ECU Modules

The CarCoding scan map holds 3175 module definitions across 39 make groups and 33 module types. The numbers are definition counts in the map.

By module type

• Seat Module177 definitions The seat module controls the electric adjustment motors, memory positions and, where fitted, heating and ventilation. The connectors under the seat are frequently disturbed points.
• High-Voltage System Modules153 definitions This heading covers the high-voltage side of electric and hybrid vehicles: DC-DC converter, inverter, power distribution and safety monitoring units. High-voltage systems are not open to unauthorised intervention; this page only describes what the modules are and how they appear in the address map.
• Body Control Module126 definitions The body control module runs locking, windows, wipers, interior lighting and similar comfort functions; most of these are spread across several interconnected modules rather than one box. Supply and ground quality are unusually decisive on this side.
• Door Module121 definitions Door modules locally control the window, mirror, lock and door lighting and talk to the body module. Because the harness passes through the door hinge, wiring fatigue is common in this area.
• Steering Module119 definitions The electric power steering module reads steering angle and torque sensors and drives the assist motor. The angle sensor may require calibration after a battery change or suspension work.
• Climate Control Module117 definitions The climate module manages cabin temperature, air distribution flaps and compressor demand. Flap motors report position feedback, so mechanical binding is a common fault source here.
• Transmission Control Unit117 definitions The transmission control unit executes gear changes through solenoids that manage hydraulic pressure, and monitors input/output speed sensors and fluid temperature. It exchanges data with the engine module continuously.
• High-Voltage Battery Module106 definitions The battery management system monitors cell voltages, temperatures and current, sets charge and discharge limits and performs cell balancing. On electric vehicles it is one of the largest module families in the map.
• Lighting Module97 definitions The lighting module drives exterior lighting and monitors lamp circuit current. With LED and matrix headlights each segment is driven separately, so this module carries more codes than a conventional bulb system.
• Airbag / SRS Module95 definitions The SRS module monitors the firing circuits of the airbags and belt pretensioners, the crash sensors and the belt switches. Circuit resistances must stay inside a narrow window; a value outside it is stored as a code. safety-critical
• Audio / Multimedia Module94 definitions The audio and multimedia module drives the speakers, the amplifier and the media sources. It usually sits on a separate comfort bus.
• Engine Control Unit90 definitions The engine control unit manages fuel injection, ignition timing and air measurement; most emissions-related monitoring also runs here. The mandatory OBD-II emissions channel points at this module, which is why it is usually the easiest one to reach with a generic adapter.
• Sensor Modules84 definitions This heading collects sensor units that join the network with their own identity: intelligent battery sensors, rain/light sensors and similar. Unlike a simple sensor, they publish their measurement as a network message.
• Telematics Module78 definitions The telematics module handles the vehicle’s mobile network connection and emergency call function. With its own power supply and antenna it behaves as a separate node on the network.
• Driver Assist and Safety Modules77 definitions This heading collects a mixed set of safety hardware such as blind spot radars, corner radars and belt pretensioner units. Because the set is mixed, it does not map one-to-one onto a single fault code category.
• Charger Module75 definitions The on-board charger converts alternating current from the grid into the direct current the battery needs and handles communication with the charging station.
• Camera Module70 definitions Camera modules provide rear view, surround view and forward camera functions. The forward camera also processes images for lane and traffic sign recognition; calibration may be required after a windscreen change.
• Instrument Cluster67 definitions The instrument cluster drives speed, rpm, temperature and warning lamps; it measures few of these itself and instead receives them from other modules over the network. A warning shown on the cluster therefore usually originates in another module.
• ABS / ESP Module58 definitions The ABS and electronic stability control module reads four wheel speed sensors and modulates brake pressure per wheel through valves in the hydraulic unit. It receives steering angle and yaw data over the network. safety-critical
• Brake Control Module56 definitions The brake control module handles additional braking functions such as the electric parking brake, brake boosting and regenerative braking. It can exist as a separate box alongside the ABS module. safety-critical
• Adaptive Cruise Control Module52 definitions The adaptive cruise module measures the distance and speed of the vehicle ahead using radar or lidar, then requests acceleration or deceleration from the engine and brake modules. Radar alignment is mechanically sensitive.
• Immobiliser / Alarm Module52 definitions The immobiliser and alarm module handles key recognition, motion sensors and door/bonnet switches. This page only describes what the module is and how it is defined in the address map.
• Gateway Module51 definitions The gateway module bridges the vehicle’s different data buses and decides which message crosses to which bus. Diagnostic traffic passes through it as well, so a problem in the gateway can make every individual module look unreachable.
• AWD / Transfer Case Module50 definitions The all-wheel-drive module distributes torque to the axles through a clutch or transfer case. It depends on ABS data because it monitors wheel speed differences.
• Suspension Module47 definitions The suspension module manages ride height, damping stiffness or air suspension pressure. Height sensors and compressor circuits are connected to it.
• Park Assist Module36 definitions The park assist module reads the ultrasonic sensors and produces distance warnings; on vehicles with automated parking it works together with the steering module.
• Roof Module27 definitions The roof module operates the sunroof, panoramic glass or convertible roof mechanism. Because end positions have to be learned, it may require re-initialisation after a battery disconnection.
• Tyre Pressure (TPMS) Module23 definitions The tyre pressure monitoring module reads radio signals from in-wheel sensors, or infers pressure loss indirectly from ABS wheel speeds. Sensor matching may be required after a tyre change.
• Navigation Module18 definitions The navigation module holds position data and map software; it receives vehicle speed and heading over the network.
• Tailgate Module16 definitions The powered tailgate module controls the open/close motor, anti-pinch detection and the latch mechanism.
• Junction Box Module10 definitions A smart junction box replaces conventional fuses and relays with semiconductor switches and measures the current of each output. Since power distribution happens here, a problem in this module can affect many seemingly unrelated modules at once.
• Lane Assist Module9 definitions The lane assist module extracts lane markings from the camera image and, where needed, requests a correction from the steering module.
• Trailer Module8 definitions The trailer module drives the lighting and brake signals at the towbar socket and informs other modules when a trailer is attached.

ECU maps by make

Every make has its own module naming and address layout. The make pages list the modules defined in the map for that make.

ECU maps by make →

• Audi715 module definitions
• Volkswagen715 module definitions
• Renault215 module definitions
• FCA136 module definitions
• PSA129 module definitions
• Toyota127 module definitions
• Nissan108 module definitions
• Volvo101 module definitions
• Fiat85 module definitions
• BYD80 module definitions
• Jaguar Land Rover78 module definitions
• Ford58 module definitions

Looking for what a fault code means? Fault code library.

Data source: the CarCoding ECU scan map (ecuDatabase.ts). The addresses and names in the table are definitions from the map; they can differ depending on the hardware and software version in your vehicle.