Inside the G1 MDM & more power!

[retepsnikrep]

For the 4 MCM Current sensors

+5v > 1k Resistor > Signal > 1k Resistor > Ground

[steveo]

ImageUploadedByAG Free1352517161.136887.jpgImageUploadedByAG Free1352517200.902334.jpg

Here is the mod i did, i have used 1k 1% resistors 1/4 watt and a 68ohms 2w 5% resistor in the mcm

I have tried to install the modded mcm & bcm and i got the following errors on startup

Does the 68 ohms have to be 1% also? I couldnt source one at my local electrons store.. Gona have to order if its the cause if the errors

P1585 & p1581


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[retepsnikrep]

I can't see anything useful in those pics far too small.

Yes the 68R needs to be a 1% type. The whole accuracy of the battery sensor depends on it.

[steveo]

I believe i've fixed the temp error i was getting.. I used 10k resistors wired in exactly how the original oem sensors where.. and am now using a 82ohm resistor to trick the ptc strips... all resistors are 1% 1/4 rated... since i know the insight is really picky... running for 2 days and no p1648 error or p1644 errors so far

thanks
-steveo

[Mike Dabrowski 2000]

Steveo
The PTC total resistance should be closer to 20 ohms. that is what the strips read in ohms in normal ambient temperatures. The pack has to get pretty hot befire the PTC will be at 83 ohms.
83 is the value that my charger reads when the strip is at 20 ohms, but that is not ohms, just a value.
Worth a try.

[steveo]

Originally Posted by Mike Dabrowski 2000

Steveo
The PTC total resistance should be closer to 20 ohms. that is what the strips read in ohms in normal ambient temperatures. The pack has to get pretty hot befire the PTC will be at 83 ohms.
83 is the value that my charger reads when the strip is at 20 ohms, but that is not ohms, just a value.
Worth a try.

Hey Mike,

I originaly was using a 24ohms resistor where the original ptc sensors wired up .. so your saying 20ohms is ok to use instead of my 82ohms resistor? or even my 24ohms original resistor would of been ok..

I remember checking this with my fluke meter on the oem pack..

thanks

[Mike Dabrowski 2000]

The 24 ohms is fine, there seems to be a deviation of several ohms on the 6 or so that I have measured.
Just would hate to have you falling into a boundary condition.
Good luck

[steveo]

Hey everyone

I have changed all the resistors to 1% and im still getting the p1585 error

Now i bought these resistors of ebay, i dont know if maybe they are not really 1% who knows.. There probably our of china

Anyways, do you still think its the resistors? Im 99.9% sure its modded correctly.

Thanks
Steveo


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[retepsnikrep]

Which mod are we talking about?

BCM Fooler?

Current Hack?

Assuming you mean the current hack

It's possible due to some variation in the MCM's that the 1k etc is too low for your car and you can't shoot for such a large current increase.

I posted a spreadsheet and various other bits on how to calculate resistor values some time back. I suggest have a look through all that. I don't have the links you'll have to dig it out.

Peter

[steveo]

Originally Posted by retepsnikrep

Here is a tiny excel spreadsheet for working out the current hack resistor values.

Type in a % increase number you want from say 12-20% and hit enter to get the values for the two resistors. Thanks to my long suffering wife for her expert help with Excel and the Maths

I have tested 12%, 15% & 17% increase so far with no problems, I might test 20% today if i get a chance. I found 25% did not work in earlier tesing, but might give it another go later with values from my spreadsheet.

% increases of less than 12% are not possible with the 3.3k potential divider i am using, but if someone wanted to try 4.7k resistors for the Pd then it may be possible to get lower % increases. Spreadsheet formula would have to be adjusted.

I recommend accurate multi turn (20) pots for the resistors. 1k for the BCM part and 220 or 500R for the MCM part.

Do not increase current by more than 12% without upgrading main IMA 100A fuse!

I recommend all connections/resistors are made/placed inside BCM/MCM modules to screen mods from RF noise.

PS

If you want to observe your new current you will need a special compensated version of the BCM gauge software, currently I have 12, 17 & 20% versions available by special request.

Hey Peter

thanks for pointing me in the right direction..

just to clarify on your diagram you used a value of 3.3k resistors (1% i assume) for r4 & r5... however you mentioned that it was ok to use a 1 k resistor now instead ... a couple posts back here... is that correct?

Also.. i noticed that my connection from the mcm current sensor does not have the "r6" resistor value you indicated in the diagram.. so this is most likley why i'm getting the p 1585 error

i will retest this mod when i have a chance..

-steveo