2004 yukon security light staying on

[irarb01]

hey everyone so this is my first post so please if i’m in the wrong spot tell me. but i’m in need some of help i have a 2004 yukon sle loaded with the 5.3 unfortunately i had to swap the engine today. and since swapping it my security like is staying on and i have no fuel gauge and my fuel pump not coming on and my trans range selector is not there as well. and it won’t do anything no click nothing. any help would be greatly appreciated thanks very much

 

[TJ Baker]

hey everyone so this is my first post so please if i’m in the wrong spot tell me. but i’m in need some of help i have a 2004 yukon sle loaded with the 5.3 unfortunately i had to swap the engine today. and since swapping it my security like is staying on and i have no fuel gauge and my fuel pump not coming on and my trans range selector is not there as well. and it won’t do anything no click nothing. any help would be greatly appreciated thanks very much

Did you use your existing PCM or the PCM from the donor engine?

 

[TJ Baker]

have no fuel gauge and my fuel pump not coming on and my trans range selector is not there as well

This right here sounds to me like there is no class 2 serial data from the PCM.

 

[irarb01]

i used my existing ecm. i also tried running my scan tool and it would not read the vin either

 

[TJ Baker]

i used my existing ecm. i also tried running my scan tool and it would not read the vin either

Are you able to read anything at all from the ECM/PCM with your scan tool?

 

[TJ Baker]

Verify your grounds? Especially G103 which is the main ground for the PCM.

G103 — 2004 GMC Yukon/Denali 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2004 GMC Yukon/Denali 4WD V8-5.3L VIN T.

charm.li

G103 — 2004 GMC Yukon/Denali 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2004 GMC Yukon/Denali 4WD V8-5.3L VIN T.

charm.li

 

[irarb01]

so i found the ground that goes to the back of the motor up top was moved to a bolt for the coil pack. also is that the ground strap going to the front lower side of the engine. my truck is a vin letter Z i haven’t tried putting my scanner back on it yet but i will today after work

 

[irarb01]

thank you for your help i found the main ground for the engine wasn’t tight enough which was causing my issue. tightened it up and working good now i just need a new transmission dipstick cuz the guy who helped me do the swap lost my dipstick somehow. and i got to get new clips for the transmission lines here they go into the radiator