Advanced Diagnostics

Advanced Diagnostics

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






General Description
The electronic throttle control system (ETCS) controls the throttle valve opening. The system includes 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 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 from the ETCS control relay is not input for a set time after the ETCS control relay is turned on when the ignition switch is turned to ON (II), 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.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
The voltage is not applied from the throttle actuator controller relay for at least 200 milliseconds.

Diagnosis Details

Conditions for illuminating the MIL
When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the PCM memory.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the diagnostic runs. The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.