Inspection Methods
For the inspection of ESP system,if the fault light illuminates,use the decoder to read the fault code and operate according to the instructions of the fault code.
1)Wheel Speed Sensor Inspection
Combined with the structure and working principle of electromagnetic wheel speed sensor,use the following method to make quick judgment:
(1)(Dismantle the connector),adjust the digital universal meter to resistance range,and measure the resistance of sensor’s pin 1 and 2.The standard value is 1.0～1.3 kΩ.Otherwise,the sensor is burned down.
(2)Disconnect the ESP control module wire harness connector,and check the wire harness resistance between wheel speed sensor and ESP control unit.The standard value is below 5Ω,otherwise,the wire harness is open circuit.
(3)Measure the resistance between wheel speed sensor wire harness connector terminal 1 and reliable grounding and the resistance between terminal 2 and reliable grounding.The standard value is above 10 MΩor even higher.Otherwise,replace the wire harness.
Besides,check whether the tooth ring of wheel speed sensor is deformed or not,whether there is tooth missing or whether the bearing clearance is normal or not.(https://www.daowen.com)
2)Inspection of ESP Control Unit
Fig.5.10 Terminals of ESP Control Unit
(1)For the inspection of power source circuit,the voltage of the storage battery should keep above 12 V.Check three power source line,and the voltages between ESP control unit terminal 1,2,25 respectively and reliable grounding.The standard voltage is the storage battery’s voltage,otherwise,there exists open circuit and fuse failure in the wire harness between terminal 1,2 and 25 and the storage battery.
(2)For the inspection of grounding,when the power is cut off,check the resistance between terminal 13 and the grounding.The standard value is below 5 Ω,otherwise,you need to check whether the grounding line is open circuit or not.
(3)Please refer to Chapter 2 CAN-BUS System for the inspection of CAN wire.