Navigating the complexities of modern vehicle diagnostics often requires understanding car scanner numbers. For teams working on vehicle maintenance or repair, especially when dealing with 2017 and similar models, interpreting these numbers is crucial. Diagnostic Trouble Codes (DTCs) can sometimes be persistent, and not all scanners are created equal when it comes to clearing them. Let’s delve into why some DTCs refuse to disappear and how to effectively use your car scanner.
One common frustration arises when using a generic OBD2 scanner. While these scanners are excellent for reading “P” or powertrain codes, their capabilities can be limited when it comes to other code groups. These include “C” chassis codes (often related to ABS), “B” body codes, and “U” network codes. For instance, an ABS DTC might be stored, and while a generic scanner might indicate a “P” code related to the ABS, it may lack the ability to communicate directly with the ABS unit to read and clear the specific chassis code. The same principle applies to “P” codes linked to the Transmission Control Unit (TCM); a deeper level of communication is needed to interact with and clear codes from the TCM.
Generic scanners often don’t support all ten modes of operation defined within the OBD-II standard. Furthermore, vehicle manufacturers may implement proprietary modes beyond the standard OBD-II protocols. This means that for a comprehensive diagnostic approach, especially when aiming to clear persistent codes, a more advanced scanner might be necessary. Beyond just the DTC itself, diagnostic systems also capture freeze-frame data, which provides a snapshot of parameters when the fault occurred, and historical data, offering a broader view of past issues.
When considering DTCs that are particularly stubborn, “hard codes” or Mode-10 (x’0A) permanent codes are likely the culprit. OBD-II standards define different modes for accessing diagnostic information. Mode-3 reveals stored diagnostic trouble codes, while Mode-2 provides freeze frame data associated with a fault. Mode-4 is typically used to clear fault codes and turn off the malfunction indicator lamp. Mode-7 shows pending or unconfirmed fault codes. Mode-10, however, is unique; it displays permanent fault codes.
Mode-10 codes mirror those in modes 3 and 7 but cannot be cleared using the standard Mode-4 clear command. These permanent codes are designed to ensure that a fault is truly resolved before being cleared. The only way to clear Mode-10 codes, assuming the underlying issue has been fixed, is through repeated drive cycles where the vehicle’s internal diagnostics confirm the problem is no longer present. This might involve specific driving patterns over several trips.
For teams requiring a more immediate solution, diagnostic systems like the wiTech system used at dealerships offer enhanced capabilities. These advanced systems can often run in-depth diagnostics and clear Mode-10 codes if no faults are actively detected during the diagnostic process. If access to such a system isn’t available, and Mode-10 codes persist even after repairs, the alternative is to complete the necessary drive cycles. This allows the car’s own diagnostic system to verify the fix and automatically clear the permanent fault, ensuring accurate car scanner numbers for future diagnostics.
