| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - LEXUS article in GENERAL INFORMATION. |
Circuit Description
Electric Throttle Control System (ETCS) is composed of throttle motor to operate throttle valve, throttle position sensor to detect opening angle of throttle valve, accelerator pedal position sensor to detect accelerator pedal position, ECM to control ETCS, and one valve type throttle body. ECM controls throttle motor to make throttle valve opening angle correct in response to driving condition. Throttle position sensor which is mounted on throttle body, detects opening angle of throttle valve, and provides feedback to ECM to control throttle motor. If ETCS has a malfunction, throttle valve is locked at a certain opening angle. Also, entire electronically controlled throttle operation is cancelled until system returns to normal and ignition switch is turned off. DTC P2119 is set when throttle opening angle continues to vary greatly from target throttle opening angel. Possible causes are a faulty electric throttle control system and/or faulty ECM.
Diagnostic Aids
Read freeze frame data using hand-held tester or OBD-II scan tool, as freeze frame data records engine conditions when a malfunction is detected. When troubleshooting, it is useful to determine whether vehicle was running or stopped, engine was warmed up or not, air-fuel ratio was lean or rich, etc. at time of malfunction.