Lexus TechDoc

DTC P2102 Throttle Actuator Control Motor Circuit Low
DTC P2103 Throttle Actuator Control Motor Circuit High

for Preparation Click here

DESCRIPTION

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

HINT:

This electronic throttle control system does not use a throttle cable.

DTC No.	DTC Detection Condition	Trouble Area
P2102	Both of the following conditions continue for 2 seconds (1 trip detection logic): (a) Throttle actuator duty ratio is 80% or more (b) Throttle actuator current is below 0.5 A	Open in throttle actuator circuit Throttle actuator ECM
P2103	Either condition is met (1 trip detection logic): Hybrid IC diagnosis signal fails Hybrid IC current limiter port fails	Short in throttle actuator circuit Throttle actuator Throttle valve Throttle body assembly ECM

MONITOR DESCRIPTION

The ECM monitors the electrical current through the electronic actuator, and detects malfunctions and open circuits in the throttle actuator based on this value. If the current is outside the standard range, the ECM determines that there is a malfunction in the throttle actuator. In addition, if the throttle valve does not function properly (for example, stuck on), the ECM determines that there is a malfunction. The ECM then illuminates the MIL and stores a DTC.

Example:

When the electrical current is below 0.5 A and the throttle actuator duty ratio exceeds 80%, the ECM interprets this as the current being outside the standard range, illuminates the MIL and stores a DTC.

MONITOR STRATEGY

Required Sensors/Components (Main)	Throttle actuator (throttle body assembly)
Frequency of Operation	Continuous

CONFIRMATION DRIVING PATTERN

Connect the intelligent tester to the DLC3.
Turn the power switch on (IG) and turn the tester on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
Turn the power switch off and wait for 30 seconds.
Turn the power switch on (IG) and turn the tester on [A].
Put the engine in inspection mode (maintenance mode) (Click here).
Start the engine.
With the vehicle stationary, fully depress the accelerator pedal and quickly release it [B].
Check that 16 seconds or more have elapsed from the instant when the accelerator pedal is first depressed.
Enter the following menus: Powertrain / Engine and ECT / DTC [C].
Read the pending DTCs.
HINT:
1. If a pending DTC is output, the system is malfunctioning.
2. If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
Input the DTC: P2102 or P2103.

Check the DTC judgment result.

Tester Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
UNKNOWN	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] through [C] again.

FAIL-SAFE

When either of these DTCs, as well as other DTCs relating to electronic throttle control system malfunctions is stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator, and the throttle valve is returned to a 5.5° throttle angle by the return spring. The ECM stops the engine and the vehicle can be driven using solely the hybrid system. 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 power switch is then turned off.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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.
The throttle actuator current (Throttle Motor Current) and the throttle actuator duty ratio (Throttle Motor Duty (Open) / Throttle Motor Duty (Close)) can be read using the tester. However, the ECM shuts off the throttle actuator current when the electronic throttle control system malfunctions.

1.INSPECT THROTTLE BODY ASSEMBLY (RESISTANCE OF THROTTLE ACTUATOR)

Inspect the throttle body assembly (Click here).

REPLACE THROTTLE BODY ASSEMBLY (Click here)

OK

2.CHECK HARNESS AND CONNECTOR (THROTTLE BODY ASSEMBLY - ECM)

Disconnect the throttle body assembly connector.

Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
D4-2 (M+) - D27-21 (M+)	Always	Below 1 Ω
D4-1 (M-) - D27-20 (M-)	Always	Below 1 Ω
D4-2 (M+) or D27-21 (M+) - Body ground	Always	10 kΩ or higher
D4-1 (M-) or D27-20 (M-) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.INSPECT THROTTLE BODY ASSEMBLY (VISUALLY CHECK THROTTLE VALVE)

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

REMOVE FOREIGN OBJECT AND CLEAN THROTTLE BODY ASSEMBLY

OK

4.INSPECT THROTTLE BODY ASSEMBLY (THROTTLE VALVE)

Check if the throttle valve opens and closes smoothly.
OK:
Throttle valve opens and closes smoothly.