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View Full Version : ECU swap: OBD2 for OBD1?

davew833
12-18-2008, 02:32 PM
Has anyone thought of doing this? Would it be plug and play, or is the wiring harness/connectors different for OBD2? I'd like to run an ECUtune Stage 1 chip in a '96, but of course it's not made for OBD2. Could I swap my ECU for a pre-96, I wonder?
TomsSVX
12-18-2008, 03:12 PM
change the TCU as well.. It can be done.

Tom
stiguy
12-18-2008, 07:28 PM
what about the other way around?
TomsSVX
12-18-2008, 08:13 PM
what about the other way around?

No, there were additions to the OBDII systems that the OBDI's do not have. BUT everything from an OBDI system is and should be present in an OBDII

Tom
SVX92-97
12-18-2008, 08:31 PM
Do you need to swap the TCU when swapping a OBDII engine and tranny into a OBDI car. My OBDII tranny shifts smooth as butter in my OBDI car. Just thought Id ask
TomsSVX
12-18-2008, 08:37 PM
No because you are using an OBDI ECU... There is communications beyond the OBDI standards between the OBDII ECU and TCU. If you change one, it is suggested you change the other as well.

Tom
LetItSnow
12-18-2008, 09:08 PM
What about inspections? The ECU will probably have to be swapped back to OBD-II right? (My '92 cares not; I'm just in on this one for the tech.)
davew833
12-18-2008, 09:18 PM
TomsSVX replied to me privately and told me the OBDI/OBDII wiring/connectors were different. Can anyone confirm? I trust his expertise, but I'd love him to be wrong in this case.
TomsSVX
12-18-2008, 09:45 PM
The OBDI- harness is comprised of 4 seperate plugs. The OBDII harness is one single plug... There must be a jumper harness made.

Rob, yes you would need to jump back to OBDII ECU's for inspection considering most scan the ECU through the diagnostic ports... Which will not be functioning w/ an OBDI ECU

Tom
b3lha
12-19-2008, 03:30 AM
Does anybody have a good photo of an OBD2 SVX ECU with the lid off.
LetItSnow
12-19-2008, 06:16 AM
...yes you would need to jump back to OBDII ECU's for inspection...
I kinda figured that the diagnostic port wouldn't be there ;) but I wasn't sure if there was a year that inspections instituted connecting to OBD-II, or if it was all OBD-II cars.
TomsSVX
12-19-2008, 06:59 AM
Does anybody have a good photo of an OBD2 SVX ECU with the lid off.

If I have an extra ECU ill open it up

Tom