| Last Modified: 11-29-2007 | 1.6 J | |
| Service Category: Audio/Visual/Telematics | Section: Navigation/Multi Info Display | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000002OLC00FX |
| Title: NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM: DESCRIPTION (2008 Sequoia) | ||
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Vehicle Speed Signal Circuit between Navigation Receiver Assembly and Combination Meter |
DESCRIPTION
This circuit sends a speed signal from the combination meter to the navigation receiver assembly.
HINT:
- A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls its respective system based on the pulse signal.
- If a short occurs in any of the ECUs or in the wire harness connected to an ECU, both systems in the diagram below will not operate normally.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
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1. |
CHECK OPERATION OF SPEEDOMETER |
(a) Drive the vehicle and check if the function of the speedometer in the combination meter is normal.
OK:
Actual vehicle speed and the speed indicated on the speedometer are the same.
HINT:
-
The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, refer to "Operation Check" in the meter/gauge system
.
- The vehicle speed sensor is functioning normally when the indication on the speedometer is normal.
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2. |
INSPECT COMBINATION METER ASSEMBLY (SPEED SIGNAL) |
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(a) Disconnect the I6 navigation receiver assembly connector. |
(b) Jack up the drive wheels.
(c) Move the shift lever to the neutral position.
(d) Turn the ignition switch to ON.
(e) Using an oscilloscope, check the signal waveform of the meter.
Waveform
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Terminal Connections |
I6-3(SPD) - Body ground |
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Tester Range |
5 V/DIV., 20 msec./ DIV. |
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Vehicle Condition |
Drive vehicle at 20 km/h (12 mph) |
HINT:
As the vehicle speed increases, the wavelength shortens.
OK:
Voltage pulses as shown in the illustration
(f) Reconnect the navigation receiver assembly connector.
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3. |
CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER - COMBINATION METER) |
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(a) Disconnect the I6 navigation receiver assembly connector. |
(b) Disconnect the H37 combination meter assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
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Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
I6-3 (SPD) - H37-35 (+S) |
Always |
Below 1 Ω |
|
I6-3 (SPD) - Body ground |
Always |
10 kΩ or higher |
(d) Reconnect the navigation receiver assembly connector.
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