CrankKey diagnostic help
Freeze-Frame Data: Plain-English Field Guide for CrankKey Diagnostic Help
Freeze-frame data is a snapshot of vehicle operating conditions recorded when a fault is detected. A saved record can include a diagnostic trouble code and the parameter values returned for that snapshot.
Reading a record
Start with the label and unit
Read each field label together with its displayed unit. Keep the value with the code and source shown in the scan record, and use the vehicle service manual for model-specific definitions.
This quick reference explains commonly cited labels and their general diagnostic role. It does not claim that the list is complete or mandatory, set pass/fail ranges, or replace vehicle-specific definitions from the service manual.
Quick reference
Common fields, labels, and units
These are commonly cited fields and label conventions, not a complete or universally mandatory list; availability and units may vary by vehicle.
- Engine load
- A calculated measure of the engine’s operating demand at the snapshot; the calculation is vehicle-specific.
- %
- Short-term fuel trim
- The controller’s immediate fuel correction in response to air/fuel feedback at capture.
- STFT
- Long-term fuel trim
- The learned, longer-term fuel correction retained from prior air/fuel feedback.
- LTFT
- Engine coolant temperature
- The coolant temperature reported by the engine controller’s temperature circuit at capture.
- ECT
- Fuel pressure
- The fuel-system pressure reported for the snapshot; its measurement point and unit depend on the vehicle.
- varies
- Intake manifold absolute pressure
- The absolute pressure reported in the intake manifold at capture; use the vehicle’s unit and sensor definition.
- MAP
- Engine speed
- Crankshaft rotation speed at capture, reported as revolutions per minute.
- RPM
- Vehicle speed
- The road speed reported by the vehicle at capture; the displayed unit depends on the scan record.
- varies
- Timing advance
- The ignition-timing advance value reported for the snapshot; exact definition and units are vehicle-specific.
- reported
- Oxygen-sensor voltage
- Voltage reported by an oxygen-sensor circuit at capture; sensor type and vehicle strategy determine how to read it.
- V
- Temperature
- Degrees Fahrenheit / degrees Celsius
- °F/°C
- Percentage
- Percent
- %