speed sensor TOYOTA SEQUOIA 2001 Service Owner's Manual

DI±72
± DIAGNOSTICSENGINE
266 Author: Date:
2005 SEQUOIA (RM1146U)P2445
(DI±426)
Secondary Air Injection System
Pump Stuck On Bank 1

Air pump fuse

Vacuum hose

Air pump assembly

Open in air pump circuit

Air injection system piping

Pressure sensor

Open or short in pressure sensor circuit

ECM

P2610
(DI±442)ECM/PCM Internal Engine Off
Timer Performance
ECM
P2714
(DI±656)Pressure Control Solenoid ºDº
Performance (Shift Solenoid
Valve SLT)

Electronic control automatic transmission (ECT)
P2716
(DI±662)Pressure Control Solenoid ºDº
Electrical (Shift Solenoid Valve
SLT)

Electronic control automatic transmission (ECT)
P2740
(DI±666)Transmission Fluid Temperature
Sensor ºBº Circuit
Electronic control automatic transmission (ECT)
P2742
(DI±666)Transmission Fluid Temperature
Sensor ºBº Circuit Low Input
Electronic control automatic transmission (ECT)
2743
(DI±666)Transmission Fluid Temperature
Sensor ºBº Circuit High Input
Electronic control automatic transmission (ECT)
P2757
(DI±672)
Torque Converter clutch Pres-
sure Control Solenoid Perfor-
mance (Shift Solenoid Valve
SLU)

Electronic control automatic transmission (ECT)
P2759
(DI±680)Torque Converter clutch Pres-
sure Control Solenoid Electrical
(Shift Solenoid Valve SLU)

Electronic control automatic transmission (ECT)
P2772
(DI±685)Transfer L4 SW Circuit
Electronic control automatic transmission (ECT)
P2A00
(DI±451)A/F Sensor Circuit Slow Re-
sponse (Bank 1 Sensor 1)
Open or short in A/F sensor (sensor 1) circuit

A/F sensor (sensor 1)

ECM

P2A03
(DI±451)A/F Sensor Circuit Slow Re-
sponse (Bank 2 Sensor 1)
Open or short in A/F sensor (sensor 1) circuit

A/F sensor (sensor 1)

ECM

B2799
(DI±1580)Engine Immobilizer System Mal-
function
Immobilizer system±
U0001
(DI±444)High Speed CAN Communica-
tion Bus
ECM
*1: ± .... MIL does not light up.  .... MIL lights up.
*2: MIL lights up or blinks.

DID82±01
A20891
Mass Air Flow Sensor Crankshaft Position Sensor
Actual Valve TimingCorrection Target Valve Timing
Feedback
Duty Control ECM
Camshaft Timing
Oil Control
Valve (OCV)
Vehicle Speed Signal Engine Coolant Temp. Sensor Throttle Position Sensor
Camshaft Position Sensor
± DIAGNOSTICSENGINE
DI±73
267 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT INSPECTION
DTC P0010 Camshaft Position ºAº Actuator circuit
(Bank 1)
DTC P0020 Camshaft Position ºAº Actuator circuit
(Bank 2)
CIRCUIT DESCRIPTION
The Variable Valve Timing (VVT) system includes the ECM, the Oil Control Valve (OCV) and the VVT control-
ler. The ECM sends a target ºduty±cycleº control signal to the OCV. This control signal, applied to the OCV,
regulates the oil pressure supplied to the VVT controller. Camshaft timing control is performed based on en-
gine operation conditions such as intake air volume, throttle position and engine coolant temperature.
The ECM controls the OCV, based on the signals output from the sensors. The VVT controller regulates the
intake camshaft angle using oil pressure through the OCV. As a result, the relative position between the cam-
shaft and the crankshaft is optimized, and the engine torque improves, fuel economy improves, and exhaust
emissions decrease under overall driving conditions. Also, the ECM detects the actual valve timing using
signals from the camshaft position sensor and the crankshaft position sensor, and performs feedback con-
trol. This is how target valve timing is verified by the ECM.
DTC No.DTC Detecting ConditionTrouble Area
P0010
P0020Open or short in OCV circuit

Open or short in OCV circuit

OCV

ECM

± DIAGNOSTICSENGINE
DI±85
279 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0016 Crankshaft Position ± Camshaft Position
Correlation (Bank 1 Sensor A)
DTC P0018 Crankshaft Position ± Camshaft Position
Correlation (Bank 2 Sensor A)
CIRCUIT DESCRIPTION
VVT sensor (VVL or VVR signal) consist of a signal plate and pickup coil.
The VVL or VVR signal plate has 1 tooth on its outer circumference and is mounted on the intake camshafts.
When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.
The actual camshaft angle is detected by the VVT sensor and it provides feedback to the ECM to control
the intake valve timing in response to during condition.
DTC No.DTC Detecting ConditionTrouble Area
No VVT sensor signal to ECM during cranking at 4 sec. or
more
P0016
P0018No VVT sensor signal to ECM with 5 sec. or more engine
speed 600 rpm or more
Open or short in VVT sensor circuit

