A few general questions:
- Does anyone know if Lexus cars (2010 if it matters) will throw codes to a computer if there are no lights or warning indicators on the dash? Or do they only throw codes when those lights turn on as an indication something is wrong?
- I just had some codes pop up a couple of weeks ago, my indy cleared them through an ECU update but I'm taking the truck into Lexus for something separate and trying to determine if I should get their advice on what to do based on the combo of codes that showed up initially.

 

When a fault is detected, the system stores a diagnostic trouble code (DTC) in the vehicle's computer memory. These codes can be retrieved using a diagnostic scanner or code reader, even if there are no visible warning indicators on the dashboard.

In your case, if your independent mechanic cleared the codes through an ECU update, it's possible that the underlying issue still exists, but the symptoms or conditions that triggered the codes have temporarily subsided. If the issues were not resolved, it's likely that the codes could reappear over time.