Faulty Electronic Throttle Control System (ETCS) Relay
Electronic Throttle Control System Relay harness is open or shorted
Electronic Throttle Control System Relay circuit poor electrical connection
Faulty Powertrain Control Module (PCM)
Engine Light ON (or Service Engine Soon Warning Light)
The Powertrain Control Module (PCM) controls the throttle valve opening. The system includes 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 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 a DTC is stored.