why cant i pull a code off of PCM???

Reply Subscribe

Thread Tools

Search this Thread

Nov 1, 2008 | 03:58 PM

impaled

Thread Starter

TECH Regular

Joined: Sep 2008

Posts: 443

Likes: 0

From: tampa

why cant i pull a code off of PCM???

i dont have any codes now, but had one before and tried my scanner and it said "MIL ON" but "no codes."

so i went to advance auto and asked them to throw their scanner on it. they said it couldnt make a connection. it was a guy that i didnt know there so i wasnt confident of what he was doing, so i had him get my buddy there who knows what he is doing... my friend said the same thing. it couldnt connect.

then... i had him throw it on his 99 mustang GT and the *same scanner* said it was connected, even though he had no codes.

i dont have any now, but am curious as to why i cant get the reader to connect.

the odd thing is that the car runs perfect and the stock wiring looks untouched. if the PCM wasnt working or something stupid, wouldnt the car be running like crap?

any thoughts???

Nov 1, 2008 | 04:15 PM

2001NBMZ28

TECH Senior Member

Joined: Dec 2001

Posts: 5,399

Likes: 3

From: Jacksonville, FL

Do you have power to the DLC port? If not check the fuse. On a LS1 it's the CIG/ACCY fuse.

Nov 1, 2008 | 04:39 PM

96capricemgr

11 Second Club

iTrader: (1)

Joined: Sep 2004

Posts: 11,975

Likes: 15

Might verify the pcm part number. It is fairly common to swap OBD1 pcms into OBD2 cars.
From memory the OBD1 pcm PN ends in 8501.

Nov 1, 2008 | 05:42 PM

impaled

Thread Starter

TECH Regular

Joined: Sep 2008

Posts: 443

Likes: 0

From: tampa

all fuses are good. i had a chase around wiring problem so all fuses are good.

good thoughts, but why would it be converted to OBD1?
what would be the advantage of that?

Nov 1, 2008 | 05:56 PM

96capricemgr

11 Second Club

iTrader: (1)

Joined: Sep 2004

Posts: 11,975

Likes: 15

Well there was a time when we could not tune OBD2 and even today if you are doing the tuning yourself it is cheaper to tune OBD1 though everything you need to play with OBD2 is available.

Just a few months ago someone else here bought a used car and found this exact thing was a 96 or 97 car with a 94-5pcm in it.

Nov 1, 2008 | 06:49 PM

impaled

Thread Starter

TECH Regular

Joined: Sep 2008

Posts: 443

Likes: 0

From: tampa

can i tell from the pins on the connector? IIRC they had a different amount of leads.

Nov 1, 2008 | 09:05 PM

96capricemgr

11 Second Club

iTrader: (1)

Joined: Sep 2004

Posts: 11,975

Likes: 15

The OBD1 pcm plugs in same as the OBD2 underhood and under dash is untouched. To check this you will need to unbolt the pcm and look at the part number stickers on it.

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Pouria Savadkouei

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Verdad Gallardo

7 Most Reliable High-Performance Engines GM Has Ever Built

Verdad Gallardo

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Verdad Gallardo

6 Common C5 Corvette Failures and What's Involved In Repairing Them

Pouria Savadkouei

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Verdad Gallardo

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Pouria Savadkouei

Top 10 Most Powerful Chevy Trucks Ever Made!

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Verdad Gallardo

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Verdad Gallardo

Nov 6, 2008 | 10:55 AM

impaled

Thread Starter

TECH Regular

Joined: Sep 2008

Posts: 443

Likes: 0

From: tampa

Quote:

Originally Posted by 2001NBMZ28

Do you have power to the DLC port? If not check the fuse. On a LS1 it's the CIG/ACCY fuse.

a code popped on today (i was planning to get into the PCM this weekend), so i put the reader on it and it said that there was no connection.

i pulled the CIG/ACCY fuse and it was blown. replaced fuse, threw the reader back on and pulled off the code.

thanks NMBZ28!