Last Modified: 11-29-2007 1.6 C
Service Category: Engine/Hybrid System Section: Engine Control
Model Year: 2008 Model: Sequoia Doc ID: RM000000PFU06EX
Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia)

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 opens and closes the throttle valve using gears.

The opening angle of the throttle valve is detected by the Throttle Position (TP) sensor, which is mounted on the throttle body. The TP 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 ETCS (Electronic Throttle Control System) does not use a throttle cable.

DTC No.

DTC Detection Condition

Trouble Area

P2102

Conditions (a) and (b) continue for 2.0 seconds (1 trip detection logic):

(a) Throttle actuator duty ratio 80% or more

(b) Throttle actuator current less than 0.5 A
  • Open in throttle actuator circuit
  • Throttle actuator
  • ECM

P2103

Either of following conditions met (1 trip detection logic):

  • Hybrid IC diagnosis signal failure
  • Hybrid IC current limiter port failure
  • 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 less than 0.5 A and the throttle actuator duty ratio exceeds 80%, the ECM interprets this as the current being outside the standard range, and illuminates the MIL and stores a DTC.

If the malfunction is not repaired successfully, a DTC is stored when the engine is quickly revved to a high rpm several times after the engine is started and has idled for 5 seconds.

MONITOR STRATEGY

Related DTCs

P2102: Throttle actuator current (low current)

P2103: Throttle actuator current (high current)

Required Sensors/Components (Main)

Throttle actuator (throttle body)

Required Sensors/Components (Related)

None

Frequency of Operation

Continuous

Duration

2 seconds: P2102

Within 1 second: P2103

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs not present

None

P2102

Throttle actuator

Activated

Duty-cycle ratio to open throttle actuator

80% or more

Throttle actuator power supply

8 V or more

P2103

Throttle actuator

Activated

Throttle actuator power supply

8 V or more

Battery voltage

8 V or more

Starter

OFF

TYPICAL MALFUNCTION THRESHOLDS

P2102

Throttle actuator current

Less than 0.5 A

P2103

Either of the following conditions is met

Condition 1 or 2

1. Hybrid IC diagnosis signal

Fails 25 times

2. Hybrid IC current limiter port

Fails for 0.6 seconds

FAIL-SAFE

When either of these DTCs, or other DTCs relating to ETCS (Electronic Throttle Control System) malfunctions are 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 7° 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 ignition switch is then turned off.

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

  • Read freeze frame data using the Techstream. Freeze frame data records the engine condition 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.

  • The throttle actuator current (Throttle Motor Current) and the throttle actuator duty ratio (Throttle Motor Open Duty/Throttle Motor Close Duty) can be read using the Techstream. However, the ECM shuts off the throttle actuator current when the ETCS malfunctions.

PROCEDURE

1.

INSPECT THROTTLE BODY (RESISTANCE OF THROTTLE ACTUATOR)


(a) Disconnect the throttle body connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

2 (M+) - 1 (M-)

20°C (68°F)

0.3 to 100 Ω
OK

2.

CHECK HARNESS AND CONNECTOR (THROTTLE ACTUATOR - ECM)


(a) Disconnect the throttle body connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D4-2 (M+) - D56-19 (M+)

Always

Below 1 Ω

D4-1 (M-) - D56-18 (M-)

Always

Below 1 Ω

D4-2 (M+) or D56-19 (M+) - Body ground

Always

10 kΩ or higher

D4-1 (M-) or D56-18 (M-) - Body ground

Always

10 kΩ or higher
OK

3.

INSPECT THROTTLE BODY ASSEMBLY

(a) Check for foreign objects between the throttle valve and the housing.

OK:

No foreign objects between throttle valve and housing.

OK

4.

INSPECT THROTTLE VALVE

(a) Check if the throttle valve opens and closes smoothly.

OK:

Throttle valve opens and closes smoothly.

OK