A scan supports the repair process
A pre-scan records the electronic condition of the vehicle before repair. A post-repair scan checks the vehicle after work is complete. Neither scan replaces physical inspection, measurement, calibration or functional verification.
Before repairs
Identify the vehicle accurately, stabilise battery voltage and scan all accessible systems with suitable equipment. Save the full report before clearing anything.
Review current, history and communication DTCs in context. Note warning lamps, system status, customer complaints, prior repairs and modules that do not communicate. A code description is a starting point—not a diagnosis or instruction to replace the named component.
During the repair
Use current service information to decide which faults must be resolved before calibration or programming. Inspect wiring, connectors, brackets, sensor covers, vehicle geometry and related systems.
Record modules disconnected or replaced, additional damage and changes to the agreed repair plan. Avoid repeatedly clearing codes that could preserve useful evidence.
After repairs
Complete required programming, coding, initialisation and calibration in the specified order. Then perform a full post-scan and compare it with the original report.
Investigate new, returning or unresolved codes. Confirm module communication and complete manufacturer-specified functional checks or road tests. A clean post-scan does not prove sensor aim, and a stored history code does not automatically mean the repair failed.
Reporting
Retain tool identification, software version, VIN, date, odometer and reports. Explain unresolved codes, limitations and subcontracted tasks clearly. If a module could not be accessed, record that rather than implying the vehicle was fully scanned.
Key point
The value of scanning lies in comparison and interpretation: establish the starting condition, guide the repair and provide evidence of the final electronic state.