just as the topic says a 91 is the OBD 1 right I know there is an OBD2 but cant remember when or they changed help clear this up for me Thanks

 

yes - 96 and up is obd 2

 

i thought the pre 94 was considered ALDL systems.
the 94-95 was obdI and 96-up is odbII.
i maybe mistaken...
airdeano

 

OBDI describes all early versions of "On Board Diagnostics" Including the earliest CCC, TBI, etc.... ALDL is the term given to the diagnostic connector used to access the On Board Diagnostics.

1994 and 1995 were called "Partial Funcion" OBDII vehicles, and were only on certain vehicles. 1994 is was the Buick "L" engine, and the Corvette "P" engine. 1995, the Chevy Blazer w/ the "W" engine was added to the Partial function list. All others were still OBDI. Then in 1996, it was a full phase out of OBDI and ALL vehciles were OBDII.

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'87 Trans Am
S/D TPI retrofit including functional PassKey,
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Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
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Best 1/8: 9.519@72.74

'97 Bonneville SSE

[This message has been edited by GMTech (edited July 29, 2001).]

 

An important difference between the two systems from a prom burning perspective is that there is generally a "hac", tdf or some editor available to alter the programming.

To my knowledge, there is not on OBD II (yet). The programming is another quantum leap from what we have in OBD I that OBD II is going to take a while.

IMO, the best ODB I ECM/PCM is the 8051 used on the later SFI LT1. Lots of drivers, utilizes MAF and MAP, electronic control of the transmission and I believe you can adjust the Speedo within the ECM if you change gears. Best of all, while it is still not completely hac'd like the 7730 (SD TPI), there is a lot information already available on that PCM.

 

OBD II hack, pcm program "LT1-Edit"
-->http://members.tripod.com/CarProgrammer/frmain.htm

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Hybrid Black 5.7L 5 Speed
'95 Competition Yellow Corvette Coupe ZF6

 

OBD II hack, pcm program "LT1-Edit"
-->http://members.tripod.com/CarProgrammer/frmain.htm

------------------
Hybrid Black 5.7L 5 Speed
'95 Competition Yellow Corvette Coupe ZF6

 

blak92!, remember, the LT1 between '93-'95 was still OBDI. Will that program work for '96+??

------------------
FREE CARFAX Record Check

If you live in Southeastern US, check us out!
South East Thirdgen

GM Master Tech
ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
TB Coolant Bypass, Custom Cold Air,
SSM SFC, KYB Shocks, Boxed LCAs, Wonder Bar,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
3.73 Posi
4wheel Disc Brakes
Summit 1-5/8" headers, 2.5" Dynomax catback.

Best 1/8: 9.519@72.74

'97 Bonneville SSE