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 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.
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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 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.
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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Precaution
PRECAUTION CHARGING SYSTEM PRECAUTION CAUTION:
Orange wire harnesses and connectors indicate high-voltage circuits. To prevent electric shock, always follow the procedure described in the repair manual. Click here
To prevent electric shock, wear insulated gloves when working on wire harnesse
Terminals Of Ecu
TERMINALS OF ECU HINT: Check from the rear of the connector while it is connected to the components. DCM (TELEMATICS TRANSCEIVER) Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition G128-1 (+B) - G128-20 (E) GR - W-B Power source (+B) Power swi
