DTC P1659: Electronic Throttle Control System (ETCS) Control Relay OFF Malfunction: General Description

The powertrain control module (PCM) controls the throttle valve opening. The system is composed of the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the accelerator pedal position (APP) sensor, the electronic throttle control system (ETCS) control relay, and the PCM.

The APP sensor is operated via the throttle cable to determine the accelerator opening value when the driver presses the accelerator pedal. 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 sensor A installed in the throttle body.

When the voltage from the ETCS control relay is not input for a set time after the ETCS control relay is turned on when the ignition is turned on, or when voltage is not applied for a set time when the throttle actuator is operating, a malfunction in the ETCS control relay power switch is detected and a DTC is stored.