95 OBDII ? and scanner.

I'm told various ways to verify OBD2 on my 95 LT, but I want to make sure it will supply data to the scanners.

It has vin code W, with 4.3 engine and the computer thingy is on the pass side inner fender with many connectors. I'm told this is how to tell if it's obdII

Is it really obd2 or is there some other ways to tell for sure? I don't want to get a scanner with the options I want just to find out my vehicle will not give out the info. Is there a way to list all the parameters that can be read on my blazer?

it is obd1. i call them obd1&1\2. most 94 & 95 gm cars and trucks require a reader to retrive codes. some you can jump the data link connector to flash codes.

I'm told various ways to verify OBD2 on my 95 LT, but I want to make sure it will supply data to the scanners.

It has vin code W, with 4.3 engine and the computer thingy is on the pass side inner fender with many connectors. I'm told this is how to tell if it's obdII

Is it really obd2 or is there some other ways to tell for sure? I don't want to get a scanner with the options I want just to find out my vehicle will not give out the info. Is there a way to list all the parameters that can be read on my blazer?


Go here and see if you have obd11 or OBD1
http://www.troublecodes.net/OBD2/
If the 16 pin OBD11 conector you can not jump it for codes.
The fender mounted VCM is OBD11
MT

it is obd1. i call them obd1&1\2. most 94 & 95 gm cars and trucks require a reader to retrive codes. some you can jump the data link connector to flash codes.

Serve the 95 blazer comes both ways.
About as confusing as the 94-95 gm cars.:grinyes: :lol:
The fender mounted VCM on a code w Blazer is a OBD11 set up.
If PCM is behind glove box it is a OBD1
MT

Hey thanks for the BAT link. It has a lot of nice links to scanners that I'll need to decide. I'm more confused now than I was whether or not I have 1 or 2

My VCM (with lots of wires and connections) is definately on the right fender.
My sticker says OBD1 certified
My connector is OBD2 connector
BAT says that it can have the connector, but may be obd1 and to jump pin 5&6 to get codes (like the older ones)

My connector has only pins 2,4,5,9,13,16

I think that mine is a late 95 and even though the sticker says obd1 certified, it is obd2.

Some more evidence is that I have been told by mechanics that have checked it that cyl no.1 has misfired, and I also have been told that a downstream o2 sensor was bad in bank 1. Does this necessarily mean that it is indeed obd2?

You cannot question scanner comments from someone called "MT 2500" I'd think. '94 and '95 were pretty confusing years. I purposely avoid shopping for them, and that is one primary reason.

Maybe I'll ask the right question. I really don't care if it's 1 or 2.

What are the codes, faults, sensors I can read with this vehicle provided I have the correct tool or software?

Maybe I'll ask the right question. I really don't care if it's 1 or 2.

What are the codes, faults, sensors I can read with this vehicle provided I have the correct tool or software?

96 was the first year for OBD11 systems.
But on your Blazer 95 they come both ways but.
With the computer/VCM on the right fender under the coolant tank it is OBD11.
You should be able to read all P codes with scanner or code reader.
Most all OBD11 scanners will give you engine data and codes and P codes.
But a engine transmission capable scanner will have a transmission section that will give you more transmission data than just a OBD11 scanner.
Here is a list of OBD11 codes that a OBD11 scanner will read.
http://www.troublecodes.net/OBD2/
MT

Hey thanks for the BAT link. It has a lot of nice links to scanners that I'll need to decide. I'm more confused now than I was whether or not I have 1 or 2


My VCM (with lots of wires and connections) is definately on the right fender.
My sticker says OBD1 certified
My connector is OBD2 connector
BAT says that it can have the connector, but may be obd1 and to jump pin 5&6 to get codes (like the older ones)

My connector has only pins 2,4,5,9,13,16

I think that mine is a late 95 and even though the sticker says obd1 certified, it is obd2.

Some more evidence is that I have been told by mechanics that have checked it that cyl no.1 has misfired, and I also have been told that a downstream o2 sensor was bad in bank 1. Does this necessarily mean that it is indeed obd2?

