Cartek OBD2 gear indicator with 8-LED shift light

The Cartek OBD2 gear indicator with shift light displays the selected gearbox ratio and signals when the engine speed is approaching the threshold for shifting into high-gear. Its direct connection to the OBD2 port allows it to retrieve the necessary data without additional wiring.

The gear is displayed on a 7-segment digital display, with a choice of seven colors. The shift light’s 8 multicolored LEDs light up progressively according to the configured thresholds. Six light sequences and day/night brightness settings allow you to customize the display.

Technical Specifications

• Brand: Cartek
• Model: Gear Indicator OBD2
• Manufacturer Part Number: CK-LG-OBD
• Functions: current gear display and sequential shift light
• Gear indicator: 7-segment digital display, choice of 7 colors
• Number of configurable forward gears: 2 to 8
• Shift light: 8 multicolored LEDs, 6 selectable sequences
• Gear detection: calculated based on engine revs and vehicle speed, after calibration
• Connection: OBD2 connector
• Length of included cable: 1.5 m
• Settings: RPM thresholds, display color, and day/night brightness
• Operating voltage: 7 to 18 V
• Sizes listed in the product sheet: height 62 mm, width 50 mm, depth (mm) 23 mm
• Housing: PA 2200 nylon, encapsulated electronics
• Protection rating: IP64
• Operating temperature: -10 °C to +85 °C
• Storage temperature: -40 °C to +125 °C

Operation and Gear Recognition

The device uses engine revs and vehicle speed data transmitted via the OBD2 port. It calculates the selected gear based on the relationship between these values, rather than directly reading gear position information.

A learning phase is required to register each gear. After connection, the device automatically searches for the vehicle’s protocol. When the engine is turned off, it enters standby mode to reduce consumption, then reactivates when the engine is restarted.

Compatible Protocols

• SAE J1850 PWM: 41.6 kbaud.
• SAE J1850 VPW: 10.4 kbaud.
• ISO 9141-2.
• ISO 14230-4 KWP: slow or fast initialization.
• ISO 15765-4 CAN: 11- or 29-bit identifiers, at 250 or 500 kbaud.
• SAE J1939 CAN: 29-bit identifiers, at 250 kbaud.

Compatibility requires a supported protocol and the availability of engine revs and vehicle speed data.

Installation and Setup

Mount the indicator within the driver’s field of view using two M3 bolts from the bottom or the back, then connect the supplied cable to the OBD2 port. For bottom mounting, the maximum bolt depth is 8 mm.

The rear button is used to configure the display, gear learning, and shift light thresholds. These thresholds can be entered with the engine off or adjusted while the engine is running, following the Cartek procedure.

The indicator must be the only device connected to the OBD2 port. It is not compatible with OBD2 splitters and must not be connected directly to the vehicle’s electrical system.

Key Features

• Gear selection and shift light combined in a compact housing.
• OBD2 connection without additional wiring.
• Automatic protocol recognition.
• Customizable display and brightness.
• Automatic standby mode when the engine is turned off.