Troubleshooting Car Issues: Understanding DTC Codes and Freeze Frame Data

What happens to a DTC code after 40 warm-up cycles without a fault?

A) It is cleared from active memory

B) It is stored as history data

C) It is erased permanently

D) It triggers a warning light

Answer:

The correct answer is A) It is cleared from active memory.

When a car's onboard diagnostic system detects a fault, a Diagnostic Trouble Code (DTC) is generated and stored in the system's active memory. After 40 warm-up cycles without any fault, the DTC code is automatically cleared from the active memory.

However, it is important to note that even though the DTC code is erased from active memory, it is still stored as history data along with freeze frame data. This history code and freeze frame data will remain in the system until it is manually cleared by a technician.

By understanding how DTC codes and freeze frame data work, car owners and technicians can effectively diagnose and troubleshoot car issues to ensure smooth and efficient performance.