Geely Geometry E High-Voltage Distribution System Circuit Diagnosis and Wiring Harness Replacement Guide

Fault Background

The Geometry E high-voltage distribution system uses the "high/low-voltage charging system" as its core hub: AC charging and DC charging enter from two sockets, and high voltage is then distributed from it to three high-voltage loads—the electric compressor, PTC heater, and integrated powertrain controller—with a DC bus directly connected to the traction battery. The troubleshooting approach for this system is very systematic—each circuit follows a four-step process: "DTC confirmation → visual inspection → wiring harness test → component check", and the standard values for wiring harness tests are also unified: continuity resistance less than 1Ω, voltage to body ground 0V. This article compiles the system composition, diagnostic methods for the five circuits, and high-voltage wiring harness replacement specifications into a field guide.

System Composition and Component Locations

Main connector numbers (referenced from the manual circuit diagram): AC charging socket BV24a / system side BV47a (1 line, 2 neutral, 3 ground); DC charging socket BV20a / battery side BV23a (1 HV+, 2 HV−); electric compressor side BV30a / system side BV48a; PTC controller side BV32a; integrated powertrain controller side BV50a (1 HV−, 2 HV+) / system side BV49a.

General Diagnostic Workflow

1. Obtain vehicle symptom information: Gather detailed information about the symptom from the customer and the vehicle;
2. Verify the symptom: Attempt to reproduce the symptom by simulating the customer's described scenario to identify the conditions under which it occurs;
3. Use the symptom table to troubleshoot: The symptom table covers electric compressor circuit faults, PTC heater circuit faults, and integrated powertrain controller circuit faults;
4. Inspect components via diagnostic steps;
5. Repair the faulty area: Repair or replace components;
6. Final check: Confirm the symptom no longer occurs.

Key Diagnostic Points for the Five Circuits

All circuits share the same four-step diagnostic process:

① DTC Confirmation: Confirm that with the vehicle power ON, the battery voltage is 12–14.5V → Connect the diagnostic scan tool to the DLC → With power ON, check and record DTCs, then clear them → Turn power OFF, wait 10 seconds or more, then turn ON again → Perform the circuit trigger action (AC charging / DC charging / turn on A/C to run the compressor / operate A/C switch to run PTC) → Read fault codes to confirm if they reappear. If other DTC confirmation steps were performed before this step, turn OFF and wait more than 10 seconds before starting.

② Visual Inspection: Check the wiring harness and connectors for abnormal appearance; if abnormal, repair or replace the faulty part.

③ Wiring Harness Test: With power OFF, disconnect both connectors and use a multimeter to measure each terminal according to the table—continuity resistance standard: less than 1Ω; with power ON, measure again—voltage to body ground standard: 0V; if not within standard, repair or replace the wiring harness.

④ Component Check: Inspect the component itself according to the corresponding circuit; replace if damaged.

DC Bus Replacement (Power-Down Procedure)

Removal:

1. Wear insulated protective equipment (insulated gloves, insulated shoes, face shield); turn off all electrical loads, power down the vehicle;
2. Disconnect the service disconnect switch in the direction of the arrow, then lock the service disconnect switch lock hole to prevent accidental connection and electric shock;
3. After disconnecting the service disconnect switch, wait 10 minutes to discharge capacitors before proceeding;
4. Disconnect the negative battery cable;
5. Release the connector lock, pull the handle, disconnect connector A between the DC bus and the high/low-voltage charging system (ensure the handle is fully released, pull out slowly and horizontally, insulate after disconnection); release fixing clip B;
6. After waiting 5 minutes, measure the bus voltage with a multimeter; proceed only if it is below 36V;
7. Raise the vehicle, remove the front underbody shield, traction battery anti-collision beam assembly, and engine underbody shield in sequence;
8. Disconnect connector A between the DC bus and the traction battery assembly (same procedure), release fixing clips B, C, D, and remove the DC bus.

Installation: Install in reverse order—place the bus in the correct position → connect battery-side connector A → install clips B/C/D → install engine underbody shield, traction battery anti-collision beam assembly, front underbody shield assembly → lower the vehicle → connect the high/low-voltage charging system-side connector A → install clip B → connect negative battery cable → connect the service disconnect switch. Ensure all high-voltage connectors are fully seated, following the "one insert, two clicks, three confirmations" rule.

High-Voltage Wiring Harness Replacement Key Points

• Electric compressor wiring harness: After power-down, press the first locking tab to pull out a section of the connector, then press the second locking tab to disconnect the connector from the high/low-voltage charging system; disconnect the connectors to the high-voltage heater and the electric compressor assembly in sequence, release all fixing clips, and remove; install in reverse order, all connectors follow "one insert, two clicks, three confirmations", and finally connect the DC bus and negative battery cable.
• Motor control module high-voltage wiring harness: After power-down and disconnecting the DC bus, disconnect the connector from the high/low-voltage charging system and release clips B/C/D; after raising the vehicle, remove the front underbody shield, traction battery anti-collision beam assembly, and engine underbody shield; remove the 4 star bolts securing the sealing cover, take off the cover, then remove the 2 bolts securing the harness, and remove the harness; install in reverse order, finally connect the DC bus and negative battery cable.
• Common specifications: Ensure the handle is fully released, pull out slowly and horizontally to prevent damage to connectors and harness pins; insulate high-voltage connectors immediately after disconnection.

Safety Warnings

• This article is for technical reference only; high-voltage repairs must be performed by certified personnel according to OEM specifications; readers unfamiliar with the procedures are strictly prohibited from performing operations themselves.
• The Geometry E power-down standard is the "service disconnect switch disconnection + 10-minute capacitor discharge wait + bus voltage <36V" triple defense, all indispensable; after disconnecting the service disconnect switch, the lock hole must be locked.
• High-voltage connectors must follow "one insert, two clicks, three confirmations", and insulate immediately after disconnection; do not pull the cable to disconnect the connector.
• All measurements must be performed under the specified OFF/ON states; if the battery voltage is below 12V, address the low-voltage power supply first before performing high-voltage diagnostics.

Maintenance Insights

The Geometry E high-voltage distribution system service manual turns diagnosis into a fill-in-the-blank exercise: five circuits, one template, two standard values—resistance less than 1Ω proves continuity, 0V to ground proves insulation; test the wiring harness first, then the component, and you can clearly distinguish whether the charging system or the load is faulty. Two details are most worth remembering: first, the "10-second rule" for DTC confirmation—after each code clear, you must turn OFF and wait 10 seconds before powering ON again, and you must wait again when moving between diagnostic steps; skipping this to save time can cause history codes to be mistaken for current codes. Second, the "10 minutes + 36V" double safety for power-down—after disconnecting the service disconnect switch, wait 10 minutes to discharge capacitors, and before touching the bus, measure the voltage to ensure it is below 36V; this is more rigorous than "power down and start working" and is a point where the Geometry E differs from most other models.

---

【This article is for reference only】