Note. For information on engine immobilizer system, see COMPUTERIZED ENGINE CONTROLS in THEORY & OPERATION article.
| 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. |
Circuit Description
The TP sensor is a dual variable resistor sensor that monitors throttle opening and TP sensor malfunction. Based on TP sensor signal, ECM determines vehicle driving condition and uses throttle control motor to set throttle angle accordingly. DTC is set after vehicle speed has exceeded 19 MPH even once, output value of throttle position sensor is out of applicable range while vehicle speed is between 0-19 MPH. Possible cause is faulty TP sensor.
Diagnostic Aids
Using scan tool, read freeze frame data. Freeze frame records engine conditions when malfunction is detected.