Diagnostics
DTC scanning
Reading fault codes by status, freeze frames, clearing and diffs.
A control unit may store a fault code when it detects a problem. Fault Codes shows the codes returned by the units that answered the scan. A code is a clue about the system that noticed a problem; it does not, by itself, identify the part that needs replacing.
Read the list#
The screen starts with faults that need attention, mainly active and pending codes. You can include stored codes and filter the list by status or system. An active code means its fault condition was reported at the scan; pending means the unit has seen a condition that has not yet been confirmed. A stored code records a confirmed event and may remain after the condition stops. The exact meaning depends on the status reported by that unit.
Select a code to see the explanation Hanterill has for it and the supporting data the car returns. Some units provide a snapshot of conditions when the code was set, such as mileage or voltage; others provide little or none. A snapshot belongs to that code and unit. Do not assume that every code includes speed, temperature or the same counters. Code Lookup can explain a known code without connecting to a car.
Compare scans#
The comparison tools can show codes that appeared, disappeared or changed status between two scans. Make sure both scans belong to the same car. A code missing from an incomplete scan is not proof that the underlying problem is gone.
Clear codes only when appropriate#
Clearing changes the car's stored fault memory and can erase information needed for diagnosis. In a build that permits write operations, the app asks for confirmation. It normally targets units that reported faults; you can choose a wider scope. Backing up available fault snapshots and verifying with another scan are enabled by default, but you can change those options. An optional unit restart is a separate choice and may be refused by the car.
In a read-only build, Clear fault codes does not transmit a clear command. The app offers a comparison workflow instead. After any attempted clear, check the result for each unit and scan again. A code that returns points to a condition that still needs attention.