Diagnostic Aids
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The scan tool displays the TP in volts. The scan tool should display about 0.45-0.85 volts with the throttle closed and the ignition ON or at idle. The voltage should increase at a steady rate as the throttle is moved toward Wide Open Throttle (WOT).
The scan tool will read the throttle angle percentage. 0 percent equals closed throttle. 100 percent equals WOT.
Inspect the condition of the connector and the sensor terminals for moisture or corrosion, and clean or replace the terminals as necessary. If corrosion is found, inspect the condition of the connector seal and repair or replace the seal as necessary. If DTC P0121 is intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.