2006 Hummer H3 Check Engine Light with P0017, P0171, P0300, and P2176 Codes - Diagnosis & Fixes

You will need a scan tool capable of reading live data to properly diagnose the issue. - P0017 indicates a Variable Cam Timing (VCT) problem, which could be caused by a faulty solenoid, low oil pressure, or engine sludge. - P0171 points to a lean air-fuel mixture; check fuel trims, oxygen sensor readings, and ensure proper fuel pressure. - P0300 suggests misfiring across multiple cylinders; verify if you're using AC Delco spark plugs. Clean the injectors according to the manufacturer's TSB (Technical Service Bulletin). - P2176 indicates a mismatch between commanded throttle position and actual throttle sensor readings (TP1 and TP2). These sensors detect throttle position and must agree for proper engine operation. This vehicle has known technical service bulletins that may assist with troubleshooting. Relevant TSBs include: PIP4945B, PIP4573, TSB 06-06-01-017, and #03-06-04-030G.

Thanks for the input. I actually brought the truck to a professional shop today. I don't have access to advanced diagnostic tools, so I'll let them handle the repair and diagnosis.

By the way, what does VCT mean? Is it vacuum-related? And what is a TSB? Also, are TP1 and TP2 referring to throttle position sensors?

TP1 and TP2 refer to Throttle Position Sensors. VCT stands for Variable Cam Timing — a system that adjusts valve timing in the engine for improved performance and efficiency. TSB means Technical Service Bulletin, which are official manufacturer-released repair guides or updates for specific vehicle issues.