For car enthusiasts looking to enhance their vehicle’s performance, chipping the OBD2 ECU (Engine Control Unit) can be an appealing option. This modification, particularly relevant for older Honda models with OBD-II ECUs from 1996 to 2001, involves replacing the stock MCU (Microcontroller Unit) with a performance-oriented chip. This guide provides a step-by-step walkthrough for those interested in undertaking this DIY project.
Step-by-Step Guide to Chip Your OBD2 ECU
Before starting, ensure you have the right tools, including a desoldering tool, soldering iron, PLCC IC socket, and the new performance MCU chip designed for your specific ECU. Work carefully and in a well-lit area to avoid damaging sensitive components.
Step 1: Accessing the ECU and Identifying the MCU
First, locate your vehicle’s ECU. In many Honda models of the specified years, it’s often found under the dashboard or under the passenger seat. Once you’ve accessed the ECU, carefully open its top cover.
With the top cover removed, you’ll see the component side of the ECU. Identify the stock MCU. It’s typically an 84-pin PLCC square chip marked “Oki 66507.” On a top view, it’s usually located at the lower-left corner, away from the ECU plug. This chip is usually the largest on the board, making it relatively easy to spot.
Step 2: Desoldering the Stock MCU
This step requires precision and patience. Using a needle-point desoldering aid, such as CHIPQUIK, apply heat to the base of each pin of the stock MCU. Avoid overheating to prevent damage to the chip if you intend to reuse it.
Employ a solder pump to remove the melted solder from each pin. Pins, especially ground pins or pin 1, may require extra heat and effort due to larger solder pads. Once all pins are desoldered, carefully remove the stock MCU chip.
Step 3: Installing the IC Socket
With the stock MCU removed, you’re ready to install an 84-pin PLCC IC socket. This socket allows for easy chip swapping in the future and protects the new performance chip. Position the socket in the exact location where the stock MCU was removed.
Solder the pins of the IC socket securely to the ECU board. After soldering, use a multimeter to check for any shorts between pins, ensuring a clean installation. Clean the soldered area with a solvent like thinner or methanol to remove any flux residue, which can cause corrosion or electrical issues over time.
Step 4: Inserting the New Performance Chip
Now, take your newly reprogrammed or racing MCU chip. Ensure it’s compatible with your ECU and intended for performance enhancement.
Carefully align the chip with the IC socket and gently insert it. Ensure all pins are correctly seated in the socket.
Step 5: Final Steps and Testing
With the new chip installed, carefully reassemble the ECU by putting the top and bottom covers back on. Reinstall the ECU in your car, reconnect the battery’s positive terminal, and start your vehicle.
If everything is successful, the car should start and run smoothly without any check engine lights. Rev the engine past 4000rpm to verify the chip’s functionality and that it overcomes the stock ECU’s rev limiter.
Conclusion
Successfully chipping your OBD2 ECU can be a rewarding DIY performance upgrade. By following these steps carefully, you can potentially unlock more performance from your older Honda vehicle. However, remember to proceed with caution and ensure you have the correct chip and tools for the job. Enjoy the enhanced driving experience!
