Freeze Frame Charts
Freeze Frame Data allows access to emission-related values from specific generic parameter identification (PIDs). These values are stored when an emission-related DTC is stored in continuous memory. This provides a snapshot of the conditions that were present when the DTC was stored. Once one set of freeze frame data is stored, this data remains in memory even if another emission-related DTC is stored, with the exception of misfire or fuel system DTCs. Once freeze frame data for misfire or fuel system DTC is stored, it overwrites any previous data, and freeze frame data is no longer overwritten. When a DTC associated with the freeze frame is erased or the DTCs are cleared, new freeze frame data can be stored again. In the event of multiple emission-related DTCs in memory, always note the DTC for the freeze frame data.
Freeze Frame Data Table
| Acronym | Description | Measurement Units |
|---|---|---|
| AAT | Ambient Air Temperature | Degrees |
| APP_D | Accelerator Pedal Position D | % |
| APP_E | Accelerator Pedal Position E | % |
| APP_F | Accelerator Pedal Position F | % |
| BARO | Barometric Pressure | kPa |
| CATTEMP11 | Catalyst Temperature Bank 1, Sensor 1 | Degrees |
| CATTEMP21 | Catalyst Temperature Bank 2, Sensor 1 | Degrees |
| CLRDIST | Distance Since Last Code Cleared | Km |
| ECT | Engine Coolant Temperature | Degrees |
| EQ_RAT | Commanded Equivalence Ratio | Unit |
| EQ_RAT11 | Lambda Value Bank 1, Sensor 1 | Unit |
| EQ_RAT21 | Lambda Value Bank 2, Sensor 1 | Unit |
| EVAPPCT | Commanded Evaporative Purge | % |
| EVAPVP | Evaporative System Vapor Pressure | Pa |
| FLI | Fuel Level Input | % |
| FUELSYS1 | Open/Closed Loopl | OL/CL/OL DRIVE/OL FAULT/CL FAULT |
| FUELSYS2 | Open/Closed Loop2 | OL/CL/OL DRIVE/OL FAULT/CL FAULT |
| IAT | Intake Air Pressure | Degrees |
| LFT1 | Long Term Fuel Bank 1 | % |
| LFT2 | Long Term Fuel Bank 2 | % |
| LOAD | Calculated Load Value | % |
| MAF | Mass Air Flow Rate | g/s |
| MAP | Manifold Absolute Pressure | kPa |
| O2S11 | Bank 1 Upstream Oxygen Sensor (11) | Volts/mA |
| O2S12 | Bank 1 Downstream Oxygen Sensor (12) | Volts |
| O2S21 | Bank 2 Upstream Oxygen Sensor (21) | Volts/mA |
| O2S21 | Bank 2 Sensor 1 Current | Current |
| O2S22 | Bank 2 Downstream Oxygen Sensor (22) | Volts |
| RPM | Engine RPM | RPM |
| RUNTM | Run Time | Seconds |
| SFT1 | Short Term Fuel Bank 1 | % |
| SFT2 | Short Term Fuel Bank 2 | % |
| SPARKADV | Spark Advance | Degrees |
| TAC_PCT | Commanded Throttle Actuator | % |
| - | Absolute Throttle Position | % |
| TP_REL | Relative Throttle Position | % |
| VS | Vehicle Speed | km/h-mph |
| WARMUPS | Number Of Warmups Since Code Cleared | Units |
Some unique PIDs are stored in the Keep Alive Memory (KAM) of the PCM to help in diagnosing the root cause of misfires. These PIDs are collectively called misfire freeze-frame (MFF) data. These parameters are separate from the generic freeze-frame data that is stored for every MIL code. They are used for misfire diagnosis only. The MFF data could be more useful for misfire diagnosis than the generic freeze frame data. It is captured at the time of the highest misfire rate, and not when the DTC is stored at the end of a 1,000 or 200 revolution block. (Generic freeze-frame data for misfire can be stored minutes after the misfire actually occurred).
- MFF PIDs are supported on all vehicles but may not be available on all scan tools because enhanced PID access may vary by scan tool manufacturer.
Misfire Freeze-Frame PIDs
| PID Name | Description | Measurement Units |
|---|---|---|
| MFF RPM | Engine RPM at the time of misfire | RPM |
| MFF LOAD | Engine load at the time of misfire | % |
| MFF VS | Vehicle speed at the time of misfire | km/h-mph |
| MFF IAT | Intake air temperature at the time of misfire | Degrees |
| MFF SOAK | Engine-off soak time at the time of misfire | Time |
| MFF RNTM | Engine running time at the time of misfire | Time |
| MFF EGR | EGR DPFE sensor at the time of misfire | Volts |
| MFFTP | Throttle Position at time of misfire | Volts |
| MFF TRIP | Number of driving cycles at the time of misfire (at least one 1,000 rev block) | No. TRIPS |
| MFF PNP | 1= in drive during the time of misfire | Mode |
| MPL RN | 1= Misfire wheel profile learned in KAM | Yes/No |