Ask the mechanic that tested it what it was?
And post back them code no.
obd1 is 2 digit code
obd11 is 4 digit p codes
What was the code no.?
Also with a misfire alway fix the missfire first before testing 02 sensors.
A missfire can cause a 02 sensor code.
MT

Ask the mechanic that tested it what it was?
And post back them code no.
obd1 is 2 digit code
obd11 is 4 digit p codes
What was the code no.?
Also with a misfire alway fix the missfire first before testing 02 sensors.
A missfire can cause a 02 sensor code.
MT
mt 2500 I've gotta say i disagree I read on the muauls behind glovebox is obd2 and on fender is obd1 there are actilly 3 diffent boxs for 95... so yes its confuseing i do however have the box he speaks of that says obd1 cerf. on my 95 and with the 2 port inside the car and guess what...I contacted genral motors with my vin and they told me it was obd1 so if you want to be sure go to the dealer have em run your vin...thats the easyest way to know..and yes 96 and up were all obd2 .

Thanks for the help, I'll catch on sooner or later. I agree that mine is obd2 and my sticker that's under the hood is a generic sticker that was required for all compatible obd1 systems and merely says that it is "at least" obd1 certified, but doesn't go beyond that. I think that perhaps they went to obd2 engines and related parts yet the chassis was already built with sticker.

Anyways with all those p codes I'll get a good start on diagnosis, have to get a lap-top and have to decide on some hardware and software yet.

The mechanis gave me those codes a few years ago, I don't rmrmber the number, onlt that He said I had a bad bank 1 downstream o2 sensor. I remember being impressed with his knowledge, but never was impressed enough to change it .

Same mechanic who mis diagnosed my heater/ac problem and same guy who misdiagnosed my 4wd problem, lol.

mt 2500 I've gotta say i disagree I read on the muauls behind glovebox is obd2 and on fender is obd1 there are actilly 3 diffent boxs for 95... so yes its confuseing i do however have the box he speaks of that says obd1 cerf. on my 95 and with the 2 port inside the car and guess what...I contacted genral motors with my vin and they told me it was obd1 so if you want to be sure go to the dealer have em run your vin...thats the easyest way to know..and yes 96 and up were all obd2 .

What are your 2 ports in the car?

My connector has only pins 2,4,5,9,13,16

If it was obd1 then it is supposed to have A & B terminals jumped, but I do not even have those pins in the connector.

mt 2500 I've gotta say i disagree I read on the muauls behind glovebox is obd2 and on fender is obd1 there are actilly 3 diffent boxs for 95... so yes its confuseing i do however have the box he speaks of that says obd1 cerf. on my 95 and with the 2 port inside the car and guess what...I contacted genral motors with my vin and they told me it was obd1 so if you want to be sure go to the dealer have em run your vin...thats the easyest way to know..and yes 96 and up were all obd2 .

The certified sticker sometimes gets mixed upp on what one it is.:grinyes:
Well the location of the PCM or VCM and the diagnostic plug is the first clue.
Here is a OBD11 conector.
http://www.troublecodes.net/OBD2/
And here is the OBD1
http://www.troublecodes.net/GM/

One computer behind glove box is a PCM and one on the fender is a VCM.
What is the 3th one?
MT

[QUOTE=MT-2500]The certified sticker sometimes gets mixed upp on what one it is.:grinyes:
Well the location of the PCM or VCM and the diagnostic plug is the first clue.
Here is a OBD11 conector.
http://www.troublecodes.net/OBD2/
And here is the OBD1
http://www.troublecodes.net/GM/

One computer behind glove box is a PCM and one on the fender is a VCM.
What is the 3th one?
MT[/QUOTE
the 3rd being VCM/A

Rental Blazer is correct that there are three different systems. He is, however mistaken on their locations. The first system is located behind the dash and is interfaced using an OBD I assembly line data link connector. This sytem is completely OBD I and codes can be retreived by jumping the pins. The second system is located behind the dash, and is interfaced with an OBD II style Diagnostic Link Connector. This system is OBD I, but requires a special scanner to retreive the codes. The third is located on the passenger side fender, above the coolant reservoir, and uses an OBD II style connector. This system is OBD II, and codes can be retreived with a generic OBD II scanner.

The last one is what I have,



I think, lol. I'm going to auto-zone or dealer to confirm before I purchase my own equipment.

