Before any intervention that could remove information, save the exact code, its status, accessible freeze-frame data and your own notes. Keep the vehicle’s stored information, current readings and your recollection separate. Clear codes only after repair.
Freeze frame gives context, not a complete diagnosis
A freeze frame is a snapshot of parameters stored by the control unit when a fault is detected. It is neither a recording of your journey nor proof that a particular part needs replacing.
First identify the code associated with the displayed values. If several faults appear, do not assume that the same figures belong to all of them. Keep the screen heading visible too: a screenshot cropped to a single temperature loses much of its usefulness.
The practical aim is straightforward: give the technician readable information to help select the next checks. You do not need to understand every abbreviation before saving the report.
Stored data, live readings and recordings have different jobs
Label each document clearly. A reading taken on your driveway after a journey is not a measurement from the incident. This simple distinction prevents comparisons between information collected for different purposes.
Car Scanner separately documents recording viewed values and exporting CSV/BRC files. This cannot reconstruct an earlier event. Menus may change with the application version.
| Document | Question it helps answer | Suggested filename |
|---|---|---|
| Accessible freeze-frame data | What context is associated with the stored fault? | 01-code-freeze-frame |
| Live reading while parked | What was displayed during this particular check? | 02-reading-date-time |
| Recording started in the application | What was saved during this session? | 03-session-recording |
| Your driving notes | What did you notice, and when? | 04-symptoms-context |
An editorial filing suggestion, not a test result or a guaranteed feature list.
Prepare a useful file before the appointment
Start with the vehicle safely parked. Do not handle your phone while driving or deliberately provoke a fault to improve a report. A red warning, overheating, severe shaking or dangerous loss of power makes safety and assistance more important than collecting data.
Follow the connection instructions. If a freeze-frame screen is available, save it along with codes and their displayed statuses. Take multiple screenshots if needed, keeping parameter names and units visible. Check that the saved files open without starting a clearing operation.
Add the consultation date and dashboard mileage separately. Do not present that date as the time the fault occurred unless you actually know it. For an intermittent event, record what you remember reliably: a cold start, a journey already underway, waiting at traffic lights or accelerating.
- Vehicle model, model year, fuel type and known engine version; do not guess missing details.
- Every displayed code and its original status, without an approximate translation.
- Available values with their original screen labels and units.
- Actual symptoms, frequency and driving conditions you remember.
- Recent servicing, refuelling or repairs, with dates where available.
- Application name and version, plus any observed connection difficulty.
Send the full VIN only through an appropriate private channel. Hide registration and contact details before posting a screenshot publicly.
Read the figures without jumping to a conclusion
Check the units first: °C and °F are not directly comparable, nor are km/h and mph. Copy values exactly. If you convert a value for your garage, keep the original alongside it.
A temperature alone does not condemn a thermostat. Engine speed alone does not reconstruct your accelerator input. A better question is whether the values make sense together and in relation to the recorded fault on this particular engine.
Avoid a universal green/red chart for every vehicle. Write ‘not displayed’ for a missing value, not zero. Flag a surprising reading without changing the report to make it seem plausible. Uncertain information should remain visibly uncertain.
A manufacturer example shows why context matters
Mazda3 2010–2011, 2.0 LF: North American bulletin 01-021/13 uses stored temperatures to assess a P0128 route. Model year, transmission and VIN require checking.
Evidence level: official manufacturer documentation, not an OBDPhone® test of this engine. This example establishes neither fault frequency nor reading compatibility. A matching model name does not justify applying it to a European vehicle.
The lesson for your own file is to preserve the original information so a repairer can check a documented possibility. Sending only ‘thermostat fault’ unnecessarily removes that opportunity.
An empty screen or an already-cleared code: what next?
Clearing can remove freeze-frame data. Save it first and clear codes only after repair.
If nothing is displayed, describe the exact outcome: no connection, readable codes but an empty screen, or a section you cannot find. These situations need different checks. A missing document does not show that the vehicle has no problem.
If you have already cleared the codes, tell the garage when and provide any saved screenshots. Do not recreate a supposed history from a new live reading. Factual notes and repair invoices are still useful; ask the technician what else can safely be collected.
Prepare for diagnosis with OBDPhone®
On a compatible vehicle, OBDPhone® reads generic engine and emissions fault codes and available engine data, with clearing only after repair. Freeze-frame access and displayed fields depend on the vehicle and application; they are not guaranteed for every model.
ABS, airbags, traction batteries, coding, programming and manufacturer-specific functions are not guaranteed. Before buying or when troubleshooting a reading, use the compatibility checker, then contact support@obdphone.com with vehicle details and the relevant screen.
Sources last checked: 23 September 2026. The Mazda bulletin is dated 31 July 2013 and is a historical example requiring confirmation for the exact vehicle. This article claims no OBDPhone® test, customer screenshot or observation from the 520-model database.
Frequently asked questions
The essential answers.
Does freeze frame identify the part to replace?+
No. It provides context to consider alongside the code, symptoms and checks on the exact vehicle.
Do I need to drive to save this information?+
Read accessible information while parked and follow the relevant instructions. Do not provoke a fault or operate the application while driving.
What if the freeze-frame section is empty?+
Save any readable codes and the exact message. Give support your vehicle details and application version; an empty screen does not prove there is no fault.
Can I send only a temperature screenshot?+
Include the associated code, screen name and units. Say whether it was stored data or a live reading, and add the symptoms.
This guide supports an initial understanding. It does not replace the vehicle manual, manufacturer safety instructions or an assessment by a qualified professional.
Primary sources
Reviewed to verify the facts and show why procedures depend on the vehicle.