Permanent trouble code
Permanent trouble code: Freeze frame is a snapshot of selected operating parameters when a DTC sets and should be preserved before clearing faults. The page also includes a worked example and measurement sequence.
Technical frame
Permanent trouble code: Freeze frame is a snapshot of selected operating parameters when a DTC sets and should be preserved before clearing faults. The page also includes a worked example and measurement sequence.
The technical values here expose the standard, protocol or physical relationship directly; model-specific service values are linked through the matching model/variant dossier.
The goal is not only to define the term but to let the reader calculate and interpret what the data means in a scan, scope or physical test.
Concrete technical facts
- Freeze frame is a snapshot of selected operating parameters when a DTC sets and should be preserved before clearing faults.
- A pending DTC means a monitor has detected a fault condition but confirmed criteria may not yet be complete.
- For certain emissions faults, a permanent DTC is not erased simply by a clear command; successful monitor conditions are required.
- Readiness indicates whether an OBD monitor has completed; “complete” does not automatically mean every related component is healthy.
- Live data is current state and scan-tool polling rate can miss fast events.
- DTC status, freeze frame, companion codes and live data are complementary evidence.
Worked example
- Example: if P0171 freeze frame occurs at 780 rpm/low load, idle/vacuum-leak causes become more relevant; under high load, fuel-flow/pressure causes deserve more weight.
Measurement and verification sequence
- Capture DTC status and freeze frame before clearing.
- Record readiness and monitor conditions.
- Set data sampling strategy around the critical signal.
- After repair, confirm that the relevant monitor runs again.
Fault-separation logic
- Is a valid command present and are power/ground/network healthy?
- Does feedback follow the command?
- Does an independent physical measurement confirm the output?
- Is the fault limited to a specific temperature/load/speed condition?
- Does the result remain stable when the original condition is repeated after repair?
Technical sources
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Model-specific real technical data · Measurement references · Technical diagnostic atlas