So I swapped from a 4.3L V6 to a 5.3L V8 on my 2003 Silverado 1500. I have the following codes on:

p0315 - crank relearn
p0178 - fuel composition sensor (my truck isnt e85 but the computer must think it is)
p0480/481 - efans

my battery light is on but im getting 14 volts. I checked all the wiring and I have 1 ohm from the batt to the alt, batt to frame, frame to motor, and motor to batt. I did the big 3 upgrade and also tried a new 105 amp alternator with no success. it left me thinking that the truck was calling for a 145 amp alternator, so i went out and got one. still no success.

any suggestions? for some reason i dont think its tuning related

 

I wish i knew, Since i started modding my truck and altering the tuning, ive had the damn battery display in my message center flash on and off. VERY annoying!!!

 

yeah its certainly odd

 

i had this issue before and for the life of me i couldnt figure it out, so i had an extra ecm so i just wrote my tune to it and solved the battery light issue..


not saying this will solve yours just saying it did solve mine..

 

thanks for the info skeet

 

I have 2 PCMs and both do it. Wander if i can delete it in EFI Live? I'll have to look.

 

Let me know what you find

 

If its a swap, how did you wire the plug that comes off the alternator. I'm dealing with that now trying to make a custom engine harness.

 

i just used a stock v8 harness

 

I just went in my dtc's and turned off generator L terminal, and generator F terminal to no error reported. Solved my problem, no bright blinking red battery anymore.