What changed
An AI enthusiast, Muhammad Zulali, successfully got his 1994 Jeep Cherokee to pass California smog tests by using AI tools and hardware modifications. The car initially failed due to excessive NOx emissions at specific test speeds. Zulali connected the Jeep's engine control unit (ECU) to a laptop via an Arduino Nano board, allowing him to read and adjust settings.
What this means in practice
Zulali used Claude AI for diagnostic guidance and Codex for writing code to control the Jeep's emissions. The Arduino Nano handled the interface between the old Chrysler SCI bus and a modern laptop, overcoming the challenge of electrical inversion. The project involved connecting three wires to the 6-pin diagnostic plug in the Cherokee. After collecting data from test drives, Zulali injected custom code into an EEPROM to address the emission issues, bypassing the lack of reflashable firmware in the car's ECU. The solution cost less than $15 in materials, with the Arduino Nano being the primary component.
Limitations and availability
The Jeep's ECU was too old to support firmware reflashing, so Zulali used an EEPROM instead. The project is open-source, with a GitHub repository named xj-scanner available under the GPLv3 license. The solution is specific to the Chrysler SCI bus and may not apply to other vehicle systems. The method relies on the availability of a 6-pin diagnostic plug and the ability to interface with an Arduino Nano. The supplied announcement does not specify whether the approach can be applied to other vehicles or if the ECU interface is standard across all 1994 Jeep Cherokees.
