More uses for SSM2

[cdvma]

If only I had more time.....

I know the feeling.

Problem is that I only got one responce at all. I'm guessing that I don't have the right memory addresses. I might have to spy the "other" software's serial communication to see what addresses its polling.

[cboles]

...sorry i don't have more time to adequately explain this right now. In the Subaru ROM, there is a table which maps DTC codes to specific bit fields in RAM. You can use this table to figure out where all of the DTC codes are stored. You can also use it to make certain DTC codes "dissapear" if you like, by replacing their DTC code with a special sequence, thereby mapping them to "nothing"

[crazymikie]

Chris,

As far as I can tell, these values are SSM 'addresses' so they should be consistent across different cars. I'm not sure why they aren't returning anything for you.

I think I know the table that Colby is talking about- it basically takes each SSM address and uses it as an index into the table. The value for each entry is an address in memory or ROM- some of these addresses are 'valid' data, whereas some of them are just 0x00 or 0xFF. I verified this by using the SSM data that was posted and saw a pattern where the unsupported addresses for my ECU returned bogus data all of the time, whereas the supported ones referenced values in RAM.

I think what Colby was saying was by changing the value for some of these CEL addresses so that the value it references is 0x00, then the CEL should disappear. I was trying how to figure out the logic that was being used to trip or not trip the CEL, and modify the limits so that the CEL wouldn't happen. Seems like Colby's way is a lot less work.

Let me know if you have any questions. You around in MA or are you back in NY?

Mike

[cdvma]

So did you poll the same addresses in the dtc file? I get the lookup table idea so I'm assuming that I just have the incorrect addresses for my ECU.

I'm in NY and I'll be back for breaks (Thanksgiving, Christmas, March break) but this is my last year here (ugh...almost done...).

[crazymikie]

Yup. You should be able to poll the same address. One of the major benefits of the SSM is that the addresses for certain data and DTCs can be made consistent across different model cars- it's basically a layer of indirection.

I'm still not sure why you can't poll those addresses- have you tried the program I posted about? If you aren't getting a response, it almost seems like the command is malformed.

Mike

[cdvma]

Well I got a responce from one of them and I'm running SSP2 in other places so I know I'm not mis-communicating. Its very possible the serial cable bumped out again :rolleyes: since that happened before. I guess that I'll give it another go.

Can someone else run the same addresses and lemme know what they get? Obviously it would help to have an active CEL.

[cdvma]

So I was a dope and I had a glitch in the little test program I wrote to pull the dtc addresses...got that taken care of.

I don't remember exactly remember what I've got in there but I know I have the following:

Current:
P0102 MAF Low input

Historic:
P0102 MAF Low input
P0301 Cyl #1 misfire
P0302 Cyl #2 misfire
P0303 Cyl #3 misfire
P0304 Cyl #4 misfire

There might be one more historic code in there but I don't know. Too lazy to check it again...requires seting up a laptop with no working battery

[LGT-3-6]

So I guess no one has found this information so far.
I really need to cycle my ABS unit. Older cars can do this by pulling and reinserting the ABS fuse, but not me. Any clues as to which memory location?

[cdvma]

So I guess no one has found this information so far.
I really need to cycle my ABS unit. Older cars can do this by pulling and reinserting the ABS fuse, but not me. Any clues as to which memory location?

Nada. I need to make friends with a dealership tech.

[LGT-3-6]

So I guess no one has found this information so far.
I really need to cycle my ABS unit. Older cars can do this by pulling and reinserting the ABS fuse, but not me. Any clues as to which memory location?

Nada. I need to make friends with a dealership tech.

Don't we all. I actually have a sniffer setup around here, and I wrote a ghetto ECU emulator too.. just missing the SSM