speed sensor TOYOTA SEQUOIA 2001 Service Repair Manual

N02332
1
2 3
DI±1634
± DIAGNOSTICSCOMBINATION METER SYSTEM
1828 Author: Date:
2005 SEQUOIA (RM1146U)
3 Inspect vehicle speed sensor.
PREPARATION:
(a) Disconnect the vehicle speed sensor connector.
(b) Connect the positive (+) lead from the battery to terminal
1 and the negative (±) lead to terminal 2.
(c) Connect the positive (+) lead from the tester to terminal
3 and the negative (±) lead to terminal 2.
(d) Rotate the shaft.
CHECK:
Check that voltage between terminals 2 and 3 changes from
approx. 0 V to16 V or more.
OK:
Voltage changes from approx. 0 V to 16 V
HINT:
The voltage should change 4 times for every revolution of the
speed sensor shaft.
NG Replace vehicle speed sensor.
OK

I28569
Combination Meter:
C5±24
I28570
Combination Meter:
C6±12
C6±10
I28573
Vehicle Speed Sensor
Wire Harness Side:
V1
± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±1635
1829 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check harness and connector (Vehicle speed sensor ± combination meter and
vehicle speed sensor ± battery).
PREPARATION:
Disconnect the combination meter connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester connectionConditionSpecified condition
C5±24 ± V1±3AlwaysBelow 1 W
C6±10 ± V1±2AlwaysBelow 1 W
C6±12 ± Body groundAlwaysBelow 1 W
C5±24 ± Body groundAlways10 kW or higher
C6±10 ± Body groundAlways10 kW or higher
CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:
Tester connectionConditionSpecified condition
V1±1 ± Body groundIgnition switch OFFBelow 1 V
V1±1 ± Body groundIgnition switch ON10 to 14 V
NG Repair or replace harness or connector.
OK
Replace combination meter
(See page IN±35).

DIDBR±01
I28195
I28196
I28197
DI±2162
± DIAGNOSTICSNAVIGATION SYSTEM
2356 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DESCRIPTION
1. SYSTEM NORMAL CONDITION CHECK
(a) If the symptom is applicable to any of the following, it is intended behavior, and not a malfunction.
SymptomAnswer
A longer route than expected is chosen.Depending on the road conditions, the navigation ECU may determine that a longer
route is quicker.
Even when distance priority is high, the shortest route is not
shown.Some paths may not be advised due to safety concerns.
When the vehicle is put into motion immediately after the
engine starts, the navigation system deviates from the actu-
al position.If the vehicle starts before the navigation system activates, the system may not
react.
When running on certain types of roads, especially new
roads, the vehicle position deviates from the actual position.When the vehicle is driving on new roads not available on the map disc, the system
attempts to match it to another nearby road, causing the position mark to deviate.
(b) The following symptoms are not a malfunction, but are
caused by errors inherent in the GPS, gyro sensor, speed
sensor, and navigation ECU.
(1) The current position mark may be displayed on a
nearby parallel road.
(2) Immediately after a fork in the road, the current ve-
hicle position mark may be displayed on the wrong
road.
(3) When the vehicle turns right or left at an intersec-
tion, the current vehicle position mark may be dis-
played on a nearby parallel road.

I28203
I28204
I28187
Radio and Display Assy
Navigation ECURadio and Navigation Assy DI±2164
± DIAGNOSTICSNAVIGATION SYSTEM
2358 Author: Date:
2005 SEQUOIA (RM1146U)
(9) When the vehicle runs on the snowy road or a
mountain path with the chains installed or using a
spare tire, the current vehicle position mark may
deviate from the correct position.
(10) When a tire is changed, the current vehicle position
mark may deviate from the correct position.
HINT:
Diameter of the tire may change, causing a speed sensor
error.
Performing the ºtire changeº in calibration mode will allow
the system to correct the current vehicle position faster.
2. Radio and navigation assy outline
Conventionally, 2 separate devices, a ºradio and display assyº and a ºnavigation ECUº are used. This model
has adopted a new type, combining these devices into a single unit.

I28188
GPS satellite
Navigation
Gyro Sensor
ECU GPS Antenna
Receive satellite
radio waveGPS correction
Create the current
vehicle position
tracking data
Navigation screen
Map disc Map matching
correction Detect direction
change Detect vehicle
running distance
Radio and Navigation Assy
Detect the
measurement position
Map scrolling
Map scale switching Map and current vehicle
position data processing Vehicle Speed Sensor
GPS Antenna
Vehicle Speed SensorLocation by
GPS navigation
Gyro Sensor
Location by
autonomous navigation
± DIAGNOSTICSNAVIGATION SYSTEM
DI±2165
2359 Author: Date:
2005 SEQUOIA (RM1146U)
3. Navigation system outline
(a) Vehicle position tracking methods
It is essential that the navigation system correctly tracks the current vehicle position and displays it on
the map. There are 2 methods to track the current vehicle position: autonomous (dead reckoning) and
GPS* (satellite) navigation. Both navigation methods are used in conjunction with each other.
*GPS (Global Positioning System)

I28189
Navigation performed even where the
GPS radio wave does not reach.

