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Looking for some troubleshooting assistance. Last week I replaced the battery on my 2020 S with an Interstate 95R/H9 (Canadian Car, came with 105AH Varta). Following the replacement the PCM screen is black and will not power up. Fuse to PCM looks to be fine. I am getting PCM communication fault codes with my Autel scan tool. I had a small 2 amp Noco tender hooked to the battery terminal posts under the hood during the battery replacement. Any ideas on what the issue could be or what went wrong during replacement.
 
Looking for some troubleshooting assistance. Last week I replaced the battery on my 2020 S with an Interstate 95R/H9 (Canadian Car, came with 105AH Varta). Following the replacement the PCM screen is black and will not power up. Fuse to PCM looks to be fine. I am getting PCM communication fault codes with my Autel scan tool. I had a small 2 amp Noco tender hooked to the battery terminal posts under the hood during the battery replacement. Any ideas on what the issue could be or what went wrong during replacement.
I can not speak to the specific fault causing your issue, however, the car needs power provided during a battery swap. This power must be a steady source of voltage from a POWER SUPPLY. A tender is NOT a power supply. A tender analyzes the voltage from a battery and uses that info to deliver the correct voltage and amperage based on its charging / maintenance algorithm. e.g. My CTEK tender will throw an error and stop working if not connected to a battery. Also, a 2A POWER SUPPLY is likely too small to be adequate. My 7A CTEK has a power supply mode and that will work as long as major power draws are turned off. Not all chargers / maintainers have a power supply mode. Old fashioned chargers are power supplies.
 
what mataa said....your 2 amp Noco did not supply continuous power to your vehicle. For that you need dedicated charger with a continuous feed power supply. Unfortunately, I cannot help you with the blank screen. I have not experienced that before. I know this seems minor but might be worth trying. Search on the forum how to do a PCM reboot, I think it's hold down the Volume button for 20 seconds. Maybe somehow with the power interruption the screen got turned off and you just have to turn it back on again? Good luck.
 
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