DESCRIPTION
The skid control ECU (brake actuator assembly) sends a stop light operation request
signal to the stop light relay (stop light switch assembly). If the skid control
ECU (brake actuator assembly) detects a malfunction in the stop light relay circuit,
the millimeter wave radar sensor assembly stores DTC C1A4B.
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DTC No.
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Detection Item
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DTC Detection Condition
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Trouble Area
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C1A4B
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Stop Light Relay Circuit
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While the ignition switch is ON, the millimeter wave radar sensor assembly
receives a stop light relay circuit malfunction signal from the skid control
ECU (brake actuator assembly) for 1 second or more.
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- Vehicle stability control system
- Millimeter wave radar sensor assembly
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CAUTION / NOTICE / HINT
NOTICE:
- When replacing the millimeter wave radar sensor assembly, always replace
it with a new one. If a millimeter wave radar sensor assembly which was installed
to another vehicle is used, the information stored in the millimeter wave radar
sensor assembly will not match the information from the vehicle. As a result,
a DTC may be stored.
- If the millimeter wave radar sensor assembly has been replaced, be sure
to perform millimeter wave radar sensor assembly adjustment.
Click here 
- The pre-collision system uses the CAN communication system. First, confirm
that there are no malfunctions in the CAN communication system. Refer to How
to Proceed with Troubleshooting.
Click here
PROCEDURE
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1.
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CHECK FOR DTCs (VEHICLE STABILITY CONTROL SYSTEM)
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HINT:
Pre-collision system DTC C1A4B may be stored due to a malfunction in the vehicle
stability control system. Therefore, it is necessary to check for and troubleshoot
vehicle stability control system DTCs first.
(a) Check for DTCs.
Click here
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Result
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Proceed to
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Vehicle stability control system DTCs are not output
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A
|
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Vehicle stability control system DTCs are output
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B
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| B |
 |
GO TO VEHICLE STABILITY CONTROL SYSTEM
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| A |
|
|
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2.
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CHECK FOR DTCs (PRE-COLLISION SYSTEM)
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(a) Clear the DTCs.
Click here
(b) Make sure that the DTC detection conditions are met.
HINT:
If the detection conditions are not met, the system cannot detect the malfunction.
(c) Check for DTCs.
Click here
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Result
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Proceed to
|
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DTC C1A4B is not output
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A
|
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DTC C1A4B is output
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B
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| A |
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USE SIMULATION METHOD TO CHECK
|
| B |
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REPLACE MILLIMETER WAVE RADAR SENSOR ASSEMBLY
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