Can warning lights be cleared before a vehicle is sold?
Codes and warning lights can sometimes be cleared, but supported systems may later record the condition again. Physical checks and readiness or history information can provide additional context.
Does no fault code mean the vehicle has no problems?
No. Many mechanical, wear, body and structural problems do not create a diagnostic code.
Why are some modules shown as unavailable?
The vehicle may not contain that module, the model may use a different communication method, or the available diagnostic access may not support it.
Should codes be cleared during a pre-purchase inspection?
The inspection should preserve and document relevant evidence. Clearing codes can remove useful history and is not part of the reporting purpose.