DTC Advanced Diagnostics: P1659 (1.5L Engine)
DTC P1659: Electronic Throttle Control System (ETCS) Control Relay OFF 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 PGM-FI subrelay, the accelerator pedal position (APP) sensor A/B, and the powertrain control module (PCM). When the accelerator pedal is pressed, the APP sensor A/B detects the accelerator pedal opening value. The accelerator pedal opening value is converted to a signal in the APP sensor A/B 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 PGM-FI subrelay is not input for a set time after the PGM-FI subrelay is turned on when the vehicle is turned to the ON mode, the PCM detects a malfunction in the PGM-FI subrelay power switch and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 200 milliseconds or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| 12 volt battery voltage [Battery] | 10 V | - |
| Vehicle | ON mode | |
[ ]: HDS Parameter
Malfunction Threshold
The power supply voltage is not applied from the PGM-FI subrelay for at least 200 milliseconds.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- PGM-FI subrelay failure
- Fuse failure
- PGM-FI subrelay FI_SUB_RLY_OUT line open
- PGM-FI subrelay FI_SUB_RLY_CL- line open
- PCM internal circuit failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.