Reduced Engine Speed

[annebrehm]

Hi, I have a 2003 Chevy Trailblazer 2 WD, 6 Cyl,and I have codes P1515 and P1516, which comes up as Ignition switch and TB Sensor, I seem to have good excelleration but tends to not want to start sometimes, and when that happens my message center pops up Reduce Engine Power. Now I spoke to a mechanic and he says it's more than likely the TBS not Ignition switch, he wants me to let him run a diagnostic test to see what shows up on his computer... I'm not sure what to do. Any help would be appreciated!!!

[Doug_Scott]

Are you misspelling TPS? Your description sounds just like the bulletin posted here somewhere in regards to defective TPS. Since you cannot just change the TPS, GM is replacing entire throttle bodies. Search for TPS bulletin in the forums.

[gmtech4]

let your tech follow the diagnostic trouble tree,,,,,your fly by wire throttle body has an electrical problem and defaults to a certain throttle amount and lets you know it with the message ,,,have him run the code in his service info for any bulletins (he better do it anyways),,not your job to find it