Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Vehicle Speed Signal Circuit between Navigation ECU and Combination Meter
DESCRIPTION
The navigation ECU receives a vehicle speed signal from the combination meter 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 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. | CHECK COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM) |
| (a) Check the output waveform. (1) Remove the combination meter assembly with the connector still connected. (2) Connect an oscilloscope to terminal J10-19 (+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. |
|
| NG |  | GO TO METER / GAUGE SYSTEM |
|
| 2. | CHECK NAVIGATION ECU (INPUT WAVEFORM) |
| (a) Check the input waveform. (1) Remove the navigation ECU with the connector(s) still connected. (2) Connect an oscilloscope to terminal J153-9 (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.
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 |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
AVC-LAN Circuit
DESCRIPTION Each unit of the audio and visual system connected to the AVC-LAN (communication bus) transmits switch signals via AVC-LAN communication. If a short to +B or short to ground occurs in the ...
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 ea ...
Other materials:
Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Blind Spot Monitor System: Diagnosis System
DIAGNOSIS SYSTEM DESCRIPTION (a) Blind spot monitor data and Diagnostic Trouble Codes (DTCs) can be read from the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and to perform repairs. CHECK DLC3 (a) Check the DLC ...
Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Clearance Warning Ecu: Removal
REMOVAL CAUTION / NOTICE / HINT The necessary procedures (adjustment, calibration, initialization, or registration) that must be performed after parts are removed and installed, or replaced during clearance warning ECU assembly removal/installation are shown below. Necessary Procedures After Parts R ...
Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual
- For your information
- Pictorial index
- For safety and security
- Instrument cluster
- Operation of each component
- Driving
- Lexus Display Audio system
- Interior features
- Maintenance and care
- When trouble arises
- Vehicle specifications
- For owners
Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual
0.0108