CANBUS CB2OBD Speed and RPM OBDII Interface

Most modern vehicles utilise CANBUS (also known as CAN; CAN - BUS; CAN BUS; C - BUS) to transmit specific vehicle data and conditions between control modules. On OBDII-equipped vehicles, these signals are accessible directly via the OBDII diagnostic connector under the dashboard. The CB2OBD CAN Bus interface is designed to request PIDs ("On-Board Diagnostics" Parameter IDs) in the same manner as professional diagnostic tools, providing both a standard analog vehicle speed pulse signal (VSS) and an engine speed (RPM) signal for aftermarket devices[cite: 100, 101].

This interface is compatible with most vehicles fitted with an OBDII port from 2008 onwards if they follow the On-Board-Diagnostics official standard, as well as many pre-2008 models equipped with CAN Bus. Simply connect the wiring and go, no complex programming is required! Note that if a vehicle does not support PID requests via OBDII, the standard CB2 module covers alternative hardwired CAN Bus locations.

Features:

• Requests speed and RPM data via standard OBDII PID protocols for quick and non-invasive integration.
• Provides dual 12V square wave outputs for vehicle speed pulse (VSS) and engine speed (RPM).
• Ideal for navigation systems, taximeters, cruise control, telematics, car audio, and fleet management applications.
• Features dual built-in diagnostic LEDs to indicate CAN network detection, vehicle type determination, speed pulse, and RPM activity.
• Ultra-compact footprint measuring just 9 mm x 31 mm x 53 mm for discreet installation behind dash panels.

Installation Details:

• Locate the 16-pin OBDII diagnostic connector (typically located under the driver dash or kick panel).
• Connect CAN High (Yellow wire) to OBDII Pin 6 and CAN Low (Blue wire) to OBDII Pin 14 using insulated solder joints. Do not cut factory wires.
• Connect chassis ground (Black wire) to a clean earth point, and power (Red wire) to a +12V regulated ignition-controlled supply via a 1A inline fuse. (Do not power directly from constant OBDII power, as an ignition-switched line ensures the module shuts down and prevents battery drain when the vehicle is off).
• Mount the interface close to the connector. Do not extend the CAN High and CAN Low wires.
• If extending the Orange speed output wire or Green RPM output wire, route them away from high-current electrical noise sources such as ignition components or heater fan motors.
• Diagnostic LED sequence: Upon power-up, both LEDs light up. The GREEN LED remains on while listening for CAN data. Once CAN Bus traffic is detected, the RED LED turns on. When driving, the RED LED pulses relative to vehicle speed and the GREEN LED flashes relative to engine RPM.
• Disconnect the CAN interface prior to connecting any diagnostic scan tools to the OBDII port to avoid diagnostic conflicts.

Connections:

Specifications:

• Frequency output (Speed): Approximately 0.62 Hz per every 1 kph (1 Hz per every 1 mph)
• Frequency output (RPM): 2 pulses per revolution
• Minimum speed: Approximately 3 kph (1.7 mph)
• Approximate pulses per km: 2236 (per mile: 3600)
• Output signal: 12V square wave
• Supply voltage: 12V DC (ignition controlled supply)
• Current draw: Approximately 30 mA
• Dimensions: 9 mm x 31 mm x 53 mm
• Warranty: 12 months

Important Notes:

All connection information is provided for guidance only and to the best of our knowledge. Vehicle manufacturers may vary wire colours or OBDII pin assignments between models and production years. Always verify wiring with a vehicle schematic before installation. Note that the presence of an OBDII port does not guarantee that vehicle speed or RPM PID data is broadcast across the diagnostic CAN lines. If speed and RPM data are unavailable at the OBDII socket, a hardwired CAN interface (such as model CB2) connected to the vehicle engine or body CAN network should be used instead.