BG9 EJ25 Legacy ECU "25"

[mrdjc]

I am starting this thread off for a fellow member over on the UKLegacy.com forums.
I tried helping him understand his ECU but I am lost now, I hope that Phil can help us understand what's going on.

I am unsure of the year of the vehicle, its a EJ25 BG9 (Legacy Mark 2, Wagon, 2.5)
Rom ID: A20114

The slight confusion I have is.
It's a JECS ECU
It has a DENSO "New" Rom ID.
VWRX Works and finds certain parameters.
Polaris Snowmobile software does not work or resolve the Rom ID.
It has NO OBD plug but does have the SSM plug (Old loom??)

How can it be a JECS ECU but yet have a "new" OBD Rom ID?
From all that I have seen all the Pre OBD ECU's all had a Rom ID starting with "7"
I thought (Probably wrongly) that Subaru went straight over onto DENSO at the end of 1998 to be OBD-II compatible.

Cheers,
Daniel.

[b3lha]

How can it be a JECS ECU but yet have a "new" OBD Rom ID?
From all that I have seen all the Pre OBD ECU's all had a Rom ID starting with "7"
I thought (Probably wrongly) that Subaru went straight over onto DENSO at the end of 1998 to be OBD-II compatible.

Well, we don't know for sure what the "7" in the ROM ID represents. We know that the OBD1 Hitachi and JECS units all seem to start with 7, even the transmission computers. We know that the later Denso units all start with "A". But it's possible that there are also JECS units that also start with "A".

I thought (Probably wrongly) that Subaru went straight over onto DENSO at the end of 1998 to be OBD-II compatible.

There are also some OBD2 cars with JECS units between approx 1996 and 2000. Mostly USDM I think. OBD2 wasn't a legal requirement in Europe until 2001.

I am unsure of the year of the vehicle, its a EJ25 BG9 (Legacy Mark 2, Wagon, 2.5)
Rom ID: A20114
It's a JECS ECU
VWRX Works and finds certain parameters.
Polaris Snowmobile software does not work or resolve the Rom ID.
It has NO OBD plug but does have the SSM plug (Old loom??)

If it has an SSM plug and no OBD2 plug then we should assume for the moment that it is an OBD1 unit.
From looking at the VWRX SelectMonitor.ini file I can see that there are some definitions for ROM IDs beginning with "A". They are European market cars from around 1997-99.

The parameter addresses are all low numbers so it's clearly a different system to everything we've looked at so far. The addresses are 16 bit, so presumably it has a 16 bit address space. Unless, of course, it's a 32 bit CPU that just emulates 16 bit for the sake of the select monitor. I hope that's not the case, but it's strange how VWRX worked but not Polaris. They both use the same protocol.

I suggest the following:

1. Get a photo of the circuit board and identify the type of CPU chip.

2. See if it will talk to my ecudump program and get a dump of memory from 0000 to FFFF. You will need linux for this, download a knoppix cd or use a USB stick with pendrivelinux. I can help you if you haven't used linux before.

[racinggreen]

Gooday all, mine is the BG9 EJ25 Legacy JECS25 ECU.
Took the top off the JECS ECU today.
The board is an A19-001 DC1 2
The main chip is an A12-212-750 it looks like a 32 bit processor
the second chip 808B105

