Scan Tool Testing and Procedures

DATA STREAM INFORMATION
There are several access modes through which data may be extracted from the ECM via the J1962 connector using the relevant scanner.

Parameter Identification (PID) - Access (Mode 01)

Generic OBD II PID List:

- X = Freeze Frame PID
- Open = Open loop, have not satisfied conditions for closed loop.
- Closed = Closed loop using O2S(s) as feedback for fuel control.
- OP DRV = Open loop due to due to driving conditions (heavy acceleration).
- OP SYS = Open loop due top vehicle system fault.
- CL O2S = Closed loop fuel control, but fault with O2S sensor(s).


Freeze Frame Data - Access (Mode 2)

Freeze Frame Data Access List:

Freeze Frame Data allows access to emission related data values from specific generic PIDs. These values are stored the instant 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 will remain 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 will overwrite any previous data and freeze frame will not be further overwritten. When a DTC associated with the freeze frame is erased or a PCM memory reset is performed, 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.


Generic Scan Tool:
Refer to the scan tool manufacturer's instructions to access Freeze Frame Data (Mode 02).


Oxygen Sensor Monitoring - Access (Mode 05)





The Oxygen Sensor Monitoring Test Results allows access to the On-Board sensor fault limits and actual values during the test cycle. The test cycle has specific operation conditions that must be met (engine temperature, load, etc.) for completion. This information helps to determine the efficiency of the exhaust catalyst. Listed in the image above are the tests and test identification numbers that are available.





The codes in the image above are to be confirmed.