Reference
Network explorer
Reading the module, bus and pin map.
Network Explorer is a map of the CMA car's control units and connections. Use it to see which systems share a network and where a control unit sits. The map is a reference for understanding the car; it does not show a live wiring test.
What the map contains#
The interactive map is a built-in reference diagram of the CMA platform rather than a live reading from your car. It includes:
- 170 electrical units: Control modules, sensors, switches, actuators, and fuse/power boxes.
- 295 connections across nine networks: Showing how data and power travel between units.
- 622 documented connector pin rows: Listing pin numbers, signal names, and wire colours.
- 170 reference bus message routes: Illustrating how common signals travel between modules.
While Hanterill's live diagnostic screens talk to modules by their logical network addresses, the Network Explorer organizes the car by physical hardware positions, wiring harnesses, and connector numbers. You can use both views side by side when troubleshooting a communication or wiring fault.
Move around the canvas#
The map groups components into functional clusters across the vehicle:
- Drivetrain and high-voltage energy
- Chassis, steering, and braking
- Driver assistance (ADAS) and active safety
- Body, doors, seats, and cabin comfort
- Driver controls and steering column switches
- Displays, sound, and infotainment
- Connectivity and diagnostic gateway
- Core central computers
- Power distribution and ground points
- Peripheral sensors, switches, and actuators
Three tools at the top of the explorer help you find what you need quickly:
- Bus filter
- Toggle each of the nine networks on or off. Power (12 V / ground) and discrete signal wires are turned off by default so they do not clutter the data buses.
- Search
- Find any unit name, module abbreviation, connector code, signal name, or pin number. Open search anytime with Ctrl+K or Cmd+K.
- Path trace
- Pick any two units on the map to highlight the shortest wiring and gateway path connecting them.
Clicking any unit opens its detail drawer with its hardware location in the vehicle, its connected buses, and its connector pin-out table.
The nine vehicle networks#
Each network type is drawn with its own colour and line style so you can isolate one system at a time:
- CAN
- The main control buses for body, chassis, drivetrain, and diagnostics across eleven named segments (most running at 500 kbps).
- LIN
- Thirteen low-speed local single-wire buses connecting door switches, seat motors, climate flaps, and rain/light sensors to their parent modules.
- FlexRay
- A high-speed, time-synchronized backbone linking the central computers, gateway, driver assistance, and chassis controllers.
- MOST
- The high-bandwidth digital audio and media ring connecting infotainment and amplifier modules.
- Video / LVDS
- Dedicated high-speed coaxial video links for the 360-degree parking cameras, forward camera, and dashboard displays.
- Ethernet
- The high-speed diagnostic link between the OBD-II port and the Vehicle Gateway Module.
- 400 V HV
- High-voltage orange traction cables linking the battery pack, onboard charger, DC fast-charge port, air-conditioning compressor, heaters, and drive inverters.
- 12 V / GND
- Low-voltage power supply and chassis ground distribution (hidden by default).
- Discrete I/O
- Direct point-to-point sensor and switch wires (hidden by default).
How diagnostic traffic enters the network#
When you plug an Ethernet diagnostic cable into the OBD-II port, your laptop talks directly to the Vehicle Gateway Module (VGM) over the OBD Ethernet link. From there, the gateway and the Central Electronic Module (CEM) route your diagnostic requests onto the internal FlexRay, CAN, and LIN buses to reach the rest of the vehicle.
- CEM (4/56)
- Central Electronic Module. Manages body functions, security, and power states while bridging the FlexRay backbone to multiple CAN and LIN segments.
- VGM (4/314)
- Vehicle Gateway Module. Terminates the OBD-II Ethernet connection and routes diagnostic and infotainment traffic across the car's internal buses.
When you use Path trace to follow a signal from a door or climate sensor to a drivetrain or dashboard module, you will almost always see the route pass through either the VGM or the CEM.
Why the wiring map and the ECU Registry have different counts#
The Network Explorer and the ECU reference look at the vehicle from two different angles:
- Network Explorer (170 physical units): Includes every physical box on the wiring diagram, including fuse boxes, simple switches, cameras, and LIN sub-sensors that do not have their own independent diagnostic address.
- CMA ECU Registry (49 diagnostic modules): Lists the primary control units that answer diagnostic requests directly through the gateway (44 active modules on a battery-electric car, plus 5 reference entries reserved for hybrid, combustion, or air-suspension variants).
Why the ECM label appears on electric models
On the reference wiring diagram, the propulsion controller position carries the traditional label "Engine Control Module (ECM)". On a battery-electric CMA car, that position acts as a drive-unit and inverter controller rather than a combustion engine computer.
Confirmed pin-outs versus block-diagram links#
On the map canvas:
- Solid lines represent connections with documented connector pin numbers, signal names, and wire colours.
- Dashed lines represent connections where two modules are known to communicate on a shared bus, even when the individual connector pin number is not listed in the table.
Clicking any pin row in the detail drawer lets you jump directly to the module at the other end of that wire.
Next#
- ECU reference: the diagnostic control units Hanterill talks to directly.
- Protocols (DoIP, UDS and CAN): how diagnostic messages travel across Ethernet and CAN.
- Connection: what cables and adapters you need to connect to the car.
- Supported vehicles: platform support across CMA, SPA, and SEA1.