Toyota Tundra. Manual - part 1534

HINT:

TP#1 stands for Throttle Position No. 1, and TP#2 stands for Throttle Position No. 2.

B: Go to step 5

A: Go to next step.

2. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)

a. Disconnect the D9 throttle body connector.

Fig. 87: Identifying Terminals Of D9 Throttle Body And D74 ECM Connectors
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

b. Disconnect the D74 ECM connector.

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

Standard resistance

RESISTANCE SPECIFIED CONDITION

0.7 to 1.3 V (Fail-

safe)

0 to 0.2 V, or 4.5

to 5.0 V

0.7 to 1.3 V (Fail-

safe)

0 to 0.2 V, or 4.5

to 5.0 V

circuit open

or ground

short

0.5 to 1.1 V

2.1 to 3.1 V

3.3 to 4.9 V (Not

fail-safe)

4.6 to 5.0 V (Not

fail-safe)

TP sensor

circuit

normal

Tester Connection

Condition Specified Condition

D9-5 (VC) - D74-80 (VCTA)

Always

Below 1 ohms

D9-6 (VTA) - D74-78 (VTA1)

Always

Below 1 ohms

D9-4 (VTA2) - D74-77 (VTA2)

Always

Below 1 ohms

D9-3 (E2) - D74-79 (ETA)

Always

Below 1 ohms

D9-5 (VC) or D74-80 (VCTA) - Body ground

Always

10 kohms or higher

D9-6 (VTA) or D74-78 (VTA1) - Body ground

Always

10 kohms or higher

D9-4 (VTA2) or D74-77 (VTA2) - Body ground Always

10 kohms or higher

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step.

3. INSPECT ECM (VC VOLTAGE)

a. Disconnect the D9 throttle body connector.

Fig. 88: Identifying Terminals Of D9 Throttle Body Connector
Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

b. Turn the ignition switch to ON.

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

Standard voltage

VOLTAGE SPECIFIED CONDITION

NG: REPLACE ECM (See REMOVAL )

OK: Go to next step.

4. REPLACE THROTTLE BODY ASSEMBLY

a. Replace the throttle body assembly (see REMOVAL ).

5. CHECK WHETHER DTC OUTPUT RECURS (THROTTLE POSITION SENSOR DTCS)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON and turn the Techstream ON.

c. Clear DTCs (see DTC CHECK/CLEAR ).

d. Start the engine.

e. Allow the engine to idle for 15 seconds or more.

f. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

g. Read DTCs.

Tester Connection

Switch Condition Specified Condition

D9-5 (VC) - D9-3 (E2) Ignition switch ON

4.5 to 5.5 V

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

Result

RESULT REFERENCE

B: SYSTEM OK

A: REPLACE ECM (See REMOVAL )

DTC P0121 THROTTLE/PEDAL POSITION SENSOR/SWITCH "A" CIRCUIT
RANGE/PERFORMANCE PROBLEM

DESCRIPTION

Refer to DTC P0120 .

DTC DETECTION CONDITION AND TROUBLE AREA REFERENCE CHART

MONITOR DESCRIPTION

The ECM uses the TP sensor to monitor the throttle valve opening angle.

This sensor transmits two signals: VTA1 and VTA2. VTA1 is used to detect the throttle opening angle and
VTA2 is used to detect malfunctions in VTA1. The ECM performs several checks to confirm the proper
operation of the TP sensor and VTA1.

For each throttle opening angle, a specific voltage difference is expected between the outputs of VTA1 and
VTA2. If the output voltage difference between the two signals deviates from the normal operating range, the
ECM interprets this as a malfunction of the TP sensor. The ECM illuminates the MIL and stores the DTC.

If the malfunction is not repaired successfully, the DTC is stores 2 seconds after the engine is next started.

MONITOR STRATEGY

Result

Proceed to

P0120, P0122, P0123, P0220, P0222, P0223 and/or P2135 are output

No DTC is output

DTC

DTC Detection Condition

Trouble Area

P0121

Difference between VTA1 and
VTA2 voltages less than 0.8 V, or
more than 1.6 V for 2 seconds (1
trip detection logic)

TP sensor (built into throttle body)

Related DTCs

P0121: TP sensor rationality

Required Sensors/Components (Main)

TP sensor

Required Sensors/Components (Related)

Frequency of Operation

Continuous

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

FAIL-SAFE

When this DTC, as well as other DTCs relating to ETCS (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 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.

INSPECTION PROCEDURE

HINT:



This DTC relates to the Throttle Position (TP) sensor.



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.

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0121)

a. Connect the Techstream to the DLC3.

b. Turn the ignition switch to ON.

c. Turn the Techstream ON.

d. Enter the following menus: Powertrain/Engine and ECT/Trouble Codes.

Duration

Within 2 seconds

MIL Operation

Immediate

Sequence of Operation

None

Monitor runs whenever following DTCs
not present

P0120, P0122, P0123, P0220, P0222, P0223, P2135 (Throttle
Position Sensor)

Either of following conditions A or B set -
A. Ignition switch

B. Electric throttle motor power

When either condition below is met:

Difference of TP sensor voltage between VTA and VTA2 x 0.8

More than 1.6 V

Difference of TP sensor voltage between VTA and VTA2 x 0.8

Less than 0.8 V

2009 Toyota Tundra

2009 ENGINE PERFORMANCE Engine Control System (3UR-FBE) - Tundra

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