A technician is using a scan tool to diagnose a vehicle with a 'Check Engine' light illuminated. After retrieving a DTC P0301 (Cylinder 1 Misfire Detected), the technician accesses the 'Freeze Frame Data'. What information does Freeze Frame Data provide that is particularly useful for diagnosing this intermittent misfire?
- AEngine operating conditions at the exact moment the DTC was set.
- BReal-time sensor readings for all engine parameters.
- CA historical log of all previously cleared diagnostic trouble codes.
- DRecommended repair procedures for the specific DTC.
Show answer & explanationAnswer & explanation
Correct answer: A. Engine operating conditions at the exact moment the DTC was set.
Freeze Frame Data is a snapshot of various engine operating parameters (such as engine RPM, coolant temperature, vehicle speed, fuel trim, etc.) captured by the Powertrain Control Module (PCM) at the precise moment a diagnostic trouble code (DTC) is set. This information is invaluable for diagnosing intermittent issues like misfires, as it helps recreate the conditions under which the fault occurred.
Why the other options are wrong
- B. Real-time sensor readings are available in 'Live Data' or 'Data Stream', not Freeze Frame.
- C. Historical DTCs are usually found in a separate 'History' or 'Permanent' DTC menu, not Freeze Frame.
- D. Recommended repair procedures are found in service information, not directly on the scan tool's Freeze Frame Data.
Freeze Frame Data
A snapshot of engine operating conditions (e.g., RPM, coolant temp, speed, fuel trims) recorded by the PCM at the exact moment a Diagnostic Trouble Code (DTC) is set, providing crucial context for fault diagnosis.
- Snapshot of conditions when DTC set.
- Invaluable for intermittent faults.
- Available via scan tool.
Memory trick: Freeze Frame: a snapshot of the engine's 'crime scene' when the code was born.