For automotive enthusiasts and DIY mechanics, a Bluetooth OBD2 car diagnostic scanner tool is an invaluable asset. These handy devices, often utilizing the CAN bus protocol, allow you to tap into your vehicle’s computer to read error codes, monitor performance, and gain insights into your car’s health right from your smartphone. However, many OBD2 scanners draw continuous power, even when your car is off, potentially leading to battery drain over time. This guide will walk you through a simple modification to convert your Bluetooth OBD2 scanner to switched power, ensuring it only operates when your vehicle is running or in ACC mode.
Why Modify Your OBD2 Scanner for Switched Power?
The primary reason to modify your Bluetooth OBD2 scanner for switched power is to prevent battery drain. Standard OBD2 ports provide constant 12V power. While the draw from a single scanner might seem minimal, over days or weeks of inactivity, it can be enough to deplete your car’s battery, especially in vehicles with older or weaker batteries. By switching the power source to an Accessory (ACC) circuit, your scanner will only be active when the ignition is on, eliminating any risk of parasitic battery drain. This modification is particularly beneficial if you leave your scanner plugged in continuously.
Step-by-Step Guide to Modify Your Bluetooth OBD2 Scanner
This guide is based on a modification performed on a BAFX Products PIC18F2480 Bluetooth OBD2 adapter, a popular and well-regarded tool. While the specifics might vary slightly depending on your scanner model, the general principles should be applicable to many similar devices. Always exercise caution when modifying electronic devices and ensure you are comfortable with basic electronics before proceeding.
Tools You’ll Need:
- Small Phillips head screwdriver
- Small flat head screwdriver or similar tool (for gently moving wires)
Modification Steps:
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Open the OBD2 Scanner Housing: Locate and remove the screws holding the scanner’s case together. In the case of the BAFX adapter, these screws are hidden under the blue label. Carefully peel off the label to access the four screws.
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Separate the Case and Disconnect the Connector: Gently separate the two halves of the scanner’s case. You will see a small white connector connecting the OBDII port to the internal circuit board. Carefully unplug this connector.
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Remove the OBDII Connector: With the connector unplugged, you can now lift the OBDII connector assembly completely out of the scanner’s housing. This will give you easier access to the wiring.
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Relocate the Power Wire: Identify pin 16 and pin 8 on the OBDII connector. Pin 16 is typically the constant 12V power supply, and pin 8 is often the switched ACC 12V. In the BAFX adapter (and many others), pin 16 is on the top left, and pin 8 is on the bottom left when viewed from the front. Carefully move the wire currently connected to pin 16 and insert it into the pin 8 slot. You may need a small flat head screwdriver to gently release the wire and guide it into the new position.
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Reassemble the Scanner: Place the OBDII connector assembly back into the housing, and reconnect the white connector to the circuit board. Carefully reassemble the two halves of the case and secure them with the four screws. Be mindful of the internal LEDs while reassembling to avoid bending them.
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Test Your Modified Scanner: Reconnect your modified Bluetooth OBD2 car diagnostic scanner tool to your vehicle’s OBDII port and turn your ignition to ACC or ON. Verify that the scanner now powers on and connects to your smartphone app. Also, ensure it powers off when the ignition is turned off.
Conclusion
By performing this simple modification, you’ve successfully converted your Bluetooth OBD2 car diagnostic scanner tool to switched power. This ensures that your scanner only draws power when your vehicle is running, eliminating the risk of battery drain and providing peace of mind. Enjoy the convenience of continuous monitoring without worrying about unnecessary battery depletion. This modification enhances the usability and longevity of your car diagnostic tool, making it an even more valuable part of your automotive toolkit.
