1. Check the transmission fluid level. If the transmission fluid level is low, it can cause the overdrive light to flash and the car to not start. Check the transmission fluid level using the dipstick located in the engine bay. The transmission fluid should be between the "Full" and "Add" marks on the dipstick. If necessary, add the recommended type of transmission fluid to the transmission.
2. Inspect the transmission fluid condition. If the transmission fluid is dark or dirty, it may need to be changed. Consult your Honda Accord owner's manual for the recommended transmission fluid change interval.
3. Check the overdrive solenoid. The overdrive solenoid is an electrical component that controls the engagement and disengagement of the overdrive gear. If the overdrive solenoid is faulty, it can cause the overdrive light to flash and the car to not start. You can test the overdrive solenoid by disconnecting the electrical connector from the solenoid and then checking for continuity between the terminals. If there is no continuity, the overdrive solenoid is faulty and will need to be replaced.
4. Have the car scanned for diagnostic trouble codes. A diagnostic trouble code (DTC) is a code that is stored in the car's computer when a malfunction is detected. DTCs can be retrieved using a scan tool. Having the car scanned for DTCs can help you to identify the source of the problem and determine the necessary repairs.
If you have tried the above steps and your Honda Accord still does not start, you will need to take it to a qualified mechanic for further diagnosis and repair.
