Delay startup of 1 minute

Topics concerning the Tesla front and rear drive unit drop-in board
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hanstoorman
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Joined: Wed Mar 12, 2025 11:11 am

Delay startup of 1 minute

Post by hanstoorman »

After startup, the car will not move for about 1–2 minutes, even though:
• opmode = run
• status = none
• no error flags
• potnom correctly goes from 0–100%

If I keep the throttle pressed after 1 minute suddenly the car starts moving. Once the car strats driving everything works perfect.
If I switch of the contact and restart immediately after driving, the problem returns.

Setup:
• Tesla Small Drive Unit 2016
• OpenInverter Tesla drop-in board
• Firmware: 5.40.R (also tested 5.35.R, same behavior)

This is my third car I build with the open inverter board, never experienced this behavior. Please help!
P.S.Mangelsdorf
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Re: Delay startup of 1 minute

Post by P.S.Mangelsdorf »

That's really odd behavior.

Based on the run status, I think that eliminates a precharge error, though it certainly seems like that could be it.

Do you have a brake signal and are you stepping on the brake when you put it in gear (I assume so given your experience).

Are you using the same parameters as on the other cars? If not, can you share parameters?

Can you get a data log of at least opmode, status, potnom, and udc?
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hanstoorman
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Re: Delay startup of 1 minute

Post by hanstoorman »

I found the problem, the HV connectors where a bit dirty. After cleaning the problem was gone!

Thanx for replying Mangelsdorf!
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tom91
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Re: Delay startup of 1 minute

Post by tom91 »

That makes no sense, this is not how electricity works. I would fully review all your wiring and HV circuits.
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P.S.Mangelsdorf
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Re: Delay startup of 1 minute

Post by P.S.Mangelsdorf »

I've got to agree with Tom here, that doesn't quite add up.
If at first you don't succeed, buy a bigger hammer.

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hanstoorman
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Re: Delay startup of 1 minute

Post by hanstoorman »

While testing the SDU I accidently switched off the 12V while the motor was turning, blew up my inverter :( :(

I had a spare SDU in stock and changed the inverter, doing that I discovered that the 2pin IL connecter on the openinverter board was loose.
This could be the cause of the startup delay....

After changing the inverter all works fine again.
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