Toyota Tundra. Manual — part 1348

P0120:

TYPICAL MALFUNCTION THRESHOLDS - P0120

P0122:

TYPICAL MALFUNCTION THRESHOLDS - P0122

P0123:

TYPICAL MALFUNCTION THRESHOLDS - P0123

P0220:

TYPICAL MALFUNCTION THRESHOLDS - P0220

P0222:

TYPICAL MALFUNCTION THRESHOLDS - P0222

P0223:

TYPICAL MALFUNCTION THRESHOLDS - P0223

P2135 Case 1:

TYPICAL MALFUNCTION THRESHOLDS - P2135 CASE 1

P2135 Case 2:

TYPICAL MALFUNCTION THRESHOLDS - P2135 CASE 2

COMPONENT OPERATING RANGE

COMPONENT OPERATING RANGE

VTA1 voltage

0.2 V or less, or 4.535 V or higher

VTA1 voltage

0.2 V or less

VTA1 voltage

4.535 V or higher

VTA2 voltage

1.75 V or less, or 4.8 V or higher

VTA2 voltage

1.75 V or less

VTA2 voltage when VTA1 0.2 V or higher, and 2.02 V or less

4.8 V or higher

Difference between VTA1 and VTA2 voltages

0.02 V or less

VTA1 voltage

0.2 V or less

VTA2 voltage

1.75 V or less

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

FAIL-SAFE

When any of these DTCs, as well as other DTCs relating to ETCS (Electronic Throttle Control System)
malfunctions are set, 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

Fig. 77: DTC P0120 Throttle / Pedal Position Sensor / Switch "A" Circuit Malfunction - Wiring Diagram

INSPECTION PROCEDURE

HINT:



These DTCs relate 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. READ VALUE USING TECHSTREAM (THROTTLE POSITION)

a. Connect the Techstream to the DLC3.

VTA1 voltage

0.69 to 4.05 V

VTA2 voltage

2.25 to 4.8 V

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

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

c. Enter the following menus: Powertrain/Engine and ECT/Data List/ETCS/Throttle Position No.1

and Throttle Position No.2.

d. Check the values displayed on the Techstream.

Result

RESULT REFERENCE

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.

b. Disconnect the D74 ECM connector.

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

Standard resistance

STANDARD RESISTANCE SPECIFICATION

TP#1 (VTA1)

When

Accelerator

Pedal Released

TP#2 (VTA2)

When

Accelerator

Pedal Released

TP#1 (VTA1)

When

Accelerator

Pedal Depressed

TP#2 (VTA2)

When

Accelerator

Pedal Depressed

Trouble

Area

Proceed

To

0 to 0.2 V

0 to 0.2 V

0 to 0.2 V

0 to 0.2 V

VC circuit

open

A

4.5 to 5.0 V

4.5 to 5.0 V

4.5 to 5.0 V

4.5 to 5.0 V

E2 circuit

open

A

0 to 0.2 V, or 4.5

to 5.0 V

2.4 to 3.4 V (Fail-

safe)

0 to 0.2 V, or 4.5

to 5.0 V

2.4 to 3.4 V (Fail-

safe)

VTA1

circuit open

or ground

short

A

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

VTA2

circuit open

or ground

short

A

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

B

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

Tester Connection

Condition Specified Condition

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

Always

Below 1 ohms

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra

Fig. 78: Identifying D9 Throttle Body & D74 ECM Connectors

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR

OK : Go To Next Step

3. INSPECT ECM (VC VOLTAGE)

a. Disconnect the D9 throttle body connector.

b. Turn the ignition switch to ON.

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

Standard voltage

STANDARD VOLTAGE SPECIFICATION

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

Tester Connection

Switch Condition Specified Condition

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

4.5 to 5.5 V

2008 Toyota Tundra

2008 ENGINE PERFORMANCE Engine Control System (2UZ-FE) - Tundra