Flashing my dang computer!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**michael bustamante** · 04-02-2020, 08:38 PM

So I got my original computer to start one time and now it won't turn on the pump!! Checked everything else and power is not coming out the computer so I got another one..
Now I know there's someone one here that reflashed but I cannot remember for the life of me who that was. Can someone help me. ?
05 Chevy computer dbw

aknovaman · 04-03-2020, 08:44 AM

Power does not come out of a 05 pcm if it's a ls1 style pcm. It grounds the pump relay wire. I can test it for you if needed. Pm me.

I stand corrected. Old man disease hit me again. I can test it for you if needed though.

**MDPotter** · 04-03-2020, 09:56 AM

My 04 Escalade PCM is the other way - the PCM sends a 12V signal to turn on the fuel pump.

**michael bustamante** · 04-04-2020, 03:26 PM

the PCM that went out on me is a 03 suburban with DBW and 5.3 4l602wd.
I can send it to you if you like thatd be great!!
the one I have now is a 05 Silverado 5.3 DBW to replace it if I need to

ls1nova71 · 04-04-2020, 06:51 PM

The PCM sends power to the fuel pump relay, the opposite of fan relays. Have you plugged in the new PCM to see if the pump comes on? It should, so if it doesnt, you have a wiring problem.

aknovaman · 04-04-2020, 06:56 PM

I stand corrected. Old man disease hit me again. Eric is correct. Initially misread my wring diagram. Send them to me anyways, I can read and test the PCM here.

**michael bustamante** · 04-13-2020, 06:47 PM

Quote:

Originally Posted by ls1nova71

The PCM sends power to the fuel pump relay, the opposite of fan relays. Have you plugged in the new PCM to see if the pump comes on? It should, so if it doesnt, you have a wiring problem.

good idea. ill do that first thing in the morning

rodstored-72 · 04-15-2020, 01:51 AM

if you still think you might need a "reflash" I just got done with having mine done a few months ago. I had it done by Brendan at lt1swap. he is very knowledgeable and very reasonably priced.. check him out at lt1swap.com
hope this helps... good luck

**michael bustamante** · 04-18-2020, 12:38 PM

Yup I talked to him online and he suggested I hook up the unflashed computer as well. Same issue so that told me it was the harness. Went over the whole damn thing and I found a ground I had missed hidden right by the fuel inlets in the engine!. Thanks for your help fellas!

04-02-2020, 08:38 PM	#1
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,832	Flashing my dang computer!! So I got my original computer to start one time and now it won't turn on the pump!! Checked everything else and power is not coming out the computer so I got another one.. Now I know there's someone one here that reflashed but I cannot remember for the life of me who that was. Can someone help me. ? 05 Chevy computer dbw __________________ 1967custom

04-03-2020, 08:44 AM	#2
aknovaman Registered User Join Date: Aug 2013 Location: Tecumseh Posts: 355	Re: Flashing my dang computer!! Power does not come out of a 05 pcm if it's a ls1 style pcm. It grounds the pump relay wire. I can test it for you if needed. Pm me. I stand corrected. Old man disease hit me again. I can test it for you if needed though. __________________ Current project 1959 Willys = GEZR TRUK Geezer is a Latin compound word made up of two roots. Gee meaning Urine Stain and Zer meaning your pants are open! FMCDH GBU and GBA http://www.youtube.com/user/aknovaman/videos Last edited by aknovaman; 04-04-2020 at 06:55 PM.

04-03-2020, 09:56 AM	#3
MDPotter Senior Member Join Date: Aug 2018 Location: Western Colorado Posts: 1,165	Re: Flashing my dang computer!! My 04 Escalade PCM is the other way - the PCM sends a 12V signal to turn on the fuel pump. __________________ 1964 Chevy C10 - Gen IV 5.3 Restomod http://67-72chevytrucks.com/vboard/s...d.php?t=768632 1968 GMC C15 - Gen III 6.0 Restomod http://67-72chevytrucks.com/vboard/s...d.php?t=772047 1969 Chevy C10 - Restoration http://67-72chevytrucks.com/vboard/s...d.php?t=809184 1978 Chevy Scottsdale K20 1993 Chevy C1500 - 5.3/T56 swapped 2008 Silverado Duramax

04-04-2020, 03:26 PM	#4
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,832	Re: Flashing my dang computer!! the PCM that went out on me is a 03 suburban with DBW and 5.3 4l602wd. I can send it to you if you like thatd be great!! the one I have now is a 05 Silverado 5.3 DBW to replace it if I need to __________________ 1967custom

04-04-2020, 06:51 PM	#5
ls1nova71 Registered User Join Date: Dec 2009 Location: Independence Mo Posts: 4,118	Re: Flashing my dang computer!! The PCM sends power to the fuel pump relay, the opposite of fan relays. Have you plugged in the new PCM to see if the pump comes on? It should, so if it doesnt, you have a wiring problem. __________________ My '72 short bed build. http://www.ls1tech.com/forums/conver...6-0-4l80e.html 5.3 swap into my RUSTY '71 C10 http://ls1tech.com/forums/conversion...71-c-10-a.html

04-04-2020, 06:56 PM	#6
aknovaman Registered User Join Date: Aug 2013 Location: Tecumseh Posts: 355	Re: Flashing my dang computer!! I stand corrected. Old man disease hit me again. Eric is correct. Initially misread my wring diagram. Send them to me anyways, I can read and test the PCM here. __________________ Current project 1959 Willys = GEZR TRUK Geezer is a Latin compound word made up of two roots. Gee meaning Urine Stain and Zer meaning your pants are open! FMCDH GBU and GBA http://www.youtube.com/user/aknovaman/videos

04-15-2020, 01:51 AM	#8
rodstored-72 chevy truck fan Join Date: Mar 2005 Location: Gilbert, arizona 85298 Posts: 1,970	Re: Flashing my dang computer!! if you still think you might need a "reflash" I just got done with having mine done a few months ago. I had it done by Brendan at lt1swap. he is very knowledgeable and very reasonably priced.. check him out at lt1swap.com hope this helps... good luck

04-18-2020, 12:38 PM	#9
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,832	Re: Flashing my dang computer!! Yup I talked to him online and he suggested I hook up the unflashed computer as well. Same issue so that told me it was the harness. Went over the whole damn thing and I found a ground I had missed hidden right by the fuel inlets in the engine!. Thanks for your help fellas! __________________ 1967custom



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