P1659 - FAULT CODE - OBD2

P1659 ACURA, HONDA: ELECTRONIC THROTTLE CONTROL SYSTEM CONTROL RELAY OFF MALFUNCTION

The PCM (Powertrain Control Module) is responsible for throttle valve opening control. For this system, a throttle actuator, throttle valve, TPS (Throttle Position Sensors A and B), APP (Accelerator Pedal Position Sensor), and ETCS relay  (Electronic Throttle Control System) are included.

The APP sensor is driven by a throttle cable that determines the throttle opening value once the pedal is depressed. This value is converted into a signal and sent to the PCM, which, based on this, calculates the target position. The PCM determines the target position of the throttle valve according to the received signal and actuates the throttle actuator to move the valve to the target position.

The actual throttle valve position is determined by the TPS Sensor A, which is installed in the valve body when relay voltage is applied to the IG1ETCS terminal for a specified time after the ETCS relay is turned off. P1659  OBDII fault code is set when the PCM detects a malfunction in the ETCS control relay power switch.

• Check Engine lamp illuminates.
• Limited acceleration.

The reasons why the P1659 OBD2 diagnostic code is stored are:

• ETCS (Electronic Throttle Control System) relay wires could have been damaged.
• ETCS relay circuits may be faulty causing a short or open circuit.
• The Electronic Throttle Control System relay is possibly faulty.

To troubleshoot the DTC P1659 OBDII code you must do the following:

• Consult the Technical Service Bulletins.
• Inspect the ETCS relay circuit wiring and check for damage caused by burns or corrosion. If you find one of these conditions, repair them appropriately.
• Perform voltage tests on the Electronic Throttle Control System relay circuit to verify that they match the manufacturer's specifications. Likewise, check the relay integrity and if you discover damage to any of the relays, make the appropriate corrections.