| Last Modified: 05-13-2024 | 6.11:8.1.0 | Doc ID: RM100000001D0B5 |
| Model Year Start: 2019 | Model: GR Corolla | Prod Date Range: [06/2018 - 03/2019] |
| Title: NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM: Vehicle Speed Signal Circuit between Stereo Component Amplifier and Combination Meter; 2019 - 2020 MY Corolla Corolla Hatchback Corolla HV GR Corolla [06/2018 - 03/2019] | ||
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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 its respective systems based on this pulse signal.
- If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems in the following diagram 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 I4-36 (+S) and body ground. (3) Turn the engine switch on (IG). (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. |
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| NG |
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GO TO METER / GAUGE SYSTEM
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![2019 MY Corolla Corolla Hatchback GR Corolla [06/2018 - 01/2019]; METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM (for Gasoline Model): Speed Signal Circuit](/t3Portal/stylegraphics/info.gif)
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2. |
INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY (INPUT WAVEFORM) |
(a) Check the input waveform.
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*a |
Component with harness connected (Stereo Component Amplifier Assembly) |
- |
- |
(1) Remove the stereo component amplifier assembly with the connector(s) still connected.
(2) Connect an oscilloscope to terminal I68-11 (SPD) and body ground.
(3) Turn the engine switch on (IG).
(4) Turn a wheel slowly.
(5) Check the signal waveform according to the condition(s) in the table below.
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Item |
Condition |
|---|---|
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Measurement terminal |
I68-11 (SPD) - Body ground |
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Tool setting |
5 V/DIV., 20 ms./DIV. |
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Vehicle condition |
Wheel being rotated |
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.
| OK |
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PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE
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| NG |
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REPAIR OR REPLACE HARNESS OR CONNECTOR |
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