Lexus ES: Stop Light Relay Circuit (C1A4B)
DESCRIPTION
When a stop light relay circuit malfunction signal sent from the electronically controlled brake 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 | Electronically controlled brake system |
CAUTION / NOTICE / HINT
NOTICE:
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After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.
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After replacing an ultrasonic sensor or the clearance warning ECU assembly, perform the necessary procedures (adjustment, calibration, initialization or registration).
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When DTC C1A4B is stored, there may be a malfunction in the lighting system. Inspect the lighting system before performing the following procedure.
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PROCEDURE
| 1. | CHECK DTC OUTPUT |
(a) Using the Techstream, check for DTCs according to the prompts on the screen.
HINT:
After turning the power 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.
Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs(c) Recheck for DTCs.
Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble CodesHINT:
- DTC C1A4B is stored when a malfunction signal sent from the electronically controlled brake system is detected.
- If the malfunctioning part has been repaired or replaced before rechecking for DTCs, DTC C1A4B will not be output again.
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If DTC C1A4B is output frequently, duplicate the conditions that cause the problem symptoms and perform troubleshooting again, even though the DTC was not output when rechecking for DTCs.
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| 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 |
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DESCRIPTION When a SFI system malfunction signal sent by the hybrid vehicle control ECU is detected by the clearance warning ECU assembly, DTC C1A40 is stored. DTC No. Detection Item DTC Detect
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DESCRIPTION When a SFI system malfunction signal sent by the hybrid vehicle control ECU is detected by the clearance warning ECU assembly, DTC C1A40 is stored. DTC No. Detection Item DTC Detect
Brake System (C1A50)
DESCRIPTION When an electronically controlled brake system malfunction signal sent from the skid control ECU is detected by the clearance warning ECU assembly, DTC C1A50 is stored. DTC No. Detect
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Problem Symptoms Table
PROBLEM SYMPTOMS TABLE HINT:
If CAN communication system and lane control system DTCs are not output and any of the following problem symptoms exist, perform troubleshooting by checking the appropriate suspected areas in the order they are listed.
Use the table below to help determine the cause
Freeze Frame Data
FREEZE FRAME DATA DESCRIPTION (a) Whenever a road sign assist system DTC is stored, the forward recognition camera stores the current vehicle state (ECU and sensor information) as Freeze Frame Data. CHECK FREEZE FRAME DATA (a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c
