Liiiyuan P21 Head-Up Display: Digital Speedometer User Manual

1. Product Overview

The Liiiyuan P21 is a dual-system LCD car head-up display designed to project essential vehicle data directly onto its screen, allowing drivers to view information without looking down. This enhances driving safety by keeping the driver's eyes on the road. The device can be positioned for optimal visibility.

Image: Liiiyuan P21 Head-Up Display installed on a car dashboard, showing speed and RPM.

2. Key Features

• Dual Mode Operation: Supports both GPS and OBD2 modes. The device comes with one OBD cable, enabling use in either mode.
• Comprehensive OBD Display: Shows vehicle speed, water temperature, voltage, fuel consumption, RPM, clock, single driving time, driving distance, intake pressure, oil temperature, air-fuel ratio, throttle position, intake temperature, transmission temperature, engine load, tilt angle, acceleration test, and brake test.
• Detailed GPS Display: Provides vehicle speed, voltage, satellite time, altitude, number of satellites, driving direction, single mileage, driving time, uphill and downhill angle, left and right tilt angle, acceleration test, and braking test.
• Multiple Alarm Functions: Includes overspeed alarm, speed alarm, water temperature alarm, voltage alarm, coolant temperature alarm, RPM alarm, and tilt alarm.

Image: Visual representation of the various data points and parameters displayed by the P21 HUD.

Image: Depiction of the five primary alarm functions available on the P21 HUD.

3. Package Contents

Upon opening the package, please ensure all the following items are present:

• Liiiyuan P21 Head-Up Display Unit
• Suction Cup Holder
• OBD Cable
• Double-sided Adhesive Tape
• Instruction Manual

Image: All components included in the Liiiyuan P21 Head-Up Display package.

4. Setup & Installation

4.1 Choosing a Location

Select a flat, non-obstructive area on your dashboard where the display will be clearly visible without impeding your view of the road. The device can be secured using the provided suction cup holder or double-sided adhesive tape.

Image: Various placement options for the P21 HUD on a car dashboard.

4.2 Connecting the Device

The P21 supports both OBD2 and GPS modes. The connection method depends on your preferred mode and vehicle compatibility.

• OBD2 Mode: Applicable to most gasoline cars manufactured after 2008. Locate your vehicle's OBD2 port (typically under the dashboard near the steering wheel). Connect the provided OBD cable to the port and then to the P21 unit.
• GPS Mode: Applicable to any car. If your car is pre-2008 or does not support the OBD2 protocol, you must use GPS mode. Connect the GPS cable (if provided separately, or use the OBD cable which supports both) to the P21 unit. The device will search for satellite signals to display data.

Important Note: If your car does not meet the OBD protocol, please switch to GPS mode within 5 seconds of powering on the device.

Image: Illustration of the two power cord options for the P21 HUD: OBD cable and GPS cable.

5. Operating Instructions

5.1 Display Modes

The P21 offers multiple display interfaces to suit your preference. You can cycle through these interfaces using the control buttons on the device.

Image: Examples of the 11 different display interfaces available on the P21 HUD.

5.2 Alarm Settings

The device features customizable alarm thresholds for various parameters. Refer to the detailed instruction manual for specific steps on how to adjust these settings.

6. Troubleshooting

If you encounter any issues with your Liiiyuan P21 Head-Up Display, please refer to the following common troubleshooting tips:

• No Display/Power: Ensure the cable is securely connected to both the device and the vehicle's power source (OBD2 port or USB). Check your vehicle's fuse box if using OBD2 mode.
• No Data in OBD2 Mode: Verify your vehicle is compatible with OBD2 mode (most gasoline cars after 2008). If not, switch to GPS mode. Ensure the engine is running.
• No Data in GPS Mode: Ensure the device has a clear view of the sky to acquire satellite signals. This may take a few minutes upon initial startup or in areas with poor signal.
• Inaccurate Speed Reading: The speed display can usually be calibrated through the device's settings menu. Consult the full instruction manual for calibration steps.
• Alarms Triggering Incorrectly: Adjust the alarm thresholds in the device settings to match your preferences and local regulations.

For further assistance, please contact Liiiyuan customer support.

7. Specifications

8. Warranty & Support

Liiiyuan products undergo thorough quality inspections before leaving the factory. We offer comprehensive after-sales service. For any unresolved issues within one year of purchase, please contact us directly via email for support.