Next, the voltage between the vehicle's slow-charging CC terminal and the PE terminal was measured, which was about 12 V (normally it should be around 6 V), indicating the voltage is too low. At this point, it was basically suspected that there was a short circuit between the vehicle's slow-charging interface terminals CC and CP. Using a multimeter in buzzer mode to measure, it was found that the vehicle's slow-charging interface terminals CC and CP were conductive. By carefully inspecting the low-voltage signal harness between the vehicle's slow-charging interface and the onboard charger, it was finally found that a copper wire inside the connector of the onboard charger's low-voltage signal cable shorted terminal 3 (CP terminal) and terminal 4 (CC terminal) together. It was inferred that the fault was caused by this.

Troubleshooting: After cleaning the copper strands inside the low-voltage signal wire connector of the charger, test the vehicle. The vehicle's charging returned to normal, and the fault was cleared.