1、Relay adhesion fault Relay function description
The contactor is a high-voltage on-off switching component. Its main function is to control the connection and disconnection of the charging and discharging circuits, control the output and disconnection of the high-voltage power of the Pack, control the charging process, control the opening and closing of the thermal management system, and has the function of disconnecting all high-voltage connection circuits in the event of a battery self-protection fault or fire warning fault to protect the safety of the battery and the entire vehicle.
1.1: Connect the debug harness and the host computer.
1.2: Power on the vehicle and check for a fault code indicating a stuck relay.
1.3: Remove the high-voltage box (junction box) from the vehicle and open the top cover. If a stuck main relay fault is reported, proceed to the next step. For any relay other than the main relay, proceed to step 5.
1.4: Disconnect the high-voltage wiring harnesses before and after the pre-charge relay.
1.5: Use a multimeter to measure the resistance between the relay's DC+ and DC- terminals (normally, this should be infinite). If not, proceed to the next step. If normal, proceed to step 7.
1.6: If the heater relay is stuck, check the insulation and resistance of the heater circuit. If normal, replace the relay. If not, repair or replace it. Ensure the circuit is functioning properly before replacing the relay.
Heating Module Operating Principle: When the heating start conditions are met, the BMS controls the heater relay to close, energizing the heating circuit and turning on the heating. Heating film fault diagnosis conditions: If the minimum average temperature rise of any CSC is ≤3°C for three consecutive times during continuous heating for 40 minutes,
2.1: Power on the vehicle and check the fault code for a heating circuit fault or heating film fault. Verify that the heating wiring harness is correctly connected according to the electrical schematic.
2.2: Power off the vehicle, disconnect the high-voltage MSD, disconnect the positive and negative connectors of the high-voltage heating, and measure the resistance of the heating film with a multimeter.
2.3: Locate the abnormal resistance branch, confirm the fault point in the heating circuit or the abnormal resistance electrical box, and repair it.
2.4: Check the heating wiring harness for open circuits or poor contact.
Charging gun CC2 is 1K ohm to ground. Charging base CC1 is 1K ohm to ground.
Charging base PE is continuous to ground. 120 ohm between S+ and S-.