bq27441 CONFIG UPDATE mode not working sometimes

I don't know. Where can I check this?

I check the CONTROL_STATUS register and there is no difference when error occurs. And I noticed that the SS bit in the CONTROL_STATUS is never set even if a device is in a sealed state. The high byte of the CONTROL_STATUS is always 0x0B.

How are you testing this? Is this with bqStudio and an EV2x00?

No, I have custom board.

If the SS bit isn't set when the device is in sealed state then there's likely something wrong with the communication between your host uC and the gauge. Did you check if the communication protocol is correct and works without errors?

Yes there was a little mistake at reading CONTROL_STATUS. I forget to put one command. Now SS bit is set when device is in sealed mode. So I noticed when flag CFGUPMODE doesn't get set, the SS bit is still set. And usually the low byte of CONTROL_STATUS is 0x8E when it works OK and 0x0E when is not working. But not always.

I removed the final command Control(SEALED) and now the gauge unseal normally. It still get sealed with command Control(SOFT_RESET). So the gauge has problem if it is already sealed and gets the Control(SEALED) command. Why? In the technical reference manual it is suggested that we finish update with the SEALED command.