DTC P1658

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

General Description 

Courtesy of HONDA, U.S.A., INC.

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 electronic throttle control system (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 pedal 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 is applied from the ETCS control relay to the VBDBW 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 stores a DTC.

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

Execution	Once per driving cycle
Sequence	None
Duration	2.0 seconds or more
DTC Type	One drive cycle, MIL on
OBD Status	PASSED/FAILED/NOT COMPLETED (STILL TESTING)

Enable Conditions 

Condition
Vehicle	OFF (LOCK) mode

Malfunction Threshold 

The communication signal is input from the PCM for at least 2.0 seconds after the ETCS control relay is turned off.

Possible Cause 

NOTE:  The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.

• ETCS control relay failure
• ETCS control relay VBDBW line short to ground
• PCM failure

Diagnosis Details 

Conditions for setting the DTC 

When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data 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, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.