VVT sensor

ECMP0018
While the crankshaft rotates twice, VVT sensor signal will be
input to ECM 5 times
ECM
MONITOR DESCRIPTION
The ECM optimizes the valve timing using the VVT (Variable Valve Timing) system to control the intake valve
camshaft. The VVT system includes the ECM, the OCV (Oil Control Valve) and the VVT controller. The ECM
sends a target duty±cycle control signal to the OCV. This control signal, applied to the OCV, regulates the
oil pressure supplied to the VVT controller. The VVT controller can advance or retard the intake valve cam-
shaft. The ECM calibrates the valve timing of the VVT system by setting the camshaft to the maximum retard
angle when the engine is idle. The ECM closes the OCV to retard the cam. The ECM stores this value as
VVT learning value (When the difference between the target valve timing and the actual valve timing is 5
degrees or less, the ECM stores this in its memory.).
If the learning value meets both of the following conditions ((a) and (b)), the ECM interprets this as a defect
in the VVT system and sets a DTC.
(a) VVT learning value is less than 20°CA (Crankshaft Angle) or more than 39°CA.
(b) Above condition continues for more than 18 sec.
DIAOO±02

± DIAGNOSTICSENGINE
DI±95
289 Author: Date:
2005 SEQUOIA (RM1146U)DTC No.
DTC Detecting ConditionTrouble Area
P0037Heater current is 0.25 A or less when the heater operates with

Open in heater circuit of heated oxygen sensor

Heated ox
ygen sensor heaterP0037
P0057
Heater current is 0.25 A or less when the heater o erates with
more than 10.5 V positive battery voltage

Heated oxygen sensor heater

EFI relay

ECM
P0038
P0058When heater operates, heater current exceeds 2.0 A

Short in heater circuit of heated oxygen sensor

Heated oxygen sensor heater

EFI relay

ECM
HINT:

Bank 1 refers to bank that includes cylinder No. 1.

Bank 2 refers to bank that does not includes cylinder No. 1.

Sensor 1 refers to the sensor closer to the engine assembly.

Sensor 2 refers to the sensor farther away from the engine assembly.
MONITOR DESCRIPTION
The sensing portion of the heated oxygen sensor has a zirconia element which is used to detect oxygen
concentration in the exhaust. If the zirconia element is at the proper temperature and difference of the oxy-
gen concentration between the inside and outside surface of sensor is large, the zirconia element will gener-
ate voltage signals. In order to increase the oxygen concentration detecting capacity in the zirconia element,
the ECM supplements the heat from the exhaust with heat from a heating element inside the sensor. When
current in the sensor is out of the standard operating range, the ECM interprets this as a fault in the heated
oxygen sensor and sets a DTC.
Example:
The ECM will set a high current DTC if the current in the sensor is more than 2.0 A when the heater is OFF.
Similarly, the ECM will set a low current DTC if the current is less than 0.3 A when the heater is ON.
MONITOR STRATEGY
P0037Rear HO2S heater (Bank 1) range check (Low
Current)
RltdDTC
P0038Rear HO2S heater (Bank 1) range check (High
Current)
Related DTCs
P0057Rear HO2S heater (Bank 2) range check (Low
Current)
P0058Rear HO2S heater (Bank 2) range check (High
Current)
Rid / tMain sensors/componentsHO2S heaterRequired sensors/componentsRelated sensors/componentsVehicle speed sensor (VSS)
Frequency of operationContinuous
Duration0.3 sec.
MIL operationImmediate
Sequence of operationNone

± DIAGNOSTICSENGINE
DI±103
297 Author: Date:
2005 SEQUOIA (RM1146U)
HINT:
After confirming DTC P0100, P0102 or P0103, use the hand±held tester or the OBD II scan tool to confirm
the MAF ratio from the ALL menu (to reach the ALL menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST
/ ALL).
Mass Air Flow Value (gm/sec.)Malfunction
Approx. 0.0
Mass air flow meter power source circuit open

