Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Diagnosis System
DIAGNOSIS SYSTEM
DESCRIPTION
When troubleshooting a vehicle with the diagnosis system, the only difference from the usual troubleshooting procedure is connecting the Techstream to the vehicle and reading various data output from the vehicle's skid control ECU (brake actuator assembly).
The skid control ECU (brake actuator assembly) records DTCs when the ECU detects a malfunction in the ECU itself or in its circuits.
To check the DTCs, connect the Techstream to the DLC3 on the vehicle. The Techstream enables you to clear the DTCs, activate the various actuators, and check the Freeze Frame Data and Data List.
(a) Check the battery voltage.
Standard voltage:
11 to 14 V
If the voltage is below 11 V, recharge the battery before proceeding to the next step.
(b) Check the DLC3.
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DIAGNOSIS
(a) If a malfunction occurs in one part of the system, the skid control ECU (brake actuator assembly) illuminates the warning light corresponding to the malfunctioning system (ABS warning light, brake system warning light or slip indicator light).
(b) The DTCs are simultaneously stored in memory. The DTCs can be read by connecting the Techstream.
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(c) This system has a Dealer Mode (Signal Check) function.
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WARNING LIGHT AND INDICATOR LIGHT INITIAL CHECK
(a) When the engine switch is turned on (IG), check that the ABS warning light, brake warning light, VSC OFF indicator light, slip indicator light, brake hold standby indicator light and brake hold operated indicator light come on for approximately 3 seconds.
HINT:
- When the brake fluid level is low, the brake system warning light comes on.
- If a light does not illuminate, check the communication line between the combination meter assembly and skid control ECU (brake actuator assembly).
- If the ABS warning light or slip indicator light remains illuminated after approximately 3 seconds check for DTCs and check the corresponding code. If no DTC is output, check the communication line between the combination meter assembly and skid control ECU (brake actuator assembly).
| Trouble Area | See procedure |
|---|---|
| ABS warning light circuit (Remains on) | |
| ABS warning light circuit (Does not come on) | |
| Brake warning light circuit (Remains on) | |
| Brake warning light circuit (Does not come on) | |
| VSC OFF indicator light circuit (Remains on) | |
| VSC OFF indicator light circuit (Does not come on) | |
| Slip indicator light circuit (Remains on) | |
| Slip indicator light circuit (Does not come on) | |
| Brake hold standby indicator light circuit | |
| Brake hold operated indicator light circuit | |
Terminals Of Ecu
TERMINALS OF ECU TERMINALS OF ECU *a Component without harness connected (Skid Control ECU (Brake Actuator Assembly)) - - Terminal No. (Symbol) Terminal Description 1 (GND1) Sk ...
Dtc Check / Clear
DTC CHECK / CLEAR DTC CHECK (a) Turn the engine switch off. (b) Connect the Techstream to the DLC3. (c) Turn the engine switch on (IG). (d) Turn the Techstream on. (e) Read the DTCs following the prom ...
Other materials:
Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Front Brake: Inspection
INSPECTION PROCEDURE 1. INSPECT BRAKE CYLINDER AND PISTON (a) Check the front disc brake cylinder bore and front disc brake piston for rust and scoring. If necessary, replace the front disc brake cylinder assembly and front disc brake piston. 2. INSPECT PAD LINING THICKNESS (a) Using a ruler, mea ...
Lexus RX (RX 350L, RX450h) 2016-2025 Owners Manual > Steps to take in
an emergency: If the hybrid system will
not start
Reasons for the hybrid system not starting vary depending on the
situation.
Check the following and perform the appropriate procedure:
The hybrid system will not start even though the correct starting
procedure
is being followed.
One of the following may be the cause of the problem:
Th ...
Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual
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Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual
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