Lexus RX (RX 350L, RX450h) 2016-2025 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) 2016-2025 Repair Manual > Sfi System: High Pressure Fuel Pump Circuit Open (P123513)
DESCRIPTION The high-pressure direct injection fuel system consists of a spill control valve, check valve, fuel relief valve, fuel pressure sensor, fuel pump assembly (for high pressure side) and fuel injector assemblies (for direct injection). The spill control valve adjusts the return volume of th ...
Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Dynamic Radar Cruise Control System: Software Incompatibility with Brake System Control Module Invalid/Incompatible Software Component (U031857)
DESCRIPTION If the vehicle information stored in the forward recognition camera does not match the vehicle information sent from the skid control ECU (brake actuator assembly), the forward recognition camera stores DTC U031857. DTC No. Detection Item DTC Detection Condition Trouble Area M ...
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
0.0088