Flat battery, car will not start after charging, code P0685-01

2008 VAUXHALL CORSA
145,000 MILES • 1.3L • TURBO • 2WD • MANUAL
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ZEZEGO
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Hello, so yesterday I tried to turn my car on but it didn't work. I though it is a problem with battery as day before it was a bit hard to turn it on, so I charged battery overnight. Now when i try to start the car i can hear only one "click" noise and nothing more. All ights, radio etc., works, it's just engine that doesn't want to start.

Plugged in my laptop with OP-COM software to read codes and after clearing all codes i getting only one which is:

"P0685-01 main relay circuit high voltage"

Any ideas what it could be and how to fix it??
Jan 4, 2021 at 1:38 AM
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KASEKENNY
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This could be an issue with the relay or engine control module but with the battery in its current state I suspect the battery is the issue. Let's load test the battery using the guide below and replace the battery if needed.

https://www.2carpros.com/articles/car-battery-load-test

Here is a guide that will help with the replacement:

https://www.2carpros.com/articles/how-to-replace-a-car-battery

Once you replace the battery I would suggest retesting all of this. I suspect the code will go away and the engine will start normally.

We don't have a manual on this vehicle as it is not offered here in the USA but I am sure we can figure this out with this info. Thanks
Jan 5, 2021 at 3:51 PM