03" suburban with PCM issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

81ShrtBox · 05-06-2011, 07:19 PM

First off... Hi, been on the site but always about my 81" GMC. This time its my daily driver. I have a 2003 suburban I bought new in 2003. It only has 104,000 miles on it. It's well maintained. You could eat off the engine. It has flowmaster split dual exhaust, k&n cold air system and 24" wheels. I had wheels put on it from day one. I only pull a 6x12 enclosed trailer with one stripped down race bike. Bike isn't heavy at all. Tyranny started acting up. It only gets 1st and 3rd and reverse if shifted manually. I have one buddy thats a ASE tech, he ran a few checks and said its a faulty pcm. My neighbor runs a transmissions shop and he also said the same. But neither can tell me if I can use one of another truck without flashing like I would have to with a new one. I have a used pcm on the way. Just want to know if I'm wasting my time. All this stemmed from the green engine cleaner at one of the new self car washes. It corroded my battery post so bad the truck wouldn't start. I ran out of change and didn't wash that crap off.

Input please
Posted via Mobile Device

clinebarger · 05-06-2011, 10:43 PM

A new/used PCM will have to be flashed/reflashed with your VIN.
I highly doubt your PCM is bad, Are there any codes?

81ShrtBox · 05-07-2011, 12:11 PM

Quote:

Originally Posted by clinebarger

A new/used PCM will have to be flashed/reflashed with your VIN.
I highly doubt your PCM is bad, Are there any codes?

my buddy told me it was displaying every code which deals with the PCM and the only reason it would be throwing that many codes is if the PCM was bad. I have one coming for free so all it would cost me is the flashing.

clinebarger · 05-08-2011, 09:27 PM

Quote:

Originally Posted by 81ShrtBox

my buddy told me it was displaying every code which deals with the PCM and the only reason it would be throwing that many codes is if the PCM was bad. I have one coming for free so all it would cost me is the flashing.

I hope the PCM fixes it. I would still like to know what codes were?

81ShrtBox · 05-09-2011, 09:47 PM

Quote:

Originally Posted by clinebarger

I hope the PCM fixes it. I would still like to know what codes were?

I will post the codes when I get to the shop to have the PCM programmed with my vin

81ShrtBox · 06-02-2011, 08:38 PM

found out it was definately the PCM. I had another car on the drive way so i just parked the burban for a while. As soon as my new PCM arrives I'll post the results... in the meantime... Suburban SS project in going full steam ahead

Instead of getting another note i decided to re-do this one

clinebarger · 06-02-2011, 09:44 PM

Quote:

Originally Posted by 81ShrtBox

found out it was definately the PCM. I had another car on the drive way so i just parked the burban for a while. As soon as my new PCM arrives I'll post the results... in the meantime... Suburban SS project in going full steam ahead

Instead of getting another note i decided to re-do this one

How do you KNOW the PCM is bad? The 03-07 Blue/Green PCMs are very reliable, Ive worked on hundreds of these trucks, Ive never had a faulty PCM put the transmission in "limp mode" as the only symptom. Still waiting on those codes

Have you or the "two mechanics" physically checked for 12 volt power to the transmission at "pin E"

81ShrtBox · 06-02-2011, 09:53 PM

Quote:

Originally Posted by clinebarger

How do you KNOW the PCM is bad? The 03-07 Blue/Green PCMs are very reliable, Ive worked on hundreds of these trucks, Ive never had a faulty PCM put the transmission in "limp mode" as the only symptom. Still waiting on those codes

Have you you or the "two mechanics" physically checked for 12 volt power to the transmission at "pin E"

what started the whole deal was a corroded positive side battery terminal... I mean to the point of not letting the truck start. I cleaned the terminal and terminal connection, the truck started but these issues surfaced

i was willing to try the PCM because it was 'free" I will try that. hadnt moved the truck since the last post, just bought my oldest a 2007 Altima so I've been driving it. I will post my findings tommorrow...

thanks....

clinebarger · 06-02-2011, 10:55 PM

Check the fuse labeled "IGN 0" in the I/P (Instrument Panel) fuse block (On the end of the dash on the drivers side)

The fuse circled....

81ShrtBox · 06-03-2011, 01:05 PM

HA..HA..HA.... IT WORKED..... IM SO HAPPY I DONT KNOW WHAT TO DO

It was the fuse... I checked every fuse except that one

THANKS Clinebarger

05-06-2011, 07:19 PM	#1
81ShrtBox MadMan Join Date: Nov 2010 Location: Hammond, La. Posts: 490	03" suburban with PCM issues First off... Hi, been on the site but always about my 81" GMC. This time its my daily driver. I have a 2003 suburban I bought new in 2003. It only has 104,000 miles on it. It's well maintained. You could eat off the engine. It has flowmaster split dual exhaust, k&n cold air system and 24" wheels. I had wheels put on it from day one. I only pull a 6x12 enclosed trailer with one stripped down race bike. Bike isn't heavy at all. Tyranny started acting up. It only gets 1st and 3rd and reverse if shifted manually. I have one buddy thats a ASE tech, he ran a few checks and said its a faulty pcm. My neighbor runs a transmissions shop and he also said the same. But neither can tell me if I can use one of another truck without flashing like I would have to with a new one. I have a used pcm on the way. Just want to know if I'm wasting my time. All this stemmed from the green engine cleaner at one of the new self car washes. It corroded my battery post so bad the truck wouldn't start. I ran out of change and didn't wash that crap off. Input please Posted via Mobile Device __________________ 81" Shortbed C10 Full Restoration underway, who needs a budget?? LS Pro Touring Build Last edited by 81ShrtBox; 05-06-2011 at 09:41 PM.

05-06-2011, 10:43 PM	#2
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: 03" suburban with PCM issues A new/used PCM will have to be flashed/reflashed with your VIN. I highly doubt your PCM is bad, Are there any codes?

06-02-2011, 08:38 PM	#6
81ShrtBox MadMan Join Date: Nov 2010 Location: Hammond, La. Posts: 490	Re: 03" suburban with PCM issues found out it was definately the PCM. I had another car on the drive way so i just parked the burban for a while. As soon as my new PCM arrives I'll post the results... in the meantime... Suburban SS project in going full steam ahead Instead of getting another note i decided to re-do this one __________________ 81" Shortbed C10 Full Restoration underway, who needs a budget?? LS Pro Touring Build

06-02-2011, 10:55 PM	#9
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: 03" suburban with PCM issues Check the fuse labeled "IGN 0" in the I/P (Instrument Panel) fuse block (On the end of the dash on the drivers side) The fuse circled.... Attached Images

06-03-2011, 01:05 PM	#10
81ShrtBox MadMan Join Date: Nov 2010 Location: Hammond, La. Posts: 490	Re: 03" suburban with PCM issues HA..HA..HA.... IT WORKED..... IM SO HAPPY I DONT KNOW WHAT TO DO It was the fuse... I checked every fuse except that one THANKS Clinebarger __________________ 81" Shortbed C10 Full Restoration underway, who needs a budget?? LS Pro Touring Build Last edited by 81ShrtBox; 06-03-2011 at 01:14 PM.



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