TOYOTA SEQUOIA 2001 Service Repair Manual

A21034
T14
Component Side:
M+M± Throttle Control Motor and Sensor
± DIAGNOSTICSENGINE
DI±369
563 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check throttle control motor.
PREPARATION:
Disconnect the throttle control motor and sensor connector.
CHECK:
Measure the resistance between terminals of the throttle con-
trol motor.
OK:
Standard:
Tester ConnectionSpecified Condition
M+ (T14±2) ± M± (T14±1)0.3 to100 W (20°C (68°F))
NG Replace throttle body (See page SF±42).
OK
3 Replace ECM and check DTC (Check if DTC outputs reoccur).
PREPARATION:
(a) Replace ECM.
(b) Clear the DTC (See page DI±43).
(c) Start and warm up the engine.
(d) Run the engine at idle for 15 seconds or more.
CHECK:
Read the DTC using the hand±held tester (See page DI±43).
OK:
No DTC output.
OK System is normal.
NG
Replace throttle body.

DI±370
± DIAGNOSTICSENGINE
564 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P2120 Throttle/Pedal Position Sensor/Switch ºDº
Circuit
DTC P2122 Throttle/Pedal Position Sensor/Switch ºDº
Circuit Low Input
DTC P2123 Throttle/Pedal Position Sensor/Switch ºDº
Circuit High Input
DTC P2125 Throttle/Pedal Position Sensor/Switch ºEº
Circuit
DTC P2127 Throttle/Pedal Position Sensor/Switch ºEº
Circuit Low Input
DTC P2128 Throttle/Pedal Position Sensor/Switch ºEº
Circuit High Input
DTC P2138 Throttle/Pedal Position Sensor/Switch
ºDº/ºEº Voltage Correlation
HINT:
This is the repair procedure for the ºaccelerator pedal position sensorº.
DID8G±01

A19694A19803
5
3.7 to 4.4
2.9 to 3.6
1.6
1.4
025 IC No. 1
IC No. 2
Accelerator Pedal
Position SensorECM
VPA
EPA
VCPA
VPA2
EPA2
VCP2Usable Range
Magnet
Magnet
Accelerator Pedal Position Sensor Output Voltage (V)
: Accelerator Pedal Fully Released
: Accelerator Pedal Fully DepressedAccelerator Pedal Turning Angle (deg)*
2*1
*1
*2
± DIAGNOSTICSENGINE
DI±371
565 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT DESCRIPTION
HINT:

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

This accelerator pedal position sensor is a non±contact type.
The accelerator pedal position sensor is mounted in the accelerator pedal to detect the angle of the accelera-
tor pedal. This sensor is electronically controlled and uses Hall±effect elements.
In the accelerator pedal position sensor, the voltage applied to terminals VPA and VPA2 of the ECM changes
between 0 V and 5 V in proportion to the angle of the accelerator pedal. The VPA is a signal to indicate the
actual accelerator pedal angle and is used for the engine control. VPA2 is used to detect malfunctions of
the sensor itself.
The ECM judges the current angle of the accelerator pedal from these signals input from terminals VPA and
VPA2, and the ECM controls the throttle motor based on these signals.

DI±372
± DIAGNOSTICSENGINE
566 Author: Date:
2005 SEQUOIA (RM1146U)DTC No.
DTC Detection Condition
(Open or short in accelerator pedal position sensor circuit)Main trouble Area
P2120Condition (a) continues for 0.5 seconds or more:
(a) VPA
0.2 V or VPA  4.8 V
Accelerator pedal position sensor

ECM
P2122
Condition (a) and (b) continues for 0.5 seconds or more:
(a) VPA
0.2 V
(b) VPA2  0.97 deg
Accelerator pedal position sensor

VCPA circuit open

VPA circuit open or ground short

ECM
P2123Condition (a) continues for 2.0 seconds or more:
(a) VPA  4.8 V
Accelerator pedal position sensor

EPA circuit open

ECM
P2125
Condition (a) continues for 0.5 seconds or more:
(a) VPA2
0.5 V or VPA2  4.8 V and 0.2 V
VPA
3.45
V
Accelerator pedal position sensor

