Diagnosis & Repair

NOTE: Read freeze frame data using the hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When trouble shooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

Check if any other DTC is output. If other codes are output, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If only DTC P0121 is output, replace the throttle position sensor. See REMOVAL & INSTALLATION - V6 & V8 article.