Dtc P2102 Throttle Actuator Control Motor Circuit Low

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

DESCRIPTION

MONITOR DESCRIPTION

FAIL-SAFE

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECT THROTTLE BODY (THROTTLE ACTUATOR RESISTANCE)

CHECK WIRE HARNESS (THROTTLE BODY - ECM)

INSPECT THROTTLE BODY

INSPECT THROTTLE VALVE

DTC P2102 Throttle Actuator Control Motor Circuit Low

DTC P2103 Throttle Actuator Control Motor Circuit High


DESCRIPTION

The throttle actuator is operated by the ECM and it opens and closes the throttle valve.
The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the throttle body. The throttle position sensor provides feedback to the ECM. This feedback allows the ECM to control the throttle actuator and monitor the throttle opening angle as the ECM responds to driver inputs.

HINT:
This Electronic Throttle Control System (ETCS) does not use a throttle cable.

DTC No.
DTC Detection Conditions
Trouble Areas
P2102
Following conditions are met for 2 seconds (1 trip detection logic):
  1. Throttle actuator duty-cycle is 80% or more
  2. Throttle actuator current is below 0.5 A or less
  1. Open in throttle actuator circuit
  1. Throttle actuator
  1. ECM
P2103
Either of following conditions is met (1 trip detection logic):
  1. Throttle actuator current 10 A or more (0.1 seconds)
  2. Throttle actuator current 7 A or more (0.6 seconds)
  1. Short in throttle actuator circuit
  1. Throttle actuator
  1. Throttle valve
  1. Throttle body
  1. ECM

MONITOR DESCRIPTION

The ECM monitors the flow of electrical current through the electronic throttle actuator, and detects malfunctions or open circuits in the throttle actuator based on the value of the electrical current. When the current deviates from the standard values, the ECM concludes that there is a fault in the throttle actuator. Or, if the throttle valve is not functioning properly (for example, stuck ON), the ECM concludes that there is a fault and illuminates the MIL and sets a DTC.
Example:
The ECM determines that the current has deviated from the standard values when one of the following is detected: 1) the current is more than 10 A, or 2) the actuator driving duty ratio exceeds 80% and the current is less than 0.5 A. Then the ECM turns on the MIL and a DTC is set.
This monitor runs after the engine is started, idled for 5 seconds and then quickly revved at a high rpm several times.

FAIL-SAFE

If the ETCS has a malfunction, the ECM cuts off current to the throttle actuator. The throttle valve returns to a predetermined opening angle (approximately 16°) by the force of 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 enable the vehicle to continue at a minimal speed.
If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven slowly.
If a "pass" condition is detected and then the engine switch is turned off, the fail-safe operation will stop and the system will return to normal.

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.3Uz-Fe Engine Control System.Sfi System. Dtc P2102 Throttle Actuator Control Motor Circuit Low


INSPECTION PROCEDURE

HINT:
  1. Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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. The throttle actuator current (Throttle Motor) and the throttle actuator duty ratio (Throttle Motor Open Duty / Throttle Motor Close Duty) can be read using the intelligent tester. However the ECM shuts off the throttle actuator current when the ETCS malfunctions.
1.INSPECT THROTTLE BODY (THROTTLE ACTUATOR RESISTANCE)
Lexus Gs430, Gs300. Uzs190 Grs190.3Uz-Fe Engine Control System.Sfi System. Dtc P2102 Throttle Actuator Control Motor Circuit Low

  1. Disconnect the E39 throttle body connector.

  1. Measure the resistance between terminals 1 and 2 of the throttle body.

    Standard resistance:
    0.3 to 100 Ω at 20°C (68°F)


NG
REPLACE THROTTLE BODY
OK


2.CHECK WIRE HARNESS (THROTTLE BODY - ECM)
Lexus Gs430, Gs300. Uzs190 Grs190.3Uz-Fe Engine Control System.Sfi System. Dtc P2102 Throttle Actuator Control Motor Circuit Low

  1. Disconnect the E39 throttle body connector.

  1. Disconnect the E8 ECM connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    E39-1 (M-) - E8-1 (M-)
    		Below 1 Ω
    E39-2 (M+) - E8-2 (M+)
    		Below 1 Ω
    E39-1 (M-) or E8-1 (M-) - Body ground
    		10 kΩ or higher
    E39-2 (M+) or E8-2 (M+) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.INSPECT THROTTLE BODY

  1. Check throttle body for foreign objects.

    OK:
    No foreign objects between the throttle valve and the housing.


NG
REMOVE FOREIGN OBJECT AND CLEAN THROTTLE BODY
OK


4.INSPECT THROTTLE VALVE

  1. Check if the throttle valve can open and close smoothly.

    OK:
    Throttle valve can move smoothly.


NG
REPLACE THROTTLE BODY
OK

REPLACE ECM