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
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| 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:
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
Charging System
DTC Code
Detection Item
Warning Indicate
Memory
SAE
See page
P161A87
Lost Communication with Alternator Missing Message
-
DTC stored
...
Precaution
PRECAUTION
1. DOOR CONTROL RECEIVER EXPRESSIONS
(a) The type of door control receiver used on this model differs according to
the specifications of the vehicle. The expressions listed in the table below are
used in this section.
Vehicle Specification
Part Name in Manual
...
How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT
HINT:
Use the following procedure to troubleshoot the LIN communication system.
*: Use the Techstream.
PROCEDURE
1.
VEHICLE BROUGHT TO WORKSHOP
NEXT
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