1995 data loging or ecu swap?

[Tektic]

Is there any software I can use to watch the o2 trim and other engine perimeters with my vag-com cable? I tried FreesSSM but it did not work with either of the 2 laptops i tried it on, and couldn't find anyone confirm it to work with a car older than 1999.

If no such software exists is it possible for me to put a newer ecu in and use that to connect to the software?

[Suba_Steve]

I have not ever heard any software that will function with our ecu's. Depending on what car you have a newer ecu more than likly would not work anyway. Even if it did work you would still have issues with available software. You can install aftermarket piggybacks to data log and adjust tunes. Options like the perfect power 6 and the Greddy Emanage series are the most common on these vehicles, they will have to be wired into your harness though.

[Tektic]

So the pinout is different between a 95 and 99?

Do regular obd2 scan tools work properly with this car? I don't uderstsnd why there software counterparts just don't connect.

[rkrenicki]

Subaru's implementation of ODB-II was very basic prior to 2000.

Second gen Legacies (1995-1999) only supports ISO9141-2 K-line communications, and its instruction set is fairly limited. It also is missing the ECU programming pins on 9 and/or 11. Even tuning in third gen (2000-2004) is fairly limited due to the 16-bit nature of the ECUs.

If you really want to tune a factory ECU.. you need to look at 2005+, where Subaru implemented CANBUS and 32-bit ECUs. If you are dead-set on tuning a 1995, then you will either need to run a piggyback or standalone aftermarket ECU.

[Tektic]

I just want to use it to read sensor values with my laptop like I would other cars. I'm trying to dignose an idle surge issue.

[rkrenicki]

The VAG-COM cable does support 9141-2 K-line communication, but I cannot say why your computer will not connect to it. If your computer is trying to query a non-supported PID.. it may be hanging up the ECU. I know I had that issue with my Scangauge II on my 1996. There is a "Supported PIDs Only" mode on the Scangauge to get around that problem.

The following OBD-II PIDs are available on the 1995:

Mode $01 (Powertrain)
01 Number of emission-related powertrain trouble codes and MIL status
03 Fuel system control status
04 Calculated engine load value
05 Engine coolant temperature
06 Short term fuel trim
07 Long term fuel trim
0B Intake manifold absolute pressure
0C Engine revolution
0D Vehicle speed
0E Ignition timing advance
10 Air flow rate from mass air flow sensor
11 Throttle valve opening angle
13 Check whether oxygen sensor is installed.
14 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor—bank 1
15 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor—bank 2
1C On-board diagnosis system

Mode $02 (Powertrain Freeze-frame)
02 Trouble code that caused CARB required freeze frame data storage
03 Fuel system control status
04 Calculated engine load value
05 Engine coolant temperature
06 Short term fuel trim
07 Long term fuel trim
0B Intake manifold absolute pressure
0C Engine revolution
0D Vehicle speed

Mode $03 (DTCs)
Mode $04 (Clear/Reset)

Mode $05 (Oxygen Sensor Monitoring)
01 Rich to lean sensor threshold voltage (constant)
02 Lean to rich sensor threshold voltage (constant)
03 Low sensor voltage for switch time calculation (constant)
04 High sensor voltage for switch time calculation (constant)
05 Rich to lean sensor switch time (calculated)
06 Lean to rich sensor switch time (calculated)
07 Minimum sensor voltage for test cycle (calculated)
08 Maximum sensor voltage for test cycle (calculated)

[Tektic]

So what software was I to use that is known compatable?

Also I read somewhere the pair of unconnectedgreen or black plugs under the dash mat need to be cconnected to read the obd2 port. Is this the case? Does anyone know more about this?