Hey All,

I just recently purchase an '03 Silverado 5.3L from a guy off craigslist. When I purchased it--it had 6 error codes that pulled up and I've since corrected 4 of them. Now all Im left with is 2, and thats where I need some help. The last thing that I replaced was the ignition switch and that corrected 3 solenoid codes in the transmission. Im left with the codes P0740 & P0758. From what I read, it is very likely that this is an electrical issue and not a solenoid issue, but Im not entirely sure. Im not down for paying labor to a tranny shop, so does anyone have any ideas? Thanks for the help in advance.

 

how does it drive? have you dropped the pan and filter to check for metal or fluid condition?

haven't looked up the codes im just verifying the basics first

 

Let me give you some more background...The guy who I purchased it from had the transmission rebuilt once, then had it dropped again and the mechanic said there was nothing wrong that he could find with it. That being said, I havent dropped the pan yet, but I have purchased the solenoids that correspond with those error codes. I wont receive one until Tuesday, so I was waiting until then to drop the pan.

 

When I clear the codes (disconnect the battery for more than an hour) it drives like normal, shifting correctly. When the SEL is on, if I'm in drive, the truck only moves accelerates and stays in 3rd. At this point, I can manually shift down to second, then to 3rd, but 1st doesnt work. This is "limp mode" from what I understand.