Diagnoistic connector

[longassname]

Does anyone know if all svx's have the same diagnostic connector and if it is ODB I or ODB II? I have a scanner and want to start recording info from my car to make a custom eprom for it.

I believe the 96 and 97 SVX's have OBD II connectors. The rest do not... they were OBD I / Subaru proprietary.

Though... I've seen posts of some 95's having OBD II, I'm not sure if they were actually correct or not..

-Colin

[longassname]

Originally posted by sith
I believe the 96 and 97 SVX's have OBD II connectors. The rest do not... they were OBD I / Subaru proprietary.

Though... I've seen posts of some 95's having OBD II, I'm not sure if they were actually correct or not..

-Colin

That's what i was afraid of since the company my scanner comes from lists OBD II as being for any car 96 or newer. Anyone have a wiring diagram of the pinouts on the 92-95 connectors. I'll just make some jumpers to go from a ford or chevy odb1 scanner harness.

[longassname]

Originally posted by sith
I believe the 96 and 97 SVX's have OBD II connectors. The rest do not... they were OBD I / Subaru proprietary.

Though... I've seen posts of some 95's having OBD II, I'm not sure if they were actually correct or not..

-Colin

Oh, and don't want to forget.........thanks for the obscure knowledge Colin

[Beav]

Originally posted by longassname


That's what i was afraid of since the company my scanner comes from lists OBD II as being for any car 96 or newer. Anyone have a wiring diagram of the pinouts on the 92-95 connectors. I'll just make some jumpers to go from a ford or chevy odb1 scanner harness.

1) OBD-II began showing up on domestics in '94. The Fed required it to be on all '96 and up vehicles in the USA.

2) Typically there are four different protocols for automotive computer communications, just for OBD-II. When considering proprietary systems, (OBD-I if you want to hang a generic name on it) who knows?

3) OBD-II requirements include that one common connector be utilized. It also requires that eighteen (give or take a few, but who's counting?) parameters be accesible through this generic connector. However each OEM can do anything they want after the minimums are met. OBD-II designs allow for up to 1,999 different code definitions, any of which can be used or tossed as each OEM sees fit, depending on their system and engineering. To access the 'enhanced' information (the definitions and/or values beyond the required eighteen) requires a buss adaptor for the scanner to communicate properly. I can only think of one scanner that can auto-detect and adapt without using buss adaptors. It's price begins around $1800- $2000.

4) OBD-I info comms across on one wire, typically. Each system can use an individual protocol of voltage variations to convey information. Highly doubtful that merely "make some jumpers to go from a ford or chevy odb1 scanner harness" would work. If it did the scanner manufacturers wouldn't have been able to sell dozens of different adaptors over the years. Believe it or not there's a lot of savvy techs out there that would have figured that one out if it were possible, especially when each adaptor was about $40-$100 each. Add in that import software for the scanner was additional to the average tune of $500+. Oh, also aftermarket scanners did not provide the full functionality of the OEM devices.

5) The scanner only reports what the computer 'sees'. That doesn't take into account what can change due to poor connections/wiring or a bad computer. A bad ground could really screw you up. Also imagine what a setback a tankful of bad gas could create when trying to decipher/reverse-engineer and re-write a program.

6) Only a few scanners give you limited bi-directional ability, and that'll cost extra. The $80-$300 code readers don't have that ability. That in itself doesn't allow for reading or re-writing to the EEPROM. The only item I can think of at the moment that can be modified in the field through a scanner is some Chrysler products allow for changing the target idle speed. Some scanners have the ability to to flash the EEPROM (on more recent model years) with OEM data, written for specific models and addressing post-production snafus that pop up. You don't just get that ability to flash handed to you either - you have to train and pay for it. Plus not all OEMs have flashable-by-scanner/whatever programs.

7) That should be way more than enough without going into coding, etc..

[longassname]

Originally posted by Beav


1) OBD-II began showing up on domestics in '94. The Fed required it to be on all '96 and up vehicles in the USA.

2) Typically there are four different protocols for automotive computer communications, just for OBD-II. When considering proprietary systems, (OBD-I if you want to hang a generic name on it) who knows?

3) OBD-II requirements include that one common connector be utilized. It also requires that eighteen (give or take a few, but who's counting?) parameters be accesible through this generic connector. However each OEM can do anything they want after the minimums are met. OBD-II designs allow for up to 1,999 different code definitions, any of which can be used or tossed as each OEM sees fit, depending on their system and engineering. To access the 'enhanced' information (the definitions and/or values beyond the required eighteen) requires a buss adaptor for the scanner to communicate properly. I can only think of one scanner that can auto-detect and adapt without using buss adaptors. It's price begins around $1800- $2000.

4) OBD-I info comms across on one wire, typically. Each system can use an individual protocol of voltage variations to convey information. Highly doubtful that merely "make some jumpers to go from a ford or chevy odb1 scanner harness" would work. If it did the scanner manufacturers wouldn't have been able to sell dozens of different adaptors over the years. Believe it or not there's a lot of savvy techs out there that would have figured that one out if it were possible, especially when each adaptor was about $40-$100 each. Add in that import software for the scanner was additional to the average tune of $500+. Oh, also aftermarket scanners did not provide the full functionality of the OEM devices.

