OBD-II on these trucks

[Bowed]

When did they start using OBD-II on these trucks ? I always thought it was 1996 but someone told me "some " of the trucks had it a couple of years earlier . Thanks.

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[wannabelow]

i have heard that they started doing the 0bd2 in 95 witch was the switch over year and some are obd 2 and some obd but in 96 they were all obd2

[aggiedave98]

I believe it was the law that all '96 and newer cars/trucks in the US had to use obd2. I'm had not heard that there were '95's with it.

[ChevyTech]

Originally Posted by aggiedave98

I believe it was the law that all '96 and newer cars/trucks in the US had to use obd2. I'm had not heard that there were '95's with it.

All cars and light trucks built and sold in the United States after January 1, 1996 were required to be OBD II equipped. In general, this means all 1996 model year cars and light trucks are compliant, even if built in late 1995.

[Tink]

I believe 95s and some late 94s are OBD 1.5...

[ChevyTech]

Originally Posted by Tink

I believe 95s and some late 94s are OBD 1.5...

I know some pre 1996 cars had the OBD1.5, and it is not easy to find information needed for working on them.

[Bowed]

Originally Posted by ChevyTech

I know some pre 1996 cars had the OBD1.5, and it is not easy to find information needed for working on them.

I have a 91 heavy 3/4 ton with a rare at the time 4L80 E ( build code's are MT1/MXO which are factory correct for 4L80E ) . What would this truck be , OBD1 or 1.5 ? Is the control for this early "E" transmission the computer or a stand alone module . I'm having trouble finding info on this set up . Thanks .


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[ChevyTech]

1991 would be an OBD1 system.


MXO - MERCHANDISED, TRANS, AUTO PROVISIONS, O/D

MT1 - TRANSMISSION, AUTO, 4 SPD, THM R2


The RPO codes mean it has a 4 speed automatic transmission with overdrive.
I really doubt it has an electronically shifted 4L80E.

[Bowed]

Originally Posted by ChevyTech

1991 would be an OBD1 system.


MXO - MERCHANDISED, TRANS, AUTO PROVISIONS, O/D

MT1 - TRANSMISSION, AUTO, 4 SPD, THM R2


The RPO codes mean it has a 4 speed automatic transmission with overdrive.
I really doubt it has an electronically shifted 4L80E.

Thanks for the reply . I was using " RPO codes.com " and they were saying MT1 is 4L80E . Anyways it has no throttle valve cable with only wires and connectors . Here is what I have . Thanks