Rental Blazer is correct that there are three different systems. He is, however mistaken on their locations. The first system is located behind the dash and is interfaced using an OBD I assembly line data link connector. This sytem is completely OBD I and codes can be retreived by jumping the pins. The second system is located behind the dash, and is interfaced with an OBD II style Diagnostic Link Connector. This system is OBD I, but requires a special scanner to retreive the codes. The third is located on the passenger side fender, above the coolant reservoir, and uses an OBD II style connector. This system is OBD II, and codes can be retreived with a generic OBD II scanner.

Thanks for the info Blazee.
I have not had the pleasure to run into the one with OBD11 connector with pcm behind.
Or I had the special scanner and did not notice it.
Is it on a 4.3 W or 4.3 Z or both.
MT

[QUOTE=MT-2500]The certified sticker sometimes gets mixed upp on what one it is.:grinyes:
Well the location of the PCM or VCM and the diagnostic plug is the first clue.
Here is a OBD11 conector.
http://www.troublecodes.net/OBD2/
And here is the OBD1
http://www.troublecodes.net/GM/

One computer behind glove box is a PCM and one on the fender is a VCM.
What is the 3th one?
MT[/QUOTE
the 3rd being VCM/A

Thanks for the info rental blazer.
Then the VCM computer on the fender comes two ways?
I will have to heep my eyes open for them.
MT

mt 2500 I've gotta say i disagree I read on the muauls behind glovebox is obd2 and on fender is obd1 there are actilly 3 diffent boxs for 95... so yes its confuseing i do however have the box he speaks of that says obd1 cerf. on my 95 and with the 2 port inside the car and guess what...I contacted genral motors with my vin and they told me it was obd1 so if you want to be sure go to the dealer have em run your vin...thats the easyest way to know..and yes 96 and up were all obd2 .

You are wrong.

Under the glove box is OBDI.

Ontop of the passenger side wheel well is OBDII.

Pure and simple.

Blazee is right, there are three. But lets go back a little further, starting with the ECM, PCM, VCM(A). The ECM is used for Engine Control Only, with the exception of TCC lock up - found under the dashboard. The PCM Powertrain Control Module, primarily used with the W engine from when the 4L60E was used in these trucks (about '92). This system controls, as its name implies Powertrain, ( engine control, transmission shifts, TCC lock-up etc), also found under the dashboard. The VCM(A) Vehicle Control Module, began with limited capabilities, meaning not full fledged OBD II in '95, but defiently certified at least for OBD I. Thats why the sticker says OBD I certified, not enough for OBD II, but well with OBD I requirements. (I also asked why the OBD I certified sticker was used on my '95 Jimmy, and thats the answer I got from the dealer, and hence the OBD 1.5 designation by many people.)

This is where the three different "systems" came into effect in '95

I know that there were two types of the PCM type systems that were used with the OBD I connector, and the OBD II conector. The PCM type system that had the OBD II conector was programmed differently and needed a scanner to read it. The scanner used what was a "manufacturer specific" type of conector. If the OBD I conector was used then the codes could be read by jumping the terminals. Both these systems were under the dashboard. The VCM(A) system was the third system used in '95, and the begining of the real changeover for the full OBD II system to be used, as required, begining in '96. This system could "usually" be scanned using a "generic OBD II"(not sure if all could use the generic conector for the scanner).

Very confusing to say the least, so I understand why some people who have an idea of these systems tend to want to stay away from these years.

Most I have seen are either OBDII with the 16 pin or OBDI with the older connector.

Very VERY few are from the inbetween stages.

I just went to AZ today and the lady told me "no codes" and that it was obd2. I happened to know her also from a tire shop 10 years ago. smallworld.

Well, I'm not real thrilled so far with the software. I did get a scanner and some freeware. It works pretty good, but my vehicle supports very few sensors and I cannot seem to detect any misfires at all. I am wondering how any scanner would be able to tell which cylinder is misfiring and furthermore IF a cylinder was misfiring?

On to my Freeware. I downloaded 9 different ones for trials and freeware, out of the 9 I got 8 to install, 4 to actually connect and 2 to actually read any data and 0 of them to be useful.

The free one I got from scantoll.net is the most basic one and it works the best. A couple of them are pretty impressive if purchased, but I have doubts as to whether or not thy'd do a misfire on my vehicle. another thread perhaps.