How to detect Auto GND badness?

01 starter operation, if the battery grounding wire temperature is too high, even at the end of the phenomenon of red on the ground, indicating that the battery grounding wire contact bad.X431 Tool

02 in the case of non-charged measurement of the resistance value of the ground point, that is, with a multimeter of a table pen reliably connected to the wire, Yanhua Digimaster 3 another pen and metal parts of the body connected to measure the resistance between them, if there is resistance, The VXSCAN EL-50588

03 using simulated vibration method. For the suspected parts, you can in the vertical direction and horizontal direction gently shaking the line, to simulate the state of TOYO KEY OBD II vibration when driving the car, while observing the reaction of the relevant parts to determine whether the ground with Weld, loose, poor contact or wire break phenomenon.Autel MS906  If you shake a ground line when the fault reproduction or failure disappeared, indicating that the bad place where the ground here.

04 When the circuit is energized, the voltage drop of the tapping point is measured with a multimeter. The reading should be as low as possible (close to 0). The method is to start the engine,Xhorse Condor XC-002 the use of multimeter DC voltage block, the red pen touch the generator output, black pen touch the engine body, measured a voltage value; and then the red pen touch the output of the generator, black pen contact The metal part of the frame, and then measured a voltage value. Under normal circumstances, these two voltage values ​​should be consistent. If the Autel MS908P former value is large, the latter value is small, a difference of 0.5V or more, indicating the existence of more than 0.5V voltage drop, it is by the engine body and the frame caused by bad grounding.

Detection of a point of the situation, it should be measured at the point of the power supply voltage, try not to measure the point of the negative resistance of the power supply, this is because the multimeter itself has a certain internal resistance, measured the resistance value of the larger error.