Dtc P2118 Throttle Actuator Control Motor Current Range / Performance

Engine. Lexus Gs430, Gs300. Uzs190 Grs190
3Gr-Fe Engine Control System. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

MONITOR DESCRIPTION

FAIL-SAFE

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FUSE (ETCS FUSE)

INSPECT ECM (+BM VOLTAGE)

CHECK HARNESS AND CONNECTOR (ECM - ETCS FUSE, ETCS FUSE - BATTERY)

DTC P2118 Throttle Actuator Control Motor Current Range / Performance


DESCRIPTION

The ETCS (Electronic Throttle Control System) has a dedicated power supply circuit. The voltage (+BM) is monitored and when it is low (less than 4 V), the ECM determines that there is a malfunction in the ETCS and cuts off the current to the throttle actuator.
When the voltage becomes unstable, the ETCS itself becomes unstable. For this reason, when the voltage is low, the current to the throttle actuator is cut. If repairs are made and the system returns to normal, turn the engine switch to off. The ECM then allows the current to flow to the throttle actuator so that it can be restarted.
HINT:
The ETCS does not use a throttle cable.

Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P2118 Throttle Actuator Control Motor Current Range / Performance


DTC No.
DTC Detection Condition
Trouble Area
P2118
Open in ETCS power source (+BM) circuit
(1 trip detection logic)
  1. Open in ETCS power source circuit
  1. ETCS fuse
  1. ECM

MONITOR DESCRIPTION

The ECM monitors the battery supply voltage applied to the throttle actuator.
When the power supply voltage (+BM) drops below 4 V for 0.8 seconds or more, the ECM interprets this as an open in the power supply circuit (+BM). The ECM illuminates the MIL and sets the DTC.
If the malfunction is not repaired successfully, the DTC is set 5 seconds after the engine is next started.

FAIL-SAFE

When this DTC, as well as other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions, is set, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator off, and the throttle valve is returned to a 6° throttle angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing, in accordance with the accelerator pedal opening angle, to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly.
Fail-safe mode continues until a pass condition is detected, and the engine switch is then turned to off.

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P2118 Throttle Actuator Control Motor Current Range / Performance


INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
1.CHECK FUSE (ETCS FUSE)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P2118 Throttle Actuator Control Motor Current Range / Performance

  1. Remove the ETCS fuse from the engine room No. 2 relay block.

  1. Measure the resistance of the ETCS fuse.

    Standard resistance:
    Below 1 Ω

  1. Reinstall the ETCS fuse.



NG
CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED TO FUSE
OK


2.INSPECT ECM (+BM VOLTAGE)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P2118 Throttle Actuator Control Motor Current Range / Performance

  1. Measure the voltage between the terminals of the E7 and E8 ECM connectors.

    Standard voltage:
    Tester Connection
    		Specified Condition
    +BM (E8-5) - E1 (E7-7)
    		9 to 14 V


OK
CHECK FOR INTERMITTENT PROBLEMS
NG


3.CHECK HARNESS AND CONNECTOR (ECM - ETCS FUSE, ETCS FUSE - BATTERY)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P2118 Throttle Actuator Control Motor Current Range / Performance

  1. Check the harness and connector between the ETCS fuse and ECM.

    1. Remove the ETCS fuse from the engine room No. 2 relay block.

    2. Disconnect the E8 ECM connector.

    3. Measure the resistance.

      Standard resistance (Check for open):
      Tester Connection
      		Specified Condition
      ETCS fuse (2) - +BM (E8-5)
      		Below 1 Ω
      Standard resistance (Check for short):
      Tester Connection
      		Specified Condition
      ETCS fuse (2) or +BM (E8-5) - Body ground
      		10 kΩ or higher

    4. Reinstall the ETCS fuse.

    5. Reconnect the ECM connector.

  1. Check the harness and connector between the ETCS fuse and positive battery cable.

    1. Remove the ETCS fuse from the engine room No. 2 relay block.

    2. Disconnect the positive battery cable.

    3. Measure the resistance.

      Standard resistance (Check for open):
      Tester Connection
      		Specified Condition
      Positive battery cable - ETCS fuse (1)
      		Below 1 Ω
      Standard resistance (Check for short):
      Tester Connection
      		Specified Condition
      Positive battery cable or ETCS fuse (1) - Body ground
      		10 kΩ or higher

    4. Reinstall the ETCS fuse.

    5. Reconnect the positive battery cable.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE ECM