Diagnostic Aids

Check for a skewed or stuck TP sensor. A faulty TP sensor or sensor circuit can cause PCM to incorrectly calculate the predicted mass air flow value. If scan tool indicates throttle angle reading of 0-13 percent with throttle closed, check for the following conditions and repair as necessary.

• Throttle plate sticking or excessive deposits on throttle plate or throttle bore.
• TP sensor signal circuit shorted to voltage.
• A poor connection or high resistance in TP sensor ground circuit.
• Wiring harness misrouted near spark plug wires.
• Damaged wiring harness.
• Plugged intake air duct or a dirty air filter element. A WOT acceleration from a stop should cause mass air flow parameter to increase from about 2-3.5 grams/second at idle to about 100 grams/second or greater at time of 1-2 shift.

An intermittent malfunction may be caused by a poor connection, rubbed-through wire insulation, or a wire broken inside insulation. Check harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement. Intermittent may also be caused by a fault in MAF sensor circuit. Inspect wiring harness and components for an intermittent condition.