I have a 2003 Saturn Vue Automatic. P0700, P0638, P0121, P2101,P2119, P2176. ETCS problems. A mechanic said you probably don't have to replace throttle body, just clean it and check the wiring.

SOURCE: 03 saturn L300, reduced power engine light came on

You are not the only one. Ive met a good many of Saturn owners (most were 2001 L300 drivers) but they were plagued with the problem you have and practically identical codes. The following remedies have been known to work:

1. Replacement Battery Cable
2.Replacement ECU Wiring Harness
3. Replacement of ECU

SOURCE: need a 03 3.0 v6 awd throttle body, linkage, sensor

Buy it new from many places Search Saturn Parts call local Dealer .
Happy Easter

SOURCE: Code P0121 on 2006 GMC

Classic signs of idle air control not able to cope with sudden engine loads. Cleaning should resolve this. Remove ducting from air cleaner to throttle entrance. Spray with carb. choke cleaner or WD40 spray and wipe back to the alloy finish. clean the the throttle plate and push the throttle open with your fingers and clean in behind as best you can. Clean the passageways to the idle air control valve. Remove the valve and give it a thorough clean up. Reassemble and it should all be good.

SOURCE: Code P0121 on 2006 GMC Envoy Denali Check eng.

Cleaning the throttle body is certainly the right thing to try first. Make sure you clean the throttle plate as well.

Testimonial: "Thanks. It seems to have worked."

SOURCE: I recently did a scan

The letter p stands for powertrain, codes are as follows:
1516-Throttle Actuator Control Module
2101-TAC Position Performance
2119-Throttle Closed Position Performance
2176-Minimum Throttle Position Not learned
All the codes pertain to the Throttle Actuator Contol Module. If you are having driveability issues, you may want to look into replacing the TAC.