For automotive enthusiasts and DIY mechanics, having an OBDII scanner is an invaluable tool. Devices like the Elm327 Usb Interface Obdii Obd2 Scanner Canbus Tool provide access to your vehicle’s diagnostics, allowing you to read trouble codes, monitor performance, and much more. However, many OBDII adapters draw power continuously from your car’s battery, even when the ignition is off, potentially leading to battery drain over time. This article will guide you through a simple modification to convert your OBDII scanner to switched power, ensuring it only operates when your vehicle is running or in accessory mode.
One popular and well-regarded OBDII adapter, the BAFX Products PIC18F2480 Bluetooth OBD2 adapter, serves as an excellent example for this modification. While this guide specifically references this model due to its ease of modification and clear internal layout, the principles can be applied to many similar ELM327 USB interface OBDII OBD2 scanner CANBUS tools. The modification involves rerouting the power supply from the constant 12V pin to a switched 12V source within the adapter itself.
Why modify your OBDII scanner for switched power? The primary benefit is preventing unnecessary battery drain. Leaving a constantly powered OBDII scanner plugged into your vehicle can slowly deplete the battery, especially if the vehicle is not driven frequently. By switching the power source, the adapter only draws power when the ignition is on, eliminating this risk and ensuring your battery remains charged for when you need it most. This is particularly useful if you regularly leave your OBDII scanner plugged in for monitoring or data logging purposes.
Modifying your ELM327 USB interface OBDII OBD2 scanner for switched power is a straightforward process that can be completed in about 15 minutes with basic tools. Here’s a step-by-step guide based on the BAFX Products PIC18F2480, which can be adapted for similar devices:
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Accessing the Internals: Begin by locating and removing the four screws that secure the adapter’s housing. On the BAFX adapter, these screws are hidden beneath the blue product label. Carefully peel back the adhesive label to expose the screws and remove them.
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Separating the Housing and Disconnecting the PCB: Once the screws are removed, gently separate the two halves of the adapter’s housing. Inside, you’ll see the printed circuit board (PCB). Carefully unplug the white connector that connects the OBDII port to the PCB. This will allow you to remove the OBDII connector from the housing for easier access.
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Pin Relocation for Switched Power: The crucial step involves moving the wire on pin 16, which is the constant 12V supply, to pin 8, which is typically designated for switched ACC (Accessory) 12V power. Looking at the OBDII connector, pin 16 is usually located at the top left, and pin 8 at the bottom left. Carefully depin the wire from pin 16 and re-insert it into pin 8. This simple wire relocation is what switches the power source.
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Reassembly: After relocating the pin, carefully place the OBDII connector back into its housing within the adapter. Reconnect the white connector to the PCB, ensuring it is securely plugged in. Now, reassemble the two halves of the housing and secure them with the four screws you removed earlier. Be mindful of the internal components, especially any LEDs, to avoid bending or damaging them during reassembly.
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Final Touches: If desired, you can reapply the product label. Alternatively, you can leave it off if you prefer a cleaner look or anticipate future modifications.
After completing this modification, your ELM327 USB interface OBDII OBD2 scanner CANBUS tool will now only receive power when your car is turned on or in accessory mode. This ensures it functions exactly as before when you need it, but eliminates the risk of battery drain when your vehicle is parked. This simple DIY project enhances the practicality and longevity of your OBDII scanner, making it an even more valuable tool for automotive diagnostics and maintenance.