VG circuit open or short
271.0 or more
EVG circuit open
MONITOR DESCRIPTION
If there is a defect in the MAF (Mass Air Flow) meter or an open or short circuit, the voltage level will deviate
outside the normal operating range. The ECM interprets this deviation as a defect in the MAF meter and sets
a DTC.
Example:
When the MAF meter voltage output is less than 0.2 V, or more than 4.9 V, and if either the condition contin-
ues for more than 3 sec.
MONITOR STRATEGY
P0100Mass air flow meter circuit range check
(Fluttering)
Related DTCsP0102Mass air flow meter circuit range check
(Low voltage)
P0103Mass air flow meter circuit range check
(High voltage)
Required sensors/componentsMass air flow meter
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate (When engine speed is at less than 4,000 rpm)
2 driving cycles (When engine speed is at 4,000 rpm or more)
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these
DTCs are not presentSee page DI±18
The typical enabling condition is not avail-
able±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P0100:
Mass air flow meter voltageLess than 0.2 V, or more than 4.9 V
P0102:
Mass air flow meter voltageLess than 0.2 V
P0103:
Mass air flow meter voltageMore than 4.9 V

DI±110
± DIAGNOSTICSENGINE
304 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0101 Mass or Volume Air Flow Circuit Range/
Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0100, P0102 and P0103 on page DI±102.
DTC No.DTC Detecting ConditionTrouble Area
P0101
After engine is warmed up, conditions (a), (b), (c) and (d) con-
tinue for more than 10 seconds:
(2 trip detection logic)
(a) Throttle valve fully closed
(b) Voltage output of the mass air flow meter is more than 2.2
V.
(c) Engine coolant temperature is more than 70 °C (158 °F).
(d) Engine speed is less than 2,000 rpm.

Mass air flow meter
Conditions (a), (b) and (c) continue for more than 10 seconds
at engine speed: (2 trip detection logic)
(a) Engine speed is more than 300 rpm.
(b) Voltage output of the mass air flow meter is less than 1.0 V.
MONITOR DESCRIPTION
The MAF (Mass Air Flow) meter helps the ECM calculate the amount of air flowing through the throttle valve.
The ECM uses this information to determine the fuel injection time and provide a proper air fuel ratio. Inside
the MAF meter, there is a heated platinum wire exposed to the flow of intake air. By applying a specific current
to the wire, the ECM heats this wire to a given temperature. The flow of incoming air cools the wire and an
internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the volt-
age applied to these components in the MAF meter. The voltage level is proportional to the air flow through
the MAF meter. The ECM interprets this voltage as the intake air amount. If there is a defect in the MAF meter
or an open or short circuit, the voltage level will deviate outside the normal operating range. The ECM inter-
prets this deviation as a defect in the MAF meter and sets a DTC.
Example:
If the voltage is more than 2.2 V at idle or less than 1.0 V at idle OFF, the ECM interprets this as a defect
in the MAF meter and sets a DTC.
MONITOR STRATEGY
RltdDTCP0101Mass air flow meter rationality (Low voltage)Related DTCsP0101Mass air flow meter rationality (High voltage)
Main sensors/componentsMass air flow meter
Required sensors/componentsRelated sensors/componentsEngine speed sensor, Engine coolant tempera-
ture sensor, Throttle position sensor
Frequency of operationContinuous
Duration10 sec.
MIL operation2 driving cycles
Sequence of operationNone
DI3HM±13

± DIAGNOSTICSENGINE
DI±111
305 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
High voltage:
Engine speed±2,000 rpm
MAF meter voltage±4.9 V
Engine coolant temperature70C (158F)±
Low voltage:
Engine speed300 rpm±
MAF meter voltage0.2 V±
Fuel cutOFF
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Mass air flow meter voltage (High voltage)More than 2.2 V (varies with throttle position sensor voltage)
Mass air flow meter voltage (Low voltage)Less than 1.0 V (varies with throttle position sensor voltage)

DI±126
± DIAGNOSTICSENGINE
320 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Case 1 (When temperature is fixed between 35C (95F) and 60C (140F)):
Cumulative idle off period250 sec.±
Speed increase 30 km/h (18.6 mph) or
more10 times±
Engine coolant temperature35C (95F)60C (140F)
Intake air temperature±6.7C (20F)±
Case 2 (When temperature is fixed at 60C (140F) or more):
Engine coolant temperature at engine
start60C (140F)±
Intake air temperature±6.7C (20F)±
Stop and goOnce or more (Stop for 20 sec. or more and accelerate to more than 70 km/h (43.5 mph)
with in 40 sec.)
Steady driving and stop *Once or more
*: Vehicle is driven by 65 km/h (40.4 mph) or more for 30 sec. or more and the vehicle speed reaches 70
km/h (43.5 mph). The vehicle is decelerated from 65 km/h (40.4 mph) to 3 km/h (1.86 mph) or less within
35 sec. and stopped for 10 sec.
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Case1 (When temperature is fixed between 35C (95F) and 60C (140F)):
Change of engine coolant temperature valueLess than 3C (5.4F)
Case2 (When temperature is fixed at 60C (140F) or more):
Change of engine coolant temperature value1C (1.8F) or less
COMPONENT OPERATING RANGE
Standard Value
Engine coolant temperature changes with the actual engine coolant temperature.
INSPECTION PROCEDURE
HINT:

If DTC P0115, P0116, P0117, P0118 and P0125 are output simultaneously, ECT sensor circuit may
be open or shorted. Perform the troubleshooting of DTC P0115, P0117 or P0118 first.

