The pre and post scan has become the single most important document in collision repair. More than the estimate. More than the parts invoice. When a repair is questioned -by an insurer, by a customer, by a lawyer -the scan report is the first thing anyone asks for. Shops that scan every vehicle, every time, have a defensible record of what was found and what was fixed. Shops that don't are flying blind and hoping nothing goes wrong.
What a Pre-Scan Actually Shows You
A pre-repair scan is performed before any repair work begins and captures every fault code stored in the vehicle's control modules. This matters for two reasons. First, it identifies pre-existing conditions -issues that were present before the vehicle arrived at your shop. Second, it reveals hidden damage that didn't show up on a visual inspection. ADAS-related fault codes often appear after even moderate impacts, indicating sensors that moved or sustained internal damage that's invisible from the outside.
What a Post-Scan Proves
A post-repair scan, performed after all repair work and calibrations are complete, confirms that the vehicle is leaving your shop with a clean bill of health -no active fault codes, all systems operating correctly, all calibrations verified. This document is your proof that the repair was done right. In the event of a subsequent accident or complaint, it's the difference between a defensible record and an indefensible one.
The Supplement Connection
Pre-scans also drive supplements. When a scan reveals ADAS-related fault codes or required calibration procedures that weren't in the original estimate, you have documented evidence to support a supplement request. Insurers who might question a calibration charge are hard-pressed to deny it when the pre-scan shows the fault codes and the OEM procedure requires calibration to resolve them.
Making Scans Standard Practice
The shops that scan every vehicle -not just the ones that seem to need it -are the shops with the cleanest records and the fewest comebacks. Build pre and post scans into your intake and delivery process as non-negotiable steps. The cost of the scan is a fraction of the liability it protects against and the supplements it supports.