It sounds like you’re dealing with a tricky situation. The codes ECU1 ($FD00) and ECU2 ($FD20) typically indicate issues related to the engine control unit (ECU). Here are a few steps you can take to troubleshoot the problem:
Check the Battery and Connections: Ensure the battery is fully charged and the connections are clean and secure. Sometimes, a weak battery or corroded terminals can cause the engine to start but not stay running.
Inspect the Fuel System: A common issue could be related to the fuel system. Check if the fuel pump is working correctly and if there’s adequate fuel pressure. You might need to listen for the fuel pump’s sound when you turn the key to the “on” position.
Examine the ECU and Wiring: Since the codes point to the ECU, inspect the wiring and connectors related to the ECU. Look for any signs of damage or corrosion.
Check for Vacuum Leaks: Sometimes, vacuum leaks can cause the engine to start and then stall. Inspect the vacuum hoses for any cracks or disconnections.
Consult a Professional: If you’re unable to resolve the issue, it might be best to consult a professional mechanic, especially since you’re away from home. They can perform a more thorough diagnostic and pinpoint the exact cause.
Since you’re in DC, you might want to look for a nearby Lexus dealership or a reputable auto repair shop that can assist you.