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.
Replace engine coolant temperature sensor.

DI±130
± DIAGNOSTICSENGINE
324 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR DESCRIPTION
The ECM uses throttle position sensor to monitor the throttle valve opening angle.
(a) There is an expected specific voltage difference between VTA1 and VTA2 for each throttle opening
angle.

If the difference between VTA1 and VTA2 is incorrect the ECM interprets this as a fault and will set a
DTC.
(b) VTA1 and VTA2 each have a specific voltage operating range.

If VTA1 or VTA2 is out of the normal operating range the ECM interprets this as a fault and will set a
DTC.
(c) VTA1 and VTA2 should never be close to the same voltage levels.

If VTA1 is within the range of ± 0.02 V of VTA2 the ECM interprets this as a short circuit in the throttle
position sensor system and will set a DTC.
FAIL SAFE
If the ETCS (Electronic Throttle Control System) has a malfunction, the ECM cuts off current to the throttle
control motor. The throttle control valve returns to a predetermined opening angle (approximately 16°) by
the force of the return spring. The ECM then adjusts the engine output by controlling the fuel infection (inter-
mittent fuel±cut) and ignition timing in accordance with the accelerator pedal opening angle to enable the
vehicle to continue at a minimum speed.
If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven slowly.
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.
MONITOR STRATEGY
P0120Throttle position sensor (sensor 1) range check
(Fluttering)
P0122Throttle position sensor (sensor 1) range check
(Low voltage)
P0123Throttle position sensor (sensor 1) range check
(High voltage)
Related DTCsP0220Throttle position sensor (sensor 2) range check
(Fluttering)
P0222Throttle position sensor (sensor 2) range check
(Low voltage)
P0223Throttle position sensor (sensor 2) range check
(High voltage)
P2135Throttle position sensor range check (Correla-
tion)
Required sensors/componentsThrottle position sensor
Frequency of operationContinuous
Duration
Accelerator pedal ON: 2 sec.
Accelerator pedal OFF: 10 sec.
P2135: 0.5 sec. or 0.4 sec.
MIL operationImmediate
Sequence of operationNone

± DIAGNOSTICSENGINE
DI±137
331 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0121 Throttle/Pedal Position Sensor/Switch ºAº
Circuit Range/Performance Problem
HINT:
This is the purpose of the ºthrottle position sensorº.
CIRCUIT DESCRIPTION
Refer to DTC P0120 on page DI±127.
DTC No.DTC Detecting ConditionTrouble Area
P0121
Condition (a) continues for 2.0 sec.:
(a) Difference between VTA1 and VTA2 deviates from the
threshold
Throttle control motor and sensor
MONITOR DESCRIPTION
The ECM uses throttle position sensor to monitor the throttle valve opening angle.
This sensor includes two signals, VTA1 and VTA2. VTA1 is used to detect the throttle opening angle and
VTA2 is used to detect malfunctions in VTA1. There are several checks that the ECM performs confirm prop-
er operation of the throttle position sensor and VTA1.
There is a specific voltage difference expected between VTA1 and VTA2 for each throttle opening angle.
If the voltage output difference of the VTA1 and VTA2 deviates from the normal operating range, the ECM
interprets this as a malfunction of the throttle position sensor. The ECM will turn on the MIL and a DTC is
set.
FAIL SAFE
If the ETCS (Electronic Throttle Control System) has a malfunction, the ECM cuts off current to the throttle
control motor. The throttle control valve returns to a predetermined opening angle (approximately 16°) by
the force of the return spring. The ECM then adjusts the engine output by controlling the fuel infection (inter-
mittent fuel±cut) and ignition timing in accordance with the accelerator pedal opening angle to enable the
vehicle to continue at a minimum speed.
If the accelerator pedal is depressed firmly and slowly, the vehicle can be driven slowly.
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.
MONITOR STRATEGY
Related DTCsP0121Throttle position sensor rationality
Required sensors/componentsThrottle position sensor
Frequency of operationContinuous
Duration2 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
VTA2 voltage±4.6 V
DI3HR±14