Po455 & P1680 codes

On my 04 Trailblazer it 1st had a code of P0455 which I cleared then the

next day it went to the reduced power mode. I stopped it shut it off then

restarted it. It ran fine on the way home . I checked the code it was the

P1680. It has a the noisey air pump under the drivers seat.

Any ideas where to start?

Welcome to AF Check this link for code definitions.http://service.gm.com/gmspo/mode6/pdf/2002/2002file2.pdf

it looks like an issue with the pcm...try disconnecting the battery for about half an hour and see if that helps...its worth a try

Actually 1680 points to the TPS or wiring to it or the stepper motor, 455 is the vent solenoid or circuitry.

my car just got this 1680 code. GM issued a message saying that you need to reprogram the PCM when you see this and it cost me 113 at the dealer to do this. and it took the day to do. but afterwards my car was running a lot cleaner and shifted much better.

Good info,but look at the dates before posting, this is too old, thanks.