Service engine light is on and Overdrive light on gear shift blinking?

Hello,

The service engine light gets triggered when the onboard diagnostics detect any fault within the powertrain management system. This can be any number of sensor(s) or part(s).
It can also be due to an emission issue.

Overdrive light flashing can mean an issue with the transmission, could be a speed sensor or a solenoid.

Are you experiencing any drivability issues?

The best course of action would be to scan the vehicle and retrieve the error code(s). This can help with the diagnostics by narrowing down the possible causes.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let me know what code(s) that you retrieve or if you have any questions.

Thank you.