OBD disconnect with car battery charger on

Hi All,

I have a question. I did a few APIM firmware updates on my vehicle, Ford Tourneo Custom 2.0 2018. For the firmware updates it is strongly recommended to use a car battery charger during the updates to make sure the APIM does not brick for an interruption due to low car battery. I have an Obdlink EX and i bought the car charger in amazon, this is the model https://www.amazon.it/gp/product/B084ZJY8ZQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Long story short, when I have the car battery charger connected to the car, the OBD disconnects and connects continously, so I don’t have a stable OBD connection with the vehicle and I can’t do anything with the charger on.

Does anyone know what is the reason behind this disconnection? Just add that it happened the same thing with the Vlinker FS.

Thanks for your replies.

I am going to ask a question: The vehicle engine is not running, right? You would be surprised how often people say yes. Just checking…

But, this usually indicates an issue with the charger connection or battery. Make sure that the negative connection is to the engine or frame. Do not connect the negative lead directly to the battery. This is due to the BMS system, and in the old days sparks and hydrogen gas.

It sounds like a current issue, which is dropping the voltage on the CANBUS and vehicle. You might want to have the battery checked or replaced if it is the original.

Thanks for your reply Chief! I confirm the vehicle is not running and I confirm I connect the negative on the frame. The actual battery is under the driver sit since it is a van, but the connection with the charger is made inside the hood where I have the extended positive pole. My battery was replaced last December, it is almost new and from what I see is working fine apart from this issue.