Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Stop Light Relay Circuit (C1A4B)
DESCRIPTION
When a stop light relay circuit malfunction signal sent from the vehicle stability control system is detected by the clearance warning ECU assembly, DTC C1A4B is stored.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| C1A4B | Stop Light Relay Circuit | Stop light relay circuit malfunction | Vehicle stability control system |
CAUTION / NOTICE / HINT
NOTICE:
-
After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.
Click here
.gif)
-
After replacing an ultrasonic sensor or the clearance warning ECU assembly, perform the necessary procedures (adjustment, calibration, initialization or registration).
Click here
-
When DTC C1A4B is stored, there may be a malfunction in the lighting system. Inspect the lighting system before performing the following procedure.
Click here
PROCEDURE
| 1. | CHECK DTC OUTPUT |
(a) Using the Techstream, check for DTCs according to the prompts on the screen.
Click here
HINT:
After turning the engine switch from off to on (IG), wait 4 seconds or more before checking for DTCs.
Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes(b) Clear the DTCs according to the screen on the Techstream.
Click here
(c) Recheck for DTCs.
Click here
HINT:
- DTC C1A4B is stored when a malfunction signal sent from the vehicle stability control system is detected.
- If the malfunctioning part has been repaired or replaced before rechecking for DTCs, DTC C1A4B will not be output again.
-
If DTC C1A4B is output frequently, duplicate the conditions that cause the problem symptoms and perform the inspection again, even though the DTC was not output when rechecking for DTCs.
Click here
| Result | Proceed to |
|---|---|
| DTC C1A4B is output | A |
| DTC C1A4B is not output | B |
| A | .gif) | GO TO PRE-COLLISION SYSTEM |
| B | | USE SIMULATION METHOD TO CHECK |
ENG / EHV Device (C1A40)
DESCRIPTION When an EFI system malfunction signal sent by the ECM is detected by the clearance warning ECU assembly, DTC C1A40 is stored. DTC No. Detection Item DTC Detection Condition Troubl ...
Brake System (C1A50)
DESCRIPTION When a vehicle stability control system malfunction signal sent from the skid control ECU assembly is detected by the clearance warning ECU assembly, DTC C1A50 is stored. DTC No. Dete ...
Other materials:
Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Sliding Roof System: Switch Failure (B2342)
DESCRIPTION This DTC is stored when the sliding roof ECU (sliding roof drive gear sub-assembly) detects that the sliding roof switch (map light assembly) is stuck for 30 seconds or more. DTC No. Detection Item DTC Detection Condition Trouble Area B2342 Switch Failure Sliding roof EC ...
Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Intelligent Clearance Sonar System: Wheel Speed Sensor Malfunction (C164D)
DESCRIPTION This DTC is stored when the clearance warning ECU assembly receives a wheel speed sensor (front speed sensor RH or front speed sensor LH, rear speed sensor RH or rear speed sensor LH) abnormality signal from the vehicle stability control system via CAN communication. DTC No. Detecti ...
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
0.01