Neta V New Energy Electronic Control Component Diagnosis and Disassembly Guide

Fault Background

For the Neta V, there are two "structural red lines" that must be remembered when repairing new energy electronic control components: First, the drive motor high-voltage wiring harness and the drive motor controller are integrated and cannot be replaced separately—if the harness is damaged, the entire controller assembly must be handled; Second, the motor controller ground wire fixing bolt is M8, torque 15±2.5N·m. On the diagnostic side, the four major DTC tables are clearly divided: BMS table (U007488 internal master-slave CAN fault, U007687 vehicle CAN wire open circuit/poor contact, P1B4F00 VCU communication timeout, P1B2200 collision alarm), OBC table (P1D0200 output overvoltage shutdown, P1D0300 internal serial port fault, U011187 BMS communication fault including "OBC not awakened"), DCDC and VCU tables. The disassembly sequence is unified: disconnect battery negative terminal → drain coolant → (for MCU, also recover refrigerant) → disconnect all connectors → remove ground wire and fixing bolts. This article compiles the four major DTC tables, MCU/OBC/high-voltage cable disassembly, and safety discipline into a reference guide.

Safety Discipline (Applicable to All Chapters)

• During maintenance and repair, use insulated professional tools, and wear insulated gloves and insulated shoes; do not wear gold, silver jewelry, watches, or other metal accessories during operation and maintenance; it is strictly forbidden to operate bare-handed without protective equipment;
• Battery system and high-voltage system maintenance must be performed by professional technicians with battery expertise, an electrician's certificate, and authorization from our company's technical training;
• Before disassembling high-voltage systems, prepare the required insulated tools; when disassembling chassis components, confirm that the lift safety lock is engaged; welding or modifying suspension load-bearing and guide components is prohibited.

DTC Table Key Points

BMS: U007488 (BMS internal master-slave communication CAN_H/CAN_L fault); U007687 (BMS vehicle CAN wire open circuit or connector poor contact / vehicle CAN bus fault); Fast charge CAN Bus Off fault; P1B4F00 (VCU communication timeout, CAN wire fault); U02088 (communication timeout); P1B2200 (collision alarm, ACU reports collision fault).

OBC: U007388 (CAN bus CANH-GND fault); U011187 (BMS communication fault: vehicle message abnormal / OBC communication circuit fault / OBC not awakened); P1D0200 (charger output overvoltage shutdown: battery voltage abnormal / OBC fault / abnormal connection from OBC output to battery / OBC damaged); P1D0300 (charger internal serial port fault: OBC software/hardware mismatch).

DCDC / VCU: Troubleshoot according to their respective DTC tables (DCDC and VCU tables are included in the same chapter).

Disassembly Key Points

Motor Controller (MCU) Removal: Disconnect battery negative cable → drain coolant → recover refrigerant → remove charger assembly (OBC) and bracket → disconnect motor controller inlet pipe A and drive motor connector B → remove motor controller ground wire fixing bolt A (M8, torque 15±2.5N·m) and disconnect ground wire B → remove motor controller housing fixing screws and take out MCU.

Charger Assembly (OBC) and Bracket: Disconnect negative terminal → drain coolant → disconnect connector A to drive motor controller wiring harness → disconnect connector B to air conditioning cable assembly → disconnect connector C to battery pack slow charge input wire → disconnect low-voltage harness connector → remove front compartment harness ground wire fixing bolt and detach ground wire → remove fixing parts and take out assembly.

Battery Pack to Motor Controller Cable Assembly: Disconnect negative terminal → remove charger and bracket assembly → disconnect harness connector from battery pack assembly to motor controller → remove along the path. Note: The drive motor high-voltage wiring harness and the drive motor controller are integrated and cannot be replaced separately.

Slow Charge Port and Harness Assembly: Remove according to the electrical system chapter, ensuring each connector is matched one-to-one.

Safety Warnings

• This article is for technical reference only. High-voltage system maintenance must be performed by qualified professional technicians (with battery expertise + electrician's certificate + company training authorization) according to OEM specifications. Readers who are not familiar with these procedures are strictly prohibited from operating on their own.
• Before high-voltage work: disconnect battery negative terminal → drain coolant (for MCU, also recover refrigerant), the sequence must not be reversed.
• Use insulated tools, insulated gloves, and insulated shoes throughout; remove metal accessories; engage lift safety lock.
• The drive motor high-voltage wiring harness and the controller are integrated; it is prohibited to replace or disassemble the harness separately.
• Ground wire bolt M8 must be tightened to 15±2.5N·m; too loose or too tight may cause high-voltage circuit faults.

Maintenance Insights

The biggest reminder from the Neta V manual is the "integrated component thinking"—the drive motor high-voltage wiring harness and the motor controller are integrated and cannot be replaced separately, meaning that "harness insulation damage" on this vehicle is not a harness replacement task, but a judgment issue for the entire assembly. On the diagnostic side, remember two OBC keywords: P1D0200 output overvoltage shutdown (first check battery voltage abnormality and the connection from output to battery, then suspect the OBC itself) and "OBC not awakened" in U011187 (for communication faults, don't just check the wiring; the wake-up condition is the third root cause). The BMS table is a collection of CAN faults—U007488 master-slave CAN, U007687 vehicle CAN open circuit/poor contact, all are "measure the wires first, then replace the board". On the disassembly side, one set of numbers: MCU ground wire M8 bolt 15±2.5N·m; on the process side, one main line: disconnect negative terminal → drain coolant → (for MCU, recover refrigerant) → disconnect connectors → remove ground wire—the Neta V's MCU simultaneously uses liquid cooling and refrigerant circuits, which is its difference from most pure electric vehicles.

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【This article is for reference only】