Truck wont start

Question

I replaced duramax6.6 in my 2003 GMC with 6.6 out of 2003 Chevy 6.6 duramax keep getting p0462 And p1621 truck well not start.what do I do to fix it

Answer 1

P0462 is the fuel level sensor , P1621 is the ECM not programmed, the battery has to be well charged up. use a booster if you have to, P0462 is the fuel system primed? there a bleeder that you have to open to prime the fuel if that not done that has to be performed

​You open the bleeder screw

​ Here you pump . have the fuel flow out then re secured the bleeder.

Also clear the code if anything you have a U0100 set there, when you start the engine you need to crank it more than 30 seconds.If you have a scan tool with data look at the RPM it need to reach above 250 RPM before it starts

Read more : https://www.autocodes.com/p0462.html

Read more : https://www.engine-codes.com/p1621_chevrolet.html