there are several JECS chips including 16252-02 16253 01


This is the rom dump from select monitor and select monitor dump.
Will try your other software asap.
<<<< SelectMonitorDump Started: 23/02/2009 10:44:17 AM >>>>
<<<< SelectMonitor Started: 23/02/2009 10:45:27 AM ROMID: A201 >>>>
#### Address 1305 to 1320 at 23/02/2009 10:44:17 AM ####
1305: 90 11.52 288 3600 094 2.81 36.86 56.25 1406.3 2812.5 016 1152 0.19
1306: 83 10.48 262 3275 081 2.56 33.54 51.17 1279.3 2558.6 003 1048 0.04
1307: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
1308: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
1309: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130A: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130B: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130C: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130D: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130E: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130F: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
1310: 9B 12.40 310 3875 105 3.03 39.68 60.55 1513.7 3027.3 027 1240 0.32
1311: 9B 12.40 310 3875 105 3.03 39.68 60.55 1513.7 3027.3 027 1240 0.32
1312: 92 11.68 292 3650 096 2.85 37.38 57.03 1425.8 2851.6 018 1168 0.21
1313: 00 0.00 000 0000 -050 0.00 0.00 0.00 0.0 0.0 -128 0000 -1.51
1314: 61 7.76 194 2425 047 1.89 24.83 37.89 947.3 1894.5 -031 0776 -0.36
1315: 00 0.00 000 0000 -050 0.00 0.00 0.00 0.0 0.0 -128 0000 -1.51
1316: 31 3.92 098 1225 -001 0.96 12.54 19.14 478.5 957.0 -079 0392 -0.93
1317: 23 2.80 070 0875 -015 0.68 8.96 13.67 341.8 683.6 -093 0280 -1.09
1318: 1E 2.40 060 0750 -020 0.59 7.68 11.72 293.0 585.9 -098 0240 -1.15
1319: 00 0.00 000 0000 -050 0.00 0.00 0.00 0.0 0.0 -128 0000 -1.51
131A: 00 0.00 000 0000 -050 0.00 0.00 0.00 0.0 0.0 -128 0000 -1.51
131B: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
131C: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
131D: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
131E: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
131F: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
1320: 7E 10.08 252 3150 076 2.46 32.26 49.22 1230.5 2460.9 -002 1008 -0.02
#### Address 1305 to 1320 at 23/02/2009 10:44:22 AM ####
1305: 90 11.52 288 3600 094 2.81 36.86 56.25 1406.3 2812.5 016 1152 0.19
1306: 83 10.48 262 3275 081 2.56 33.54 51.17 1279.3 2558.6 003 1048 0.04
1307: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
1308: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
1309: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130A: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130B: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130C: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130D: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130E: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
130F: 80 10.24 256 3200 078 2.50 32.77 50.00 1250.0 2500.0 000 1024 0.00
1310: 9B 12.40 310 3875 105 3.03 39.68 60.55 1513.7 3027.3 027 1240 0.32
1311: 9B 12.40 310 3875 105 3.03 39.68 60.55 1513.7 3027.3 027 1240 0.32
1312: 92 11.68 292 3650 096 2.85 37.38 57.03 1425.8 2851.6 018 1168 0.21
1313: 00 0.00 000 0000 -050 0.00 0.00 0.00 0.0 0.0 -128 0000 -1.51
1314: 61 7.76 194 2425 047 1.89 24.83 37.89 947.3 1894.5 -031 0776 -0.36
1315: 00 0.00 000 0000 -050 0.00 0.00 0.00 0.0 0.0 -128 0000 -1.51
1316: 31 3.92 098 1225 -001 0.96 12.54 19.14 478.5 957.0 -079 0392 -0.93
1317: 23 2.80 070 0875 -015 0.68 8.96 13.67 341.8 683.6 -093 0280 -1.09
1318: 1E 2.40 060 0750 -020 0.59 7.68 11.72 293.0 585.9 -098 0240 -1.15
1319: 17 1.84 046 0575 -027 0.45 5.89 8.98 224.6 449.2 -105 0184 -1.24
131A: 0A 0.80 020 0250 -040 0.20 2.56 3.91 97.7 195.3 -118 0080 -1.39
131B: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
131C: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
131D: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
131E: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
131F: 06 0.48 012 0150 -044 0.12 1.54 2.34 58.6 117.2 -122 0048 -1.44
1320: 7E 10.08 252 3150 076 2.46 32.26 49.22 1230.5 2460.9 -002 1008 -0.02
#### Address 1305 to 1320 at 23/02/2009 10:44:27 AM ####


Photos to follow soon.
Thanks Peter.

[racinggreen]

This should be the ecu photo.
Sorry having file size issues.

[b3lha]

A12-212-750 is a JECS part number. We'll have to do a bit of trial and error to find the actual chip type.

The data you posted is probably part of the RAM because the value at 1319 is different in the two scans.

I think that's all I can tell you at present. So far there is not much to go on.