Diagnostic Aids

Check for poor connections at PCM. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal connections. Ensure harness is not routed too close to high voltage wires, such as spark plug cables. If connections and harness appear okay, observe TP SENSOR display on scan tool while moving all related harnesses and connectors. A change in scan tool display may indicate a fault location. Turn ignition on, engine off. Using scan tool to observe TP SENSOR display, slowly depress accelerator to wide open throttle. If TP sensor reading is more than 4.88 volts at any time, replace TP sensor. If DTC cannot be duplicated, FAILURE RECORDS data can be used in determining vehicle mileage since DTC was last set. If it is determined that DTC occurs intermittently, performing DTC P1121: TP SENSOR CIRCUIT INTERMITTENT HIGH VOLTAGE  may isolate cause of fault.