Lexus ES: 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
| 1. | INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM) |
| (a) Check the output waveform. (1) Remove the combination meter assembly with the connector(s) still connected. (2) Connect an oscilloscope to terminal G17-19 (+S) and body ground. (3) Turn the power 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. |
|
| NG |  | GO TO METER / GAUGE SYSTEM |
|
| 2. | INSPECT STEREO COMPONENT AMPLIFIER ASSEMBLY (INPUT WAVEFORM) |
| (a) Check the input waveform. (1) Remove the stereo component amplifier assembly with the connector(s) still connected. (2) Connect an oscilloscope to terminal G11-17 (SPD) and body ground. (3) Turn the power 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. |
|
| OK | | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
.gif)
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
READ NEXT:
Visual Mute Signal Circuit between Radio Receiver and Multi-display
DESCRIPTION The radio receiver assembly sends a visual mute signal to the multi-display assembly. As a result, a black screen is displayed when the screen changes so that noise and distorted images ar
Voice Guidance does not Function
WIRING DIAGRAM PROCEDURE 1. CHECK VOICE GUIDANCE SETTING (a) Check that the voice guidance settings are not off. OK: Voice guidance settings are not off. NG CHANGE VOICE GUIDANCE SETT
Voice is not Recognized
PROCEDURE 1. CHECK CONDITION (a) While paying attention to the condition of the spoken voice command, perform a voice recognition operation. OK: Voice command is recognized normally. HINT:
SEE MORE:
Installation
INSTALLATION CAUTION / NOTICE / HINT HINT:
Use the same procedure for the RH side and LH side.
The following procedure is for the LH side.
PROCEDURE 1. INSTALL FRONT DOOR OPENING TRIM WEATHERSTRIP (a) Align the alignment mark on the front door opening trim weatherstrip with the flange on the
Remote Service Malfunction
PROCEDURE 1. CHECK CAN COMMUNICATION SYSTEM (a) Connect the Techstream to the DLC3. (b) Turn the engine switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Bus Check. Click here (e) Check that all ECUs and sensors that use CAN communication are connected. Resul
