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

The electronic throttle control system (ETCS) controls the throttle valve opening. The system is composed of the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the ETCS control relay, the accelerator pedal position (APP) sensor, and the engine control module (ECM)/powertrain control module (PCM). When the driver presses the accelerator pedal, the APP sensor reacts and detects the accelerator opening value. The accelerator pedal opening value is converted to a signal in the APP sensor and transmitted to the ECM/PCM to compute the target position. The ECM/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 ECM/PCM detects a malfunction in the ETCS control relay power switch and a DTC is stored.