DTC P1658: Electronic Throttle Control System (ETCS) Control Relay ON Malfunction: General Description

The electronic throttle control system controls the throttle valve opening. The system includes the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the electronic throttle control system (ETCS) control relay, the accelerator pedal position (APP) sensor, and the powertrain control module (PCM). When the accelerator pedal is pressed, the APP sensor detects the accelerator opening value. The accelerator pedal opening value is converted to a signal in the APP sensor and transmitted to the PCM to compute the target position. The PCM determines the throttle valve target position according to the signal received and operates the throttle actuator to move the throttle valve to the target position. The actual throttle valve position is determined by TP sensors A and B (installed in the throttle body). When the voltage is applied from the ETCS control relay to the IG1ETCS terminal for a set time after the ETCS control relay is turned off, the PCM detects a malfunction in the ETCS control relay power switch and stores a DTC.