Toyota Tacoma (2015-2018) Service Manual: Vehicle Speed Signal Circuit between Stereo Component Amplifier and Combination Meter
DESCRIPTION
The stereo component amplifier assembly receives a vehicle speed signal from the combination meter assembly to control the ASL function.
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 the respective systems based on the pulse signal.
- If a short occurs in any of the ECUs or in the wire harness connected to an ECU, related components will not operate normally.
WIRING DIAGRAM
PROCEDURE
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1. |
INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM) |
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(a) Check the output waveform. (1) Remove the combination meter assembly with the connector(s) still connected. (2) Connect an oscilloscope to terminal C9-40 (+S) and body ground. (3) Turn the ignition switch to ON. (4) Turn a wheel slowly. (5) Check the signal waveform according to the condition(s) in the table below.
OK: The waveform is similar to that shown in the illustration. HINT: When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows. Text in Illustration
|
|
| NG | .gif) |
GO TO METER / GAUGE SYSTEM |
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.gif)
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2. |
CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY - COMBINATION METER ASSEMBLY) |
(a) Disconnect the S23 stereo component amplifier assembly connector.
(b) Disconnect the C9 combination meter assembly connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
S23-11 (SPD) - C9-40 (+S) |
Always |
Below 1 Ω |
| OK | |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
AVC-LAN Circuit
DESCRIPTION
Each unit of the navigation system connected to the AVC-LAN (communication bus)
transfers the switch signals using the AVC-LAN.
If a short to +B or short to ground occurs in the AVC-LA ...
Microphone Circuit between Microphone and Radio Receiver
DESCRIPTION
The navigation receiver assembly and telephone microphone assembly are connected
to each other using the microphone connection detection signal lines.
Using this circuit, the navigatio ...
Other materials:
High Power Supply Voltage Malfunction (C1417)
DESCRIPTION
If a malfunction is detected in the power supply circuit, the skid control ECU
(brake actuator assembly) stores this DTC and the fail-safe function prohibits ABS
operation.
This DTC is stored when the +BS terminal voltage deviates from the DTC detection
condition due to a malfunc ...
Installation
INSTALLATION
PROCEDURE
1. INSTALL ENGINE WATER PUMP ASSEMBLY
(a) Install the engine water pump assembly and a new gasket to the timing
chain cover assembly with the 15 bolts.
Torque:
for Bolt A and B :
11 N·m {112 kgf·cm, 8 ft·lbf}
for Bolt C :
21 N·m {214 kgf ...
SRS Warning Light Remains ON
DESCRIPTION
The SRS warning light is located on the combination meter assembly.
When the SRS condition is normal, the SRS warning light illuminates for approximately
6 seconds after the ignition switch is turned from off to ON, and then turns off
automatically.
If there is a malfunction in th ...
