Diagnostic Aids
WARNING: This page is about a different car, the 2001 GMC Savana, 2001 Chevrolet RV Cutaway, 2001 Chevrolet Cutaway, and 2001 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
Scan tool displays throttle position in volts. Scan tool should display about 0.45-0.85 volt with throttle closed and ignition on or at idle. Voltage should increase at a steady rate as throttle is moved toward Wide Open Throttle (WOT). Scan tool will read throttle angle percentage. Zero percent equals closed throttle and 100 percent equals WOT.
If DTC is determined to be intermittent, or TP sensor system is still suspect, see DTC P1121: TP SENSOR CIRCUIT - INTERMITTENT HIGH VOLTAGE .