OBD2 scanners are invaluable tools for diagnosing car problems, but a common question is: Does Obd2 Clear Codes? The answer isn’t a simple yes or no. This article dives into the different types of diagnostic trouble codes (DTCs) and how they can be cleared, focusing on the capabilities of an OBD2 scanner.
Different Types of Diagnostic Trouble Codes (DTCs)
There are three main types of DTCs:
Permanent DTCs: OBD2 Can’t Clear These
Permanent DTCs, as defined by the Bureau of Automotive Repair (BAR), are stubborn. Unlike regular codes, disconnecting the battery or using an OBD2 scanner won’t clear them. A permanent DTC indicates a serious issue that needs to be fixed. The code will only clear itself after the underlying problem is resolved and the vehicle’s onboard diagnostics system (OBD) re-runs the monitor that initially detected the fault without finding the issue again. So, while an OBD2 scanner can read these codes, it can’t erase them.
Pending DTCs: They Might Clear Themselves
Pending DTCs represent intermittent problems or issues that the Powertrain Control Module (PCM) needs to observe in two consecutive warm-up cycles to confirm. If the problem doesn’t reappear within 40 warm-up cycles, the pending code will automatically disappear. If the fault reoccurs, the pending code becomes a full-fledged DTC, triggering the check engine light. An OBD2 scanner can read pending codes, but clearing them might not be necessary as they often resolve themselves.
History DTCs: OBD2 Might Help, But It Depends
History DTCs are records of past problems that have been fixed. Some history codes can be cleared with an OBD2 scanner, while others require specific driving conditions or a double clearing process. Consulting your vehicle’s service manual is crucial for understanding how to clear specific history codes. The manual will outline the necessary conditions for clearing them.
Conclusion: Does OBD2 Clear Codes? It’s Complicated
So, does OBD2 clear codes? It can clear some, but not all. While an OBD2 scanner is essential for reading and sometimes clearing codes, it’s not a magic bullet. Permanent DTCs require fixing the underlying problem, pending codes might clear themselves, and history codes often have specific clearing requirements. Understanding the different types of DTCs and consulting your vehicle’s service manual are crucial for effective diagnostics and repair.
