Mechanic Guides
Automotive Diagnostic Report Template: Separate Findings from Recommendations
An original diagnostic report template with a fictional worked example separating observations, conclusions and proposed work.
Published · 4 min read
Quick answer
An automotive diagnostic report should tell the next reader what the technician observed, what the evidence supports, and what still needs to happen. Keep measured findings separate from suspected causes and proposed work. The original template below is a communication record for a shop, not a replacement for its repair order or vehicle-specific service procedure.
Write for the person receiving the case
A service advisor needs a clear explanation of the concern, the work completed and the next decision. A technician continuing the case also needs test conditions and evidence references. Give both readers a short summary followed by the supporting detail. Avoid a long chronological account that hides the unresolved question.
Start with one sentence that states the present outcome. For example: Concern reproduced; cause not yet established; additional testing proposed. That sentence is more useful than diagnosis completed when the repair decision is still open.
Copy this diagnostic report template
Use a case identifier that links to the shop's existing records. Keep customer contact details in the appropriate shop system rather than duplicating them in every exported worksheet.
- Case / repair-order reference:
- Vehicle and configuration:
- Report date and technician:
- Customer concern in the customer's words:
- Conditions under which the concern occurs:
- Technician-confirmed observation:
- Work performed and applicable procedure references:
- Results, units, test conditions and evidence filenames:
- Interpretation supported by those results:
- Suspected causes that remain unconfirmed:
- Proposed next test or work:
- Authorization status and person responsible for follow-up:
- Vehicle state at handoff and any incomplete work:
- Verification performed and remaining limitations:
For individual measurements, the electrical test comparison includes a more detailed measurement record. Use the report to summarize and link that evidence, rather than copying every trace or photograph into the summary.
Example: a useful report can have an unresolved outcome
The following is an invented documentation example, not an actual customer case or a repair procedure.
Concern: Customer reports an intermittent hesitation after warm-up.
Observation: In this fictional case, the technician observed one hesitation after warm-up during light acceleration. Observation note OBS-01 records the event and conditions; no component cause has been established.
Work performed: Customer interview recorded as INTAKE-01 and symptom observation as OBS-01. No component test has been completed in this example.
Interpretation: The concern was reproduced. The available evidence does not yet establish a failed component.
Recommendation: Continue with the applicable symptom-diagnostic procedure. Record the next test and the approval status before proceeding.
Handoff: Diagnosis remains open. The receiving technician should read INTAKE-01 and OBS-01, confirm that no component test is recorded, and enter the selected symptom-procedure reference and next test in PLAN-01 before work resumes. These identifiers are fictional placeholders, not downloadable evidence.
Notice the distinction between confirming the symptom and confirming its cause. A report should not turn one into the other.
Replace conclusions that hide missing evidence
Instead of writing sensor bad, identify the finding and its applicable comparison source. If the evidence does not establish that conclusion, label the sensor as a hypothesis and name the next test.
Instead of writing customer declined, identify which proposed work remains unapproved and reference the shop's authorization record. This template does not establish legal authorization requirements; follow the shop's applicable process.
Instead of writing fixed, describe the verification that was actually completed. If the original condition could not be recreated, say so. A clear limitation gives the next reader a more accurate starting point than an unsupported completion label.
Review before sharing
Read the summary without the rest of the case in front of you. Can you tell which statements are observations, which are interpretations and which are proposals? Then open each evidence reference and check that it belongs to the correct case.
Use the diagnostic process checklist to track the work; use this report to communicate its outcome. To discuss your shop's needs for guided, documented diagnostic work, request STEP early access.