Correlating Freeze Frame records with a DTC?

[GaryDoug]

I have the GM enhanced option, if that makes a difference. When I retrieve the freeze frame data frames, I don't see any reference to the corresponding DTC. How can I tell to which DTC the frame is associated?

[GaryDoug]

OK, now I see. There is NO real Freeze Frame data available, even though it exists and should be easy to extract. How is it that you created your own term for Freeze Frame apart from the industry standard? Your feature only returns a list of the supported PID's data at the CURRENT time that you click on the button, not at the time that the DTC was set. That is not very useful. Does anyone with PPE have an answer to this?

[Weston@PPE]

We have not invented our own freeze frame data, we use the OBD-II standardized methods of retrieving freeze frame information from a vehicle (mode $02). What vehicle are you using this on exactly?

I am not aware of any way to determine which DTC the freeze frame data corresponds to.

[GaryDoug]

Vehicle: 1998 Pontiac Bonneville V6 3.8

FYI Freeze Frame data is 'frozen" in time hence the name. Every time I click on the Read FF button, the numbers are updated with new values, including many that are changed from the prior click! That is NOT freeze frame data since it changes and since it is way more data than expected for a freeze frame set. What you have done is to simply capture real time data whenever the button is clicked.

See an OBDWiz screen for an example of the type used according to J1979 (mandated) Mode 02. The associated DTC is given in the set of data returned.
Per J1979: "Service $02 PID $02 indicates the DTC that caused the freeze frame data to be stored. If freeze frame data is
not stored in the ECU, the system shall report $00 00 as the DTC." In this vehicle the freeze frame DTC is stored and is displayed correctly by the OBDwiz program, why not yours?

To go farther yet, for J2190, the following is an example of Enhanced Mode 12 FF request and responses from a 98 Bonneville V6:

12 00 FF FF            'request for frame 0
52 00 00 02 01 22   '1st line of response including the DTC of P0122
52 00 00 03 01 00
52 00 00 04 05
52 00 00 05 63
52 00 00 06 7F
52 00 00 07 7F
52 00 00 0B 0A
52 00 00 0C 0A 25
52 00 00 0D 00
52 00 00 10 01 5F
52 00 00 11 00
52 00 11 93 00 AA
52 00 11 9E 93
52 00 12 35 00 00
52 00 12 36 00 00
52 00 12 37 00
52 00 12 38 00
52 00 12 39 00
52 00 12 51 EE
52 00 00 02 01 22    'last line of response for frame 0, including a repeat of the P0122 DTC


What I see from your program is instead a list of ALL the available PID's in real time (at the instant I clicked)

[Weston@PPE]

I just tested this on my car, it worked as expected and gave the data from when the code was set. It did not update or change if I read the same frame again. I'll see if we can't get a similar vehicle to yours to test with.

[GaryDoug]

This also gives the same error on a 98 Pontiac Firebird V8, engine off or on. Keep in mind that the engine must be running to get changing readings for many PID's. Note that there should only be 18 total mandated and enhanced PID's in the FF for the 98 Bonneville V6. On my screen it shows many, many more than that and many show invalid readings

[BrianP]

This also gives the same error on a 98 Pontiac Firebird V8, engine off or on. Keep in mind that the engine must be running to get changing readings for many PID's. Note that there should only be 18 total mandated and enhanced PID's in the FF for the 98 Bonneville V6. On my screen it shows many, many more than that and many show invalid readings

Would you be able to send a level 9 techlog to support so we can see what is going on here?

[GaryDoug]

Absolutely, I will do anything that is needed. Just tell me what to do. I am not familiar with your logs.

[Cody@PPE]

To get a techlog start by going to Help>Debug Options>Debug Level 9.  Then pull the freeze frame data.  Then go to Help>Debug Options>Save Tech Log and email that tech log support@palmerperformance.com

[GaryDoug]

I did as you asked, but have not received a good reply to this topic. The issue, to remind you, is that the freeze frame information is missing the DTC# that caused the freeze frame to be stored in the first place. Without that information, the user cannot link the data to a specific DTC if there is more than one DTC. The causing DTC can be found using a Mode $12 frame request. I am pretty sure you are already using this. The result is in the very first line of the response at location 0002. See my post above from July 4th. One simple solution to this would be to simply include that "PID" 0002 with the freeze frame data. And even if you do not use the Mode 12 method, it is still available using SAE Mode 02 PID 02.
Other less (and more) capable programs provide this information. You can clearly see that the OBDWiz program provides it.