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Discussion Starter · #21 ·
Got my BMS harness working and hooked up to OBDIIC&C gauge.
Here's how my harness is wired. Important thing to note is how CANH and CANL are daisy-chained and then terminated with a resistor:
87308



87307


Very nice!
 

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Discussion Starter · #23 ·
I'm told there should be a 120 ohm resistor at both ends.
Yes, I didn't show that end because I haven't run the permanent wiring to route it through the OBD port, etc.
I followed Peter's lead and put it directly on the CAN transceiver in the OBDIIC&C gauge.
87314
 

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Discussion Starter · #24 ·
Yep, SRS unit is the one bringing it down. Everything plugged in except SRS connector B, and my OBDIIC&C gauge is working again. Throwing about a million codes right now though
Took it out of the car and powered it up on the bench. Only puts out 1V on the H line. Guess I'll have to buy a new one. If anyone has one available, let me know!
 

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Discussion Starter · #25 ·
Found an SRS on ebay, already received and installed, no more issues there!
 

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Discussion Starter · #27 ·
I did poke around a bit, there were no obviously burnt parts or leaking capacitors or what have you. I checked its internal 5V voltage regulator IC and it seemed fine also. After that I tried to trace the circuit to see where the drop took place but got pretty lost pretty fast.
 

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Discussion Starter · #28 ·
.
 

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Discussion Starter · #29 ·
I bought myself a new insight a few months back, a 2005. I swapped the entire LTO conversion into the new car, including my modded 2001 BCM, MCM, and junction board, but I'm now regularly having the IMA light come on. I checked the MCM DTCs on my OBDIIC&C gauge, and it says:
41 1439 1437 MDM Short Circuit
44 XXXX XXXX Vehicle Speed Signal Circuit Problem
59 1444 0AA6 High Voltage Short Circuit

I still get assist and regen, but it also seems to be constantly trying to regen no matter what the battery level, which is obviously pretty bad for my MPGs

Do I need to use the BCM and MCM that came with this car?

Maybe relevant to the Vehicle Speed Signal - I also moved my Rostra cruise control from the old car to the new one. It taps into that line.

Any other suggestions?
 

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Disconnect the rostra until you sort the IMA faults.

Triple check all your wiring.

Has something got nudged/dislodged in the transfer.

You can use either BCM/MCM pair in the 2005...

When exactly does the IMA light come on?
Can you clear it?
Does it come on with just IGN on for example?
Does it come on when ticking over?
Does it come on only when regening at low rpm but high current?
 

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Discussion Starter · #31 ·
It sometimes comes on soon after I start the engine, after nothing but idling. Most often it comes on after about a minute of driving. I can clear it, yes
 

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So having disconnected the rostra what codes do you have now?

Have you checked the wiring diagrams between the earlier car and the 2005 they might be subtly different
 

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No changes in IMA compartment are necessary between a 2000 and a 2005 model for a basic LTO conversion. But BCM Interceptor with 2000/2001 programming will NOT work in the 2005 as discovered here. So if you've got one of those, best to remove it. I don't think Peter finalized the code for it, as I was the only one attempting to use BCM Interceptor in a 2005 w/ LTO.

That car also gets P1437, but it's only occasional (every couple months). I haven't done the MCM mod on it to stop it from happening, but I should be getting the car back in July (owner going out of town for an extended period) and I hope to fix it at that time. It's got the 40% hack.
 

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Discussion Starter · #34 ·
No
So having disconnected the rostra what codes do you have now?

Have you checked the wiring diagrams between the earlier car and the 2005 they might be subtly different
No change after disconnecting rostra.

No changes in IMA compartment are necessary between a 2000 and a 2005 model for a basic LTO conversion. But BCM Interceptor with 2000/2001 programming will NOT work in the 2005 as discovered here. So if you've got one of those, best to remove it. I don't think Peter finalized the code for it, as I was the only one attempting to use BCM Interceptor in a 2005 w/ LTO.

That car also gets P1437, but it's only occasional (every couple months). I haven't done the MCM mod on it to stop it from happening, but I should be getting the car back in July (owner going out of town for an extended period) and I hope to fix it at that time. It's got the 40% hack.
I do indeed have a mini BCM interceptor installed. Looks like I neglected to document that.
 

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Discussion Starter · #35 ·
So I'm rewiring this from the beginning, basically. Start with my 2005 BCM and MCM, no BCM Interceptor, no current hack, no IMAC&C, no VPIN pre-resistors.

Looking at the BCM fooler - instead of using an optocoupler to switch the battery voltage, could we just take BATT+ from the other side of the main contactor? I confess I don't know much about how the main and bypass contactors are triggered or how they interact.
 

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So I'm rewiring this from the beginning, basically. Start with my 2005 BCM and MCM, no BCM Interceptor, no current hack, no IMAC&C, no VPIN pre-resistors.

Looking at the BCM fooler - instead of using an optocoupler to switch the battery voltage, could we just take BATT+ from the other side of the main contactor? I confess I don't know much about how the main and bypass contactors are triggered or how they interact.
No you can't do that.

The MCM has to see the voltage via the BCM fooler and MCM E plug before it will turn on the contactor.
 

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Discussion Starter · #37 · (Edited)
No you can't do that.

The MCM has to see the voltage via the BCM fooler and MCM E plug before it will turn on the contactor.
Got it. same story with the bypass contactor I assume?

I installed a jumper on the fooler PCB to just bypass the optocoupler for now.
Rather than modding my MCM for 5V output, I should be able to trigger the optocoupler using the same switched 12V (hot side of battery fan motor) that I use for my LTO BMS harness right? increase the current limiting to 1k+?

Current state of mods to my 2005 insight:
72 Cells LTO
BCM Fooler
OBDIIC&C w/LTO CAN Integration
Rostra cruise control

and no codes thrown so far
 

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Discussion Starter · #38 ·

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Well if you are getting a P1444 (59) high voltage short, it means voltage is leaking from the high voltage side to the chassis / 12v side. The resistance between the HV side and LV side is < 300k ohms IIRC.

Measure the voltage between the two main battery terminals on switchboard with the car on and the chassis/12V+
You should not have any steady voltage.. Report back with findings..
 

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Discussion Starter · #40 ·
Yep, (though I suspect it's P0AA6 this time, since I now have my '05 MCM installed)
I was just getting to that part in the DTC troubleshooting, with HV battery OFF, and MCM connector E disconnected (i.e. the BCM fooler) there is infinite resistance shown between MCM lines E4 or E8 (both on the connector and on the MCM itself) and ground.

reconnected the BCM fooler, HV battery ON, and turned key to ON. measuring between top of switchboard battery terminals and chassis, I get voltage fluctuating between 40-75V :unsure:
 
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