In a tunnel

In an indoor parking lot

Between tall buildings

Under an overpass

On a forest or tree±lined path
Autonomous navigation
Autonomous navigation and
GPS navigationGPS satellite DI±2166
± DIAGNOSTICSNAVIGATION SYSTEM
2360 Author: Date:
2005 SEQUOIA (RM1146U)Operation
Description
Vehicle Position Calculation
The navigation ECU calculates the current vehicle position (direction and current
position) using the direction deviation signal from the gyro sensor and the running
distance signal from the vehicle speed sensor and creates the driving route.
Map Display processingThe navigation ECU displays the vehicle track on the map by processing the ve-
hicle position data, vehicle running track, and map data from the map disc.
Map MatchingThe map data from the map disc is compared to the vehicle position and running
track data. Then, the vehicle position is matched with the nearest road.
GPS Correction
The vehicle position is matched to the position measured by GPS. Then, the mea-
surement position data from the GPS unit is compared with the vehicle position and
running track data. If the position is widely different, the GPS measurement position
is used.
Distance Correction
The running distance signal from the vehicle speed sensor includes the error
caused by tire wear and slippage between the tires and road surface. Distance
correction is performed to account for this. The navigation ECU automatically off-
sets the running distance signal to make up for the difference between it and the
distance data of the map. The offset is automatically updated.
HINT:
The combination of autonomous and GPS navigation makes it possible to display the vehicle position even
when the vehicle is in places where the GPS radio wave cannot receive a signal. When only autonomous
navigation is used, however, the mapping accuracy may slightly decline.

I28190
GPS Current longitude/latitude/altitude is determined using the radio wave arrival time from four satellites.
± DIAGNOSTICSNAVIGATION SYSTEM
DI±2167
2361 Author: Date:
2005 SEQUOIA (RM1146U)
(b) Autonomous navigation
This method determines the relative vehicle position based on the running track determined by the
gyro and vehicle speed sensors located in the navigation ECU.
(1) Gyro sensor
Calculates the direction by detecting angular velocity. It is located in the radio and navigation
assy.
(2) Vehicle speed sensor
Used to calculate the vehicle running distance.
(c) GPS navigation (Satellite navigation)
This method detects the absolute vehicle position using radio wave from a GPS satellite.
* GPS satellites were launched by the U.S. Department of Defence for military purposes.
Number of satellitesMeasurementDescription
2 or lessMeasurement impossibleVehicle position cannot be obtained because the number of satellites is not enough.
32±dimensional measure-
ment is possibleVehicle position is obtained based on the current longitude and latitude (This is less precise
than 3±dimensional measurement).
43±dimensional measure-
ment is possibleVehicle position is obtained based on the current longitude, latitude and altitude.

I28191
AActual driving route
Driving route on the display
(Route by estimation)
Roads
The system compares the shape of the roads L1,
L2 and L3 to the estimated running track after the
vehicle makes a right turn. At point A, the vehicle
position differs enough from the shape of L1 that
the display switches to the road L2. Start
Map
Matching
I28192
Vy1
Vx1 Vx2
Vy2 Vx1 (Vy1)
Vx2 (Vy2)
Touch±sensitive switch positionThe touch switch detects the voltage ratio
and calculates the position on the screen. Glass
OuterInner
Contact DI±2168
± DIAGNOSTICSNAVIGATION SYSTEM
2362 Author: Date:
2005 SEQUOIA (RM1146U)
(d) Map matching
The current driving route is calculated by autonomous navigation (according to the gyro sensor and
vehicle speed sensor) and GPS navigation. This information is then compared with possible road
shapes from the map data in the map disc and the vehicle position is set onto the most appropriate
road.
(e) Touch switch
Touch switches are touch±sensitive (interactive) switches operated by touching the screen. When a
switch is pressed, the outer glass bends in to contact the inner glass at the pressed position. By doing
this, the voltage ratio is measured and the pressed position is detected.

I28260
I28261
± DIAGNOSTICSNAVIGATION SYSTEM
DI±2239
2433 Author: Date:
2005 SEQUOIA (RM1146U)
Vehicle position mark deviates greatly
INSPECTION PROCEDURE
1 Check GPS mark.
CHECK:
Check that the GPS mark is displayed.
OK:
The GPS mark is displayed.
NG Go to ºGPS mark is not displayedº in flow chart
(See page DI±2245).
OK
2 Navigation check mode (Vehicle sensors check).
PREPARATION:
Enter the ºNavigation Checkº mode (Vehicle Sensors) (See
page DI±2180).
CHECK:
While driving, compare the ºSPDº indicator to the reading on the
speedometer. Check that these readings are almost the same.
OK:
The readings are almost the same.
NG Go to ºspeed signal circuitº in flow chart
(See page DI±2291).
OK
DIDCW±01

I28261
± DIAGNOSTICSNAVIGATION SYSTEM
DI±2243
2437 Author: Date:
2005 SEQUOIA (RM1146U)
3 Navigation check mode (Vehicle sensors check).
PREPARATION:
Enter the ºNavigation Checkº mode (Vehicle Sensors) (See
page DI±2176).
CHECK:
While driving, compare the ºSPDº indicator to the reading on the
speedometer. Check if these readings are almost the same.
OK:
The readings are almost the same.
NG Go to ºspeed signal circuitº in flow chart
(See page DI±2291).
OK
Proceed to next circuit inspection shown in problem symptoms table (See page DI±2184).