ECM
P2127
Condition (a) and (b) continues for 0.5 seconds or more:
(a) VPA2
0.5 V
(b) VPA  0.97 deg
Accelerator pedal position sensor

VCP2 circuit open

VPA2 circuit open or ground short

ECM
P2128
Condition (a) and (b) continues for 2.0 seconds or more:
(a) VPA2  4.8 V
(a) 0.2 V
VPA
3.45 V
Accelerator pedal position sensor

EPA circuit open

ECM
P2138
Condition (a) or (b) continues for 2.0 seconds or more:
(a) |VPA ± VPA2|
0.02 V
(b) VPA
0.2 V and VPA2
0.5 V
VPA and VPA2 circuit are short circuited

Accelerator pedal position sensor

ECM
HINT:
After confirming DTC P2120, P2122, P2123, P2125, P2127, P2128 and P2138 use the OBD II scan tool
or the hand±held tester to confirm the accelerator pedal opening percentage.
Accelerator pedal position expressed as voltage
Trouble areaAccelerator pedal completely releasedAccelerator pedal fully depressedTrouble area
ACCEL POS #1ACCEL POS #2ACCEL POS #1ACCEL POS #2
VC circuit open0 to 0.2 V0 to 0.2 V0 to 0.2 V0 to 0.2 V
VPA circuit open or ground short0 to 0.2 V1.2 to 2.0 V0 to 0.2 V3.4 to 5.3 V
VPA2 circuit open or ground short0.5 to 1.1 V0 to 0.2 V2.6 to 4.5 V0 to 0.2 V
E2 circuit open4.5 to 5.5 V4.5 to 5.5 V4.5 to 5.5 V4.5 to 5.5 V
MONITOR DESCRIPTION
When VPA or VPA2 deviates from the standard, or the difference between the voltage outputs of the two
sensors is less than threshold, the ECM concludes that there is a defect in the accelerator pedal position
sensor. The ECM turns on the MIL and a DTC is set.
Example:
When the voltage output of the VPA is below 0.2 V or exceeds 4.8 V.
FAIL SAFE
The accelerator pedal position sensor has two (main and sub) sensor circuits. If a malfunction occurs in ei-
ther of the sensor circuits, the ECM detects the abnormal signal voltage difference between the two sensor
circuits and switches to limp mode. In limp mode, the remaining circuit is used to calculate the accelerator
pedal opening to allow the vehicle to continue driving.
If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal to be fully closed.
In this case, the throttle valve will remain closed as if the engine is idling.
If a ºpassº condition is detected and then the ignition switch is turned OFF, the fail±safe operation will stop
and the system will return to normal condition.

± DIAGNOSTICSENGINE
DI±373
567 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
P2120Accelerator position sensor 1 (VPA) range check
(Fluttering)
P2122Accelerator position sensor 1 (VPA) range check
(Low voltage)
P2123Accelerator position sensor 1 (VPA) range check
(High voltage)
Related DTCsP2125Accelerator position sensor 2 (VPA2) range
check (Fluttering)
P2127Accelerator position sensor 2 (VPA2) range
check (Low voltage)
P2128Accelerator position sensor 2 (VPA2) range
check (High voltage)
P2138Accelerator position sensor correlation range
check
Required sensors/componentsAccelerator position sensor
Frequency of operationContinuous
Duration2 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever these
DTCs are not presentSee page DI±18
Ignition switchON
Throttle control motor powerON

DI±374
± DIAGNOSTICSENGINE
568 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P2120:
Either of the following conditions is metCondition 1 or 2
1. VPA1 voltage when VPA2 is 0.97° or more0.2 V or less
2. VPA1 voltage4.8 V or more
P2122:
VPA1 voltage when VPA2 is 0.97° or more0.2 V or less
P2123:
VPA1 voltage4.8 V or more
P2125:
Either of the following conditions is metCondition 1 or 2
1. VPA2 voltage when VPA1 is 0.97° or more0.5 V or less
2. VPA2 voltage when VPA1 is 0.2 to 3.45 V4.8 V or more
P2127:
VPA2 voltage when VPA1 is 0.97° or more0.5 V or less
P2128:
VPA2 voltage when VPA1 is 0.2 to 3.45 V4.8 V or more
P2138:
Either of the following condition is met:Condition 1 or 2
1. Difference between VPA1 and VPA2 voltage0.02 V or less
2. Both of the following conditions are met:(a) and (b)
(a) VPA1 voltage0.2 V or less
(b) VPA2 voltage0.5 V or less
COMPONENT OPERATING RANGE
ParameterStandard Value
VPA voltageMore than 0.2 V and less than 4.8 V
VPA2 voltageMore than 0.5 V and Less than 4.8 V
Difference between VPA and VPA2 voltagesMore than 0.02 V

