One of our customers encountered a short circuit issue while reading the data of this MQB49 5C smart key using Keydiy KD-X4. As a result, the remote control function stopped working, and only emergency starts.
Possible causes of the short circuit:
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Soldering wires caused bridging, leading to a short circuit under the chip.
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The soldering iron temperature was too high, and repeated re-soldering caused a short circuit under the chip.
Solution:
Clean around the chip thoroughly, then apply reflow soldering (re-solder all pins/pads).
Tips to read this type of 5C smart key via soldering:
Remove the glue from this point.
Set your hot air gun to 180°C.
Keep it a little away from the pins and heat in a circular motion (move in circles).
Once the temperature comes up, use a blade to remove the glue (de-glue / remove adhesive).
Then clean up the surrounding area.
If you want better contact, use a soldering iron to add a little solder to this pin.
The best way is to use the solder free adapters. The connection points on the adapter are fixed, which prevents VCC or wake errors.
