Compare Pre-Repair and Post-Repair Scan Charges and Reports

The Short Answer

A pre-repair scan and a post-repair scan are two separate operations, even when a shop prices them as one charge. To compare quotes fairly, check three things in each one. It should include both scans. It should name the systems each scan covers. It should promise a written report for each scan. Diagnosing a fault that a scan finds and calibrating sensors or cameras are different jobs from the scan itself. Ask whether each one is included or billed separately, and approve it separately.

Some terms explained:
• A scan connects a scan tool to the vehicle's diagnostic port. The tool talks to the control modules, which are the computers that run systems such as airbags, brakes, steering and driver-assistance features. It reads any stored diagnostic trouble codes (DTCs).
• The pre-repair scan is done before disassembly. It records the condition the vehicle arrived in.
• The post-repair scan is done after the work. It checks for codes that remain or appeared during the repair, and confirms that the modules respond.
• A DTC means a module detected a condition outside its expected range. It points to an area to investigate. It does not confirm that a part has failed.

What Each Scan Report Should Show

• Vehicle identity: VIN, year, make and model, matching your estimate or repair order.
• Date and time: so the pre-repair report clearly comes before the repair and the post-repair report after it.
• Systems covered: which modules were checked, and which did not respond or could not be read.
• Codes found: each code listed, with its status if the tool reports one.
• Who performed it: the shop itself or an outside scanning provider.
• Supporting notes or photos: TOPDON training manager Haakan Light describes adding dashboard photographs to pre-scan reports to document a customer's concerns, such as warning lights.
• Preparation and incomplete results: Light also explains that voltage conditions can affect code retrieval. Ask whether the report notes how the vehicle was prepared and whether any module communication or code retrieval was incomplete.

Separate Charges vs. a Bundled Charge

Repairer Driven News reported in 2018 that some estimates listed pre-scans and post-scans as separate charges, while others used one combined charge. The same reporting noted that a missing scan line on an estimate did not necessarily mean the scan was skipped. Neither format proves what work was done; the written scope and the reports do. The prices in that reporting are years old and are not a guide to current pricing.

Criterion	Separate line items	Single bundled charge
Visibility	Each scan is priced and described on its own	One price; the included operations must be spelled out in writing
If the repair stops early	Easy to see what you owe after only the pre-scan	Ask how the bundle is billed if the repair is not completed
Line-by-line estimate review	Matches item-by-item comparison	Needs a written list of what the bundle includes
Main risk	Provider or setup fees listed elsewhere and missed in the total	Follow-up work assumed to be included when it is not
Best fit	You want to track each operation or compare insurer and shop estimates	You only want one total and the scope is clearly written

Neither structure is better in itself. Choose the quote whose written scope you can check. When comparing two shops, put both quotes on the same basis: two scans, two reports and any provider fees. Then compare the totals.

Illustrative example with hypothetical numbers, not market prices: Shop A lists a $110 pre-scan and a $110 post-scan, for $220 total. Shop B quotes a $190 scan bundle. Shop B is cheaper only if its bundle includes both scans, a report for each, and no separate provider fee. If the bundle covers only one scan, or a fee appears elsewhere on the estimate, the comparison changes. With either shop, get separate approval terms for any diagnosis or calibration the scan charge does not include.

Work a Scan Charge May Not Cover

A scan finds codes. Working out why a code is present is fault investigation, or diagnosis, which is further work beyond reading codes. Calibration is also separate. It means aligning or resetting cameras and sensors for advanced driver-assistance systems (ADAS) after repairs or part replacement. For each of these operations, ask the shop three things: what would trigger it, what it delivers, and how it is priced. Ask the shop to get your approval before doing it. Which systems need scanning or calibration depends on the vehicle's make, model year and equipment. Ask the shop to name the manufacturer information that applies to your VIN rather than relying on a general rule.

How to Compare the Two Reports

• 1. Confirm both reports show the same VIN and vehicle details.
• 2. Check that the timestamps place the pre-scan before the repair started and the post-scan after it finished.
• 3. List every code and every unavailable system in the pre-repair report.
• 4. For each item, record the shop's explanation, for example collision-related, already present before the collision, or needing further investigation.
• 5. Link each item to an action you authorized on the estimate or repair order.
• 6. In the post-repair report, mark which items were cleared, which remain, which are new, and which systems still do not respond.
• 7. Get any unresolved follow-up recorded in writing.

Do not treat a clean post-repair scan as proof that every repair is correct. Do not treat a remaining code as proof that a repair failed. Some conditions do not set codes, and some codes may come from problems that existed before the collision. Instead, ask what work supported the provider's conclusion, such as a calibration record or a follow-up scan after a specific repair.

Authorization Worksheet

Item	What to record
VIN	Full VIN, matching the repair order
Pre-repair scan	When it will be done and which systems it covers
Post-repair scan	When it will be done and which systems it covers
Manufacturer reference	The position statement or repair procedure the shop cites for your vehicle
Provider	The shop itself or a named outside provider
Deliverable	The report you will receive for each scan
Charge	Amount, and whether it is separate or bundled
Fault investigation	Separate row: trigger, deliverable, price, approval
Calibration	Separate row: trigger, deliverable, price, approval
Other follow-up	Separate row for each proposed operation

Questions to Ask Before You Approve

• Does this price include both a pre-repair and a post-repair scan?
• Will I receive a report for each scan, and what will it show?
• Which systems will be scanned, and how will you record any that cannot be read?
• Who performs the scan, and are there provider fees not shown in this line?
• If the repair is canceled after the pre-scan, what do I owe?
• What diagnosis, calibration or other follow-up is excluded, and how will you ask for my approval before doing it?
• Which manufacturer information are you following for this vehicle?