A19759
A37
Accelerator Pedal Position Sensor
VPA1
EP1
VCP1G±W
L±YECM
E4
2119
VPA2
EP2
VCP26
5
4
3
2
1G±R
G±B
L±B
L±RE4
E4
E4
E4
E426
27 18
20
VCP2 EPA2 VPA2 VCPAEPAVPA
± DIAGNOSTICSENGINE
DI±375
569 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

FI7052DepressedReleased
DI±376
± DIAGNOSTICSENGINE
570 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held 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, as well as other
data from the time when a malfunction occurred.
1 Connect hand±held tester, and read the voltage for accelerator pedal position
sensor data.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tes-
ter main switch ON.
(c) Enter the following menu: DIAGNOSIS / ENHANCED
OBD II / DATA LIST / ETCS / ACCEL POS #1 and ACCEL
POS #2.
CHECK:
Read the voltage for the accelerator pedal position sensor data.
OK:
Standard:
Accelerator pedalACCEL POS #1ACCEL POS #2
Released0.5 to 1.1 V1.2 to 2.0 V
Depressed2.6 to 4.5 V3.4 to 5.3 V
OK Go to step 5.
NG

A21022
Wire Harness Side:
A37
Accelerator Pedal Position Sensor
VCP2
EPA2
VPA2
VCPAEPAVPA
B17417
E4VPA2
VCPAVPA
EPA2
EPAVCP2
± DIAGNOSTICSENGINE
DI±377
571 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check for open and short in harness and connector in VCPA, VCP2, VPA, VPA2
EPA and EPA2 circuit between ECM and accelerator pedal position sensor.
PREPARATION:
(a) Disconnect the A37 accelerator pedal position sensor
connector.
(b) Disconnect the E4 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
VPA (A37±6) ± VPA (E4±18)Below 1 W
EPA (A37±5) ± EPA (E4±20)Below 1 W
VCPA (A37±4) ± VCPA (E4±26)Below 1 W
VPA2 (A37±3) ± VPA2 (E4±19)Below 1 W
EPA2 (A37±2) ± EPA2 (E4±21)Below 1 W
VCP2 (A37±1) ± VCP2 (E4±27)Below 1 W
VPA (A37±6) or VPA (E4±18) ±
Body ground10 kW or higher
EPA (A37±5) or EPA (E4±20) ±
Body ground10 kW or higher
VCPA (A37±4) or VCPA (E4±26) ±
Body ground10 kW or higher
VPA2 (A37±3) or VPA2 (E4±19) ±
Body ground10 kW or higher
EPA2 (A37±2) or EPA2 (E4±21) ±
Body ground10 kW or higher
VCP2 (A37±1) or VCP2 (E4±27) ±
Body ground10 kW or higher
NG Repair or replace harness and connector.
OK

B17448
EPA (±)VCPA (+)
EPA2 (±)
VCP2 (+) Accelerator Pedal
Position Sensor
Connector
E4
A37
DI±378
± DIAGNOSTICSENGINE
572 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check voltage between terminals VCPA and EPA, and VCP2 and EPA2 of ECM
terminals.
PREPARATION:
(a) Turn the ignition switch ON.
(b) Disconnect the A37 accelerator pedal position sensor
connector.
CHECK:
Measure the voltage between the specified terminals of the E4
ECM connector.
OK:
Standard:
Tester ConnectionSpecified Condition
VCPA (E4±26) ± EPA (E4±20)4.5 to 5.5 V
VCP2 (E4±27) ± EPA2 (E4±21)4.5 to 5.5 V
NG Replace ECM (See page SF±80).
OK
4 Replace accelerator pedal assembly (See page SF±78).
Go