For automotive enthusiasts and DIY mechanics, the Elm327 Obd2 Obdii V1 4 Bluetooth Diagnostic Interface is an invaluable tool. These interfaces, compatible with a wide range of vehicles, allow you to access your car’s onboard diagnostics system using your smartphone or tablet. Many users appreciate the convenience and affordability of devices like the BAFX Products PIC18F2480 Bluetooth OBD2 adapter, known for its solid connection and compatibility.
However, a common issue with many OBD2 adapters is that they draw constant power from your car’s battery, even when the ignition is off. This can lead to battery drain over time, especially if your vehicle is not driven frequently. The good news is that it’s relatively simple to modify your ELM327 OBD2 OBDII V1 4 Bluetooth Diagnostic Interface to draw power only when the ignition is switched on, preventing unnecessary battery drain. This modification involves switching the power source from a constant 12V pin to a switched Accessory (ACC) 12V pin within the OBD2 adapter itself.
This guide will walk you through a straightforward modification to convert your ELM327 OBD2 OBDII V1 4 Bluetooth Diagnostic Interface to switched 12V power. This ensures that your diagnostic tool only draws power when the car is running or in accessory mode, eliminating the risk of battery drain. This modification is particularly useful if you leave your ELM327 OBD2 OBDII V1 4 Bluetooth Diagnostic Interface plugged into your vehicle for extended periods.
Step-by-Step Guide to Modify Your ELM327 OBD2 Adapter for Switched 12V Power
This modification is designed to be simple and reversible, requiring only basic tools and about 15 minutes of your time. Before you begin, ensure your vehicle is turned off and the keys are removed from the ignition.
Tools You Will Need:
- Small Phillips head screwdriver
- (Optional) Small pick or similar tool to assist with wire manipulation
Procedure:
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Open the Adapter Casing: Locate the four screws that secure the two halves of your ELM327 OBD2 OBDII V1 4 Bluetooth Diagnostic Interface casing. On many models, these screws are hidden beneath a label. Carefully peel back the label to expose the screws. Use your Phillips head screwdriver to remove all four screws.
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Separate the Casing and Disconnect the Connector: Gently separate the two halves of the adapter casing. Inside, you will see a small white connector connecting the OBDII port to the PC board. Carefully unplug this white connector from the PC board.
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Remove the OBDII Connector: Once the connector is unplugged, you can lift the OBDII connector assembly entirely out of the adapter’s shell. This provides easy access to the pins.
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Relocate the Power Wire: Identify pin 16 and pin 8 on the OBDII connector. Pin 16 (typically a thicker wire) is the constant 12V power supply. Pin 8 is the switched ACC 12V power supply. Carefully move the wire currently connected to pin 16 to pin 8. On many adapters, pin 16 is located at the top left, and pin 8 is at the bottom left, making this a straightforward move. You may need a small pick or tool to gently release the wire from the connector and re-insert it into the pin 8 position.
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Reassemble the Connector and Casing: Place the OBDII connector assembly back into the adapter shell. Re-plug the white connector back into the PC board. Carefully reassemble the two halves of the casing, ensuring you don’t bend any internal components, such as the LEDs if present.
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Secure the Casing: Replace and tighten the four screws to secure the adapter casing.
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Reapply the Label (Optional): If you wish, you can reapply the label to the adapter. Alternatively, you can leave it off.
Testing Your Modified ELM327 OBD2 Interface
After reassembly, your ELM327 OBD2 OBDII V1 4 Bluetooth Diagnostic Interface should now only power on when your car’s ignition is turned to the “ON” or “ACC” position. Test the adapter by plugging it back into your vehicle’s OBDII port and turning the ignition on. Use your preferred OBD2 diagnostic app to confirm that the adapter powers up and connects correctly. You should find that it functions exactly as before, but now with the added benefit of switched power, preventing battery drain and enhancing the longevity of your car’s battery.
This simple modification enhances the practicality of your ELM327 OBD2 OBDII V1 4 Bluetooth Diagnostic Interface, making it an even more user-friendly tool for automotive diagnostics.
