Geloo A401 HUD
Geloo Car HUD Head Up Display User Manual
Model: A401 HUD
1. Introduction
Thank you for choosing the Geloo Car HUD Head Up Display. This device is designed to enhance your driving experience by projecting essential vehicle data directly into your line of sight. Featuring a dual OBD2 and GPS system, it offers comprehensive monitoring capabilities for a wide range of vehicles. Please read this manual thoroughly before installation and operation to ensure proper use and optimal performance.
2. Product Overview
The Geloo Car HUD Head Up Display is a versatile automotive accessory that provides real-time driving information. Its 240x240 resolution screen ensures clear visibility of data. The unit features a 270-degree rotatable screen, allowing for flexible installation on either the car's A-pillar or dashboard. It supports both OBD2 and GPS working systems, making it compatible with various vehicle types including cars, buses, and trucks.

Figure 2.1: Geloo Car HUD Head Up Display in use, showing speed, RPM, time, and temperature.
3. Key Features
- OBD2+GPS Dual System: Offers two operating modes for broad vehicle compatibility. OBD mode is suitable for most vehicles manufactured after 2012. GPS mode is universally compatible with all vehicles.
- Superior Quality Display: Features a 240x240 resolution screen for clear display of rich driving data.
- Flexible Installation: 270-degree rotatable screen supports installation on car A-pillar or dashboard.
- Comprehensive OBD2 Data: Displays Speed, Clock, RPM, Water Temperature, Voltage, Fuel Consumption, Driving Time, Driving Distance, Turbo Pressure, Acceleration Test, Brake Test, Clear Fault Code, and Oil Temperature.
- Essential GPS Data: Displays Speed, Clock, Driving Time, Satellite Number, Altitude, Driving Distance, and Compass.
- Integrated GPS Functionality: GPS data can be displayed simultaneously in OBD mode.
- Easy Plug and Play Installation: Simple connection to the power supply. Compatible with vehicles with a voltage range of 8-18V.
4. Package Contents
Upon opening the package, please verify that all the following items are included:
- 1x Geloo Head Up Display Unit
- 1x OBD2 Cable
- 1x User Manual
- 1x Adhesive Tape
- 1x Hexagon Wrench
- 1x Crowbar

Figure 4.1: All components included in the Geloo HUD package.
5. Installation
The Geloo HUD is designed for easy installation with two primary placement options:
- Dashboard Installation: Place the HUD unit directly on your vehicle's dashboard. Use the provided adhesive tape to secure it firmly in place, ensuring it does not obstruct your view or interfere with driving controls.
- A-Pillar Trim Installation: The rotatable screen allows for mounting on the A-pillar trim. Secure the unit using the provided tape or other suitable mounting methods, ensuring stability.
After positioning the unit, connect the OBD2 cable to your vehicle's OBD2 port, typically located under the dashboard near the steering wheel. Ensure the connection is secure. The device is plug-and-play and will power on automatically once connected to the vehicle's power supply.


Figure 5.1: Installation options: A-pillar (left) and dashboard (right).
6. Operation
The Geloo HUD operates with a dual OBD2 and GPS system, offering various display modes and settings.
6.1. System Modes

Figure 6.1: Overview of OBD and GPS data points.
- OBD2 Mode: This is the default mode. It reads data directly from your vehicle's On-Board Diagnostics system. Data includes Speed, Clock, RPM, Water Temperature, Voltage, Fuel Consumption, Driving Time, Driving Distance, Turbo Pressure, Acceleration Test, Brake Test, Clear Fault Code, and Oil Temperature. Note: OBD mode is primarily compatible with vehicles manufactured after 2012.
- GPS Mode: If your vehicle is not compatible with OBD2 mode, or if you prefer GPS data, the device can be switched to GPS mode. This mode provides Speed, Clock, Driving Time, Satellite Number, Altitude, Driving Distance, and Compass data.
6.2. Display Interface and Settings
The HUD features multiple display interfaces that can be switched and customized.

Figure 6.2: HUD operation showing buttons and display options.
- Switching Display Interfaces: Short press the [M] button to cycle through different display interfaces.
- Entering Settings: Long press the [M] button for 5 seconds to enter the setting menu.
- Navigating Settings: Use the [<] or [>] buttons to navigate between different settings options.
- Confirming Settings: Press the [OK] button to enter or save a setting.
6.3. Demonstration Video
Video 6.1: A demonstration of the A401 Car HUD head-up display's features and functionality.
7. Troubleshooting
If you encounter issues with your Geloo HUD, please refer to the following common solutions:
- No Display/Power: Ensure the OBD2 cable is securely connected to both the HUD unit and the vehicle's OBD2 port. Check the vehicle's power supply.
- OBD Mode Not Working: If your vehicle was manufactured before 2012, it might not be fully compatible with OBD2 mode. Switch the device to GPS mode.
- Inaccurate Readings: Ensure the unit is properly calibrated (refer to the settings menu for calibration options). For GPS mode, ensure a clear view of the sky for satellite acquisition.
- Device Reboots/Freezes: Check the vehicle's voltage. Ensure it is within the 8-18V operating range. A fluctuating or low voltage can cause instability.
- Clearing Fault Codes: The device has a function to clear fault codes in OBD2 mode. Refer to the operation section for instructions on how to access this feature.
For persistent issues not covered here, please contact customer support.
8. Specifications
| Attribute | Value |
|---|---|
| Brand | Geloo |
| Model Number | A401 HUD |
| Material | Acrylonitrile Butadiene Styrene (ABS) |
| Item Dimensions (L x W x H) | 4.49 x 4.45 x 3.03 inches |
| Item Weight | 7.04 ounces |
| Screen Size | 2 Inches |
| Manufacturer | Hot car parts |
9. Warranty and Support
Every Geloo product undergoes strict quality inspection before leaving the factory to ensure reliability and performance. If you have any questions, concerns, or require technical assistance regarding your HUD unit, please do not hesitate to contact the seller, Hot car parts, directly. They will be able to provide further support and information regarding warranty terms.
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