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View Full Version : Wiring differance between OBDI & OBDII

Ren92
11-06-2006, 01:44 AM
Hey guys I cant get anyone at my dealership that really can tell me any about the difference in the two.I have a LT1 out of a 93' Z28 that I am putting in a 99' Astro van.The Astro is OBDII and the 93' is OBDI. I have the wiring harness from the Z but don't want to run two computers.Are the sensors and plugs the same from 97'-up Z28? Any help would be great.
sbs
11-09-2006, 02:01 AM
Hey guys I cant get anyone at my dealership that really can tell me any about the difference in the two.I have a LT1 out of a 93' Z28 that I am putting in a 99' Astro van.The Astro is OBDII and the 93' is OBDI. I have the wiring harness from the Z but don't want to run two computers.Are the sensors and plugs the same from 97'-up Z28? Any help would be great.

It's hard to tell what you are asking. What does the OBDII-ness of the Astro have to do with anything? You aren't thinking you can run the LT1 with the Astro computer are you?

The difference between a 94-95 LT1 OBD1 computer and 96-97 LT1 OBD2 computer is minimal. When changing between them you just have to change the knock sensors.
Ren92
11-10-2006, 12:36 AM
Yes that is what I am wanting to do. I know I have to flash the computer for the LT1. No one at the dealership could tell me the difference in the 94-95 from 96-97 LT1.So if I get a harness from 96-97 LT1 and change out the knock sensors that should make messing the two harnesses together then I would think.
VinceTrifecta
11-14-2006, 06:51 PM
Basically, the only difference between 94-95 and 96-97 is that 96-97 had a few extra wires connected to the PCM. The following are the added wires:

RED Connector:
Pin 1 - Crankshaft position sensor (yellow wire)

BLACK Connector:
Pin23 - Evap vaccum signal switch (purple wire)

GRAY/CLEAR Connector:

Pin 3 - Bank 2, #2 O2 sensor (right, rear) LOW (tan wire)
Pin 4 - Bank 2, #2 O2 sensor (right, rear) HIGH (purple wire)
Pin 17 - Bank 1, #2 O2 sensor (left, rear) LOW (tan/white wire)
Pin 18 - Bank 1, #2 O2 sensor (left, rear) HIGH (purple/white wire)

BLUE Connector:

Pin 7 - Serial data (Class 2) (purple wire)