When the vehicle is turning with respect to a vertical axis the yaw rate sensor detects the yaw rate electroniclly by the vibration change of plate fork inside the yaw rate sensor. If yaw velocity reaches the specific velocity after it detects the vehicle’ yawing, the ESP control is reactivated. The later G sensor senses vehicle’s lateral G. A small element inside the sensor is attached to a deflectable leverarm by later G. Direction and magnitude of lateral G loaded to vehicle can be known with electrostatic capacity changing according to lateral G. The output voltage of the lateral G sensor is 2.5V when the vehicle is at a standstill. Only with lateral G sensor, the ESP can not be reactivated.
A failure is detected if the lateral acceleration sensor or yaw rate sensor signal stays in the fault range longer than the specified failure detection time. The Monitoring starts 1sec after Power Up.
Item | Detecting Condition | Possible cause | |
Case1 | DTC Strategy | ● Lateral G sensor monitoring | ● Faulty Yaw Rate & Lateral G sensor ● Open or short of Yaw Rate & Lateral G sensor ● Faulty HECU |
Detect Mode | ● Initial Check ● Outside the ABS control cycle ● Inside the ABS control cycle ● Diagnosis mode ● Failure mode | ||
Enable Conditions | ● When VLG >4.90±0.05V or VLG <0.10±0.05V continue 1sec, - The monitoring starts 1sec after power up. | ||
Case2 | DTC Strategy | ● YAW rate Sensor monitoring | |
Detect Mode | ● Initial Check ● Outside the ABS control cycle ● Inside the ABS control cycle ● Diagnosis mode ● Failure mode | ||
Enable Conditions | ● When VYAW > 4.90±0.05V or VYAW < 0.10±0.05V continue 1sec, - The monitoring starts 1sec after power up. | ||
Case3 | DTC Strategy | ● CBIT(Commended built in test) monitoring | |
Detect Mode | ● Initial Check | ||
Enable Conditions | ● When CBIT is high ( >3.6V ),YAW signal voltage don’t increase 0.1~1.2V than case of low state of CBIT pin . ● Lateral G signal voltage is smaller than 4.1±0.1V when CBIT is high( >3.6V ) . ● When GND of yaw rate sensor and lateral G sensor are open. | ||
Fail Safe | ● Inhibit the ESP control and allow the ABS/EBD/TCS control. Meanwhile, stop checking the ESP switch failure under the ESP control. ● The ESP warning lamps are activated. |
