Alibro wrote: ↑Tue Sep 12, 2023 3:25 pm
Hi guys
So I've spent a couple of days playing with my Nissan Leaf Gen1 VCU and have not got much further so would appreciate any input.
When I connect the ISA shunt the VCU throws a wobbly and reports all current, temp voltage etc at full scale. But worse it won't reset until I power the VCU off and on and it does this with or without james@N52E01 software tweaks. I don't yet know if my shunt is faulty or I'm doing something wrong.
So I decided to park the shunt for now and try to work without it and see if outputs 1 and two (to drive the contactors) work with the default SW and they do..... sort of.
If I turn on the ignition Input 1 comes on immediately and input two a second or so later which is great. The serial monitor is showing the correct pack voltage too so I although I haven't tested it yet I suspect the car would drive.
However if I turn the ignition off then back on again I get nothing and don't get anything until the battery is disconnected and reconnected.
I tried putting a switch on the positive feed and from the battery to the feed for all so that I could reset everything with the ignition off and it didn't work nor did it work on the negative feed.
At this point I'm more than a little confused as to why disconnecting the battery works but just removing 12V from VCU and inverter doesn't.
I had this setup temporarily working previously but it was cobbled together and I was using timers instead of the VCU to drive the contactors and somehow ended up with welded contactors. I also had the issue then of having to disconnect the battery to get it working so I appear to have an issue somewhere.
Any help appreciated
So with the shunt CAN and low voltage disconnected I moved on and spent several days playing with it until I found a method of connecting and sequencing that works pretty well. It is not perfect and I've since had another issue but it worked well enough to get wheels spinning almost every time I turned on the ignition.
I'll come back to this later and write it out but I want to confirm it is OK before misleading everyone.
Now I have a couple of issues.
1. If I turn off the ignition and back on again it seems the inverter caps are still charged and it won't play nice. I have to wait for a minute or so for the voltage to drop below 150V before turning the ign back on.
2. The motor temperature up to now has always shown as similar to the inverter temp but suddenly is off the scale.
Hoping the two issues above would not cause any issues I bolted the wheels back on and took it out for a test drive. I got about ten feet before it cut out and wouldn't go again so I had the push of shame back into the garage.
I'm working on the issues now but any suggestions welcome.
EDIT: It looks like I have a bad connection somewhere between the motor and inverter as when I messed with the wiring the temp fell to where it should but now the RPM is off the scale. I'll strip the loom back and check it.