Understanding the question:
The question asks about how long the mechanic has been working on the vehicle since morning. The answer should provide detailed information about the mechanic's work on the vehicle.

Response:
The mechanic has been working on the vehicle since the morning. Here are the details of the work done by the mechanic:

Inspection:
The mechanic started by inspecting the vehicle thoroughly to identify any issues that need to be fixed.

Diagnosis:
After identifying the issues, the mechanic diagnosed the problems to determine the best course of action.

Repairs:
The mechanic then started repairing the vehicle, replacing any faulty parts and fixing any issues. The repairs could include fixing the engine, brakes, transmission, or other parts.

Testing:
After the repairs were completed, the mechanic tested the vehicle to ensure that it was running smoothly and all issues were fixed.

Conclusion:
The mechanic has been working on the vehicle since the morning, inspecting, diagnosing, repairing, and testing it to ensure that it is in good working condition.