DTC C1A4B: Stop Light Relay Circuit [08/2013 - ]: Description
WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
The skid control ECU (brake booster with master cylinder assembly) outputs a stop light operation signal to the engine room junction block assembly. When the skid control ECU (brake booster with master cylinder assembly) detects a malfunction in the circuit related to the stop light, it informs the driving support ECU assembly via CAN communication and stores DTC C1A4B.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C1A4B | The vehicle is being driven at a speed of approximately 50 km/h (31 mph) or more and the cruise control switch (vehicle-to-vehicle distance control mode) is on. When the skid control ECU (brake booster with master cylinder assembly) detects a malfunction in the STOP light relay circuit, it sends a malfunction signal to the driving support ECU assembly via CAN communication and the driving support ECU assembly stores this DTC. |
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