked at this data yet myself.

www.solarvan.co.uk/bcm/TempData.zip

I need to look for the fan point as well just for info.

[E27006]

I have taken a look at the file HightTemp3P1568.

Is the following sequence the point at which the code P1568 was triggered? When time =15.4287000 seconds?

That is the first point when you have a major change in the checksum, 34 becomes 74.
the fiufth byte has changed from 00 to 40hex

15.3677750,0xAA,,
15.3689400,0x10,,
15.3701000,0x00,,
15.3712650,0x00,,
15.3724250,0x00,,
15.3735900,0x00,,
15.3747500,0x20,,
15.3759150,0x61,,
15.3770750,0x10,,
15.3782400,0x01,,
15.3794000,0x00,,
15.3805650,0x34,,

15.3977900,0x87,,
15.3989500,0x40,,
15.4001150,0x52,,
15.4012750,0x00,,
15.4024350,0x00,,
15.4036000,0x10,,
15.4047600,0x01,,
15.4059250,0x32,,
15.4070850,0x3E,,
15.4082500,0x3C,,
15.4094100,0x05,,
15.4105750,0x25,,

15.4278000,0xAA,,
15.4289600,0x10,,
15.4301250,0x00,,
15.4312850,0x00,,
15.4324500,0x40,,
15.4336100,0x00,,
15.4347700,0x20,,
15.4359350,0x61,,
15.4370950,0x10,,
15.4382600,0x01,,
15.4394200,0x00,,
15.4405850,0x74,,

15.4578100,0x87,,
15.4589700,0x40,,
15.4601350,0x52,,
15.4612950,0x00,,
15.4624600,0x00,,
15.4636200,0x10,,
15.4647850,0x01,,
15.4659450,0x32,,
15.4671100,0x3E,,
15.4682700,0x3C,,
15.4694300,0x05,,
15.4705950,0x25,,

[retepsnikrep]

That's possible Malcolm, I need to get my wife the excel expert to help me put these files into a better format.

Also in the PTC test, byte six of the $AA packet changes from $00 to $01.

I'll try sending those codes today and see what the car does.

In the High Temp 1 P1568 test where I heated all the temp sensors together

The fifth byte of $AA Changes to $40, then to $48, then $4F

Then byte four changes from $00 to $08

This also occurs in the High Temp 3 test.

So looks like Fourth byte of AA changing to $08 is the P1568 trigger code
and the sixth byte of AA changing to $01 is the P1449 trigger code

EDIT

Confirmed just now with the interceptor sending $08 causes P1568 and $01 causes P1449

[IamIan]

Originally Posted by retepsnikrep

EDIT

Confirmed just now with the interceptor sending $08 causes P1568 and $01 causes P1449

bit by bit the secrets are revealed.

[evplasmaman]

Hi everyone,
I just spent the last few hours pouring through all the past 11 pages of posts, man you guys did a lot of work! I have a 2000 Honda insight with it's 3rd dead battery and as it's a salvage title Honda want's nothing to do with it. All the previous packs were from wrecks and they lasted for different lengths of time. I'm in the process of trying to fix up a pack so I can restore IMA but these cells look pretty toasty. I love this car but a 990cc engine with 3 cylinders of fury is just not going to cut it.

My plan is to follow in Peter's foot steps and add in a larger lithium battery pack and then get a MIMA system as well.

I put together a quick diagram of how i think the IMA system works, Could some one please verify that for me? It may also be a useful diagram for anyone else wanting to do this.


Also I have a bit of experience with building PCBs. I would like to put together a board with all the necessary transceivers and a single PIC with two built in UARTS. Something like a PIC32 although that's complete overkill. Peter have you made any progress on yours?

Hope everyone is having a great holiday,
Jos++

www.evplasmaman.com

[retepsnikrep]

Diagram looks good. The ECM also communicates with the MCM with IMA (MIMA) signals but not using any serial data ASFAIK.

Can't remember if you have the inverted/non inverted the right way round. But if it doesnt work one way just swap them round

I have the BCM Interceptor board which can sit on the BATTSCI or METSCII bus and be programmed to interact to fake BCM data or gauge data as we wish. My long term aim is to get rid of the stock BCM but that's not so easy as it gathers a lot of info which any replacement would also have to do.

You have a nice website with interesting projects. Just a word of advice on the BMS. The Insight IPU compartment is one of the noisiest pleces I have ever seen from an EMIRFI point of view. It took me 6 months to get my BMS to work in it!

Please keep us updated with your progress.