Inspection & Diagnosis: the full procedure
Verify the reported concern, perform a multi-point inspection, and document findings with measurements and codes so recommendations are evidence-based.
- Applies to: Technician.
- Frequency: Every repair order.
- Scope: Covers the diagnostic process and documentation. Specific technical test procedures defer to OEM service information and ASE-qualified technicians.
What you need
- Scan tool
- Multi-point inspection checklist
- Measuring tools (tread, brake, multimeter)
- OEM service information
- RO / photo documentation
The procedure, step by step
- Verify the concern — Reproduce the customer’s stated symptom before troubleshooting so you’re solving the real problem, not an assumption.
- Pull & record codes — Retrieve and document any diagnostic trouble codes and freeze-frame data as the starting point for diagnosis.
- Run the multi-point inspection — Inspect major systems — fluids, brakes, tires/alignment, lighting/electrical, steering/suspension, belts & under-hood — per the ASE-aligned checklist.
- Measure, don’t eyeball — Record actual measurements (tread depth, brake pad thickness, fluid condition) so recommendations are defensible.
- Follow OEM diagnostic procedures — Use OEM service information to confirm the fault before condemning a part.
- Document findings with evidence — Note each finding on the RO with codes, measurements, and photos of the failed condition.
- Categorize by urgency — Separate the original concern, safety items, and recommended maintenance so the advisor can build a clear estimate.
- Hand off to the advisor — Provide the advisor a complete, prioritized findings list to turn into a written estimate.
Quality check before you finish
- Original concern reproduced and confirmed.
- All trouble codes recorded.
- Multi-point inspection completed across all systems.
- Measurements logged, not just pass/fail.
- Photos attached for each significant finding.
- Findings prioritized (concern / safety / maintenance).
- Diagnosis traced to OEM-confirmed cause.
This is a free, source-anchored standard operating procedure (SOP) you can print and hand to staff. It documents the work sequence for a Auto Repair Shop business — not safety or regulatory rulings, which defer to the cited authorities, the applicable code, and your own health-and-safety plan. Open the tool above to print it, toggle ink-saver, or (with a free ToolFluency Business account) edit it to match your own workflow.
Sources
- ASE — Multi-Point Inspection Standards (ase.com)
- ALLDATA / Mitchell1 ProDemand — OEM Diagnostics (alldata.com)
- AAA Approved Auto Repair — Inspection Requirements (aaa.com)
About Free Inspection & Diagnosis SOP for Auto Repair Shops
Free printable inspection & diagnosis SOP: verify the concern, run a multi-point inspection, record codes and measurements, and document evidence-based findings.
How to use
- Read the full procedure top to bottom before the work — the SOP runs in order and each step builds on the last.
- Toggle Ink-saver (black & white) for a cheaper mono print for the binder; leave it off for the full-color version.
- Click Print SOP to print or save as PDF. Print one per crew, laminate it for the binder, or attach it to the job in your scheduling system.
- Train new hires on it and have staff sign off. Found something out of date? Use the feedback link — flagged SOPs are re-researched against the source list.
Frequently asked questions
Why measure instead of just marking pass or fail?
Recorded numbers (tread depth, pad thickness) give the customer proof and let you track wear over time — they also defend the recommendation if it’s questioned.
Do techs need to document an obvious diagnosis?
Yes. Every finding should tie to a code, measurement, or photo. "Obvious" diagnoses that skip documentation are the ones that turn into disputes and comebacks.
Part of ToolFluency’s library of free online tools for Printables. No account needed, no data leaves your device.