5) The scanner only reports what the computer 'sees'. That doesn't take into account what can change due to poor connections/wiring or a bad computer. A bad ground could really screw you up. Also imagine what a setback a tankful of bad gas could create when trying to decipher/reverse-engineer and re-write a program.

6) Only a few scanners give you limited bi-directional ability, and that'll cost extra. The $80-$300 code readers don't have that ability. That in itself doesn't allow for reading or re-writing to the EEPROM. The only item I can think of at the moment that can be modified in the field through a scanner is some Chrysler products allow for changing the target idle speed. Some scanners have the ability to to flash the EEPROM (on more recent model years) with OEM data, written for specific models and addressing post-production snafus that pop up. You don't just get that ability to flash handed to you either - you have to train and pay for it. Plus not all OEMs have flashable-by-scanner/whatever programs.

7) That should be way more than enough without going into coding, etc..

Thanks for the info. I'm hoping it's not quite that bleak. I haven't done any obd I stuff before but I have done obd II. I have a scanner that performs the functions of modes 1-7 of the J1979 OBD-II scan tool specification. The functions include read and display live sensor information while driving - Freeze Frame of data surrounding a trouble code event - pull Trouble Codes in plain English - clear Trouble Codes and reset Check Engine Light - access Oxygen Sensor Tests- display Monitoring Tests - show Pending Trouble Codes and an On-demand Capture mode, which records sensor values up to 29 seconds. I use the capture of sensor values to see where there is room for improvement. The eprom is a whole different story. I was refering to making a performance chip to change a whole host of settings (most chips mainly change the timing curve and fuel) to address any areas that show room for improvement. This involves making an adapter card that accepts an eprom (with the performance settings) to replace some of the factory settings. I have the ability to make the adapter card, an eprom eraser, and an eprom programmer.

I've seen that there are performance chips on the market for the svx, so someone else has done it before successfully. Maybe they got their scans off of a 96 or 97 but if the chips work for any year then the voltages etc for the sensor readings that the computer sees must be the same, right? That's what I'm thinking anyway. If you know differently I would truly appreciate the input. I'd also be interested if you know of a company that has the adapter cable and software for pre obd II svx's. No need to reinvent the wheel. I'm just starting my research on this but i assure you I am an experienced (and educated) enough programmer to pull this off--so you don't have to worry you are or I are wasting our time.

[longassname]

I've determined my 94 definitely doesn't have an obd II connector. It has a 10 pin connector rather than the obd II's 16 pin connector. I noticed it has 9 wires and that on the odb II website there are 9 wires specified on the 16 pin odb II connectore:

Pin 2 - J1850 Bus+
Pin 4 - Chassis Ground
Pin 5 - Signal Ground
Pin 6 - CAN High (J-2284)
Pin 7 - ISO 9141-2 K Line
Pin 10 - J1850 Bus
Pin 14 - CAN Low (J-2284)
Pin 15 - ISO 9141-2 L Line
Pin 16 - Battery Power

Anyone have the pin outs of the 92-95 svx connector?

I've also learned that there are 3 obd II protocols and that almost all asian cars use ISO 9141.

California tested the automatic transmission legacy in 95 and it was fully obd II compliant. Who knows where the svx falls. If the wires on mine are the same as on the odb II cars but the computer doesn't use iso 9141 or have all the info the later ones do i might just buy a 97 computer and slap an obd II diag plug on my harness.

[Beav]

I didn't mean to hack away at anyone's abilities, it's just that there have been so many before you that have bought a cheap code reader and have delusions of grandeur about what can be accomplished with it.

If you want someone to converse with that has extensive Subaru ECU experience I'd recommend contacting these guys:

http://www.ecutek.com

Good luck!

[longassname]

Originally posted by Beav
I didn't mean to hack away at anyone's abilities, it's just that there have been so many before you that have bought a cheap code reader and have delusions of grandeur about what can be accomplished with it.

If you want someone to converse with that has extensive Subaru ECU experience I'd recommend contacting these guys:

http://www.ecutek.com

Good luck!

Thanks for the link I'll look them up.

Mike

Can't you just short 2 of the wires (connect together) and count the flashes ? That's how I read my late model GM's car ?

Just need a guide of what the flashes mean ? ANyone got that ?

Where is the OBD on the SVX anyway ?

[SVXer95]

I believe he was trying to monitor much more than just ce codes. A select monitor does that.

I believe he has it all figured out by now considering all the ECUtune products.

[drivemusicnow]

heh.. pretty interesting thread...

wow... See beav.. .it CAN be done and you helped

[drivemusicnow]

Originally posted by RobSVX
Can't you just short 2 of the wires (connect together) and count the flashes ? That's how I read my late model GM's car ?

Just need a guide of what the flashes mean ? ANyone got that ?

Where is the OBD on the SVX anyway ?

and check in the "how to" folder.. theres a file i believe linking to a couple threads.. the connector is in the driver side foot well, left of the foot rest, behind that panal. you take that off, put a blue wire in pin 1 (i think) of a black connector and read the flashes

[drivemusicnow]

http://www.subaru-svx.net/forum/show...yourself+codes