ZMFJH P12 Car OBD2 Head-Up Display User Manual

1. Introduction

Thank you for purchasing the ZMFJH P12 OBD smart digital device. This product is designed to enhance your driving experience by connecting to your car's OBD2 interface via an OBD cable. It displays crucial driving data such as vehicle speed, engine RPM, water temperature, and fuel consumption directly in your line of sight, helping you keep your eyes on the road and avoid the dangers of looking down at the dashboard. This device does not alter any car ECU data.

The P12 OBD smart digital device features powerful error code detection. It can display error code information clearly in text form, clear fault codes, and offers accelerating competitive mode and brake performance test mode. It can also read the entire car data stream information, among other functions.

Key Functions & Features:

• Compatible with cars equipped with OBD2 and EUOBD ports (Car automatic diagnosis system), offering plug-and-play functionality.
• Features a TFT LCD multi-color smart display.
• Automatically detects and displays the vehicle protocol upon first scan.
• Supports multiple language options.
• Allows free switching between multi-function display mode and simple function display mode.
• Includes new functions such as accelerating competitive mode and brake performance test, and can read comprehensive car data stream information.
• Provides rich content display including vehicle speed, engine RPM, water temperature, voltage, instantaneous fuel consumption, average fuel consumption, total driving distance measurement, driving time, low voltage alarm, high water temperature alarm, over speed alarm, engine fault code alarm, and the ability to eliminate fault codes.
• Freely switch between kilometers and miles.

2. Package Contents

The following items are included in your P12 Head-Up Display package:

• 1 x P12 HUD Unit
• 1 x OBD Interface Cable
• 1 x Non-slip Mat
• 1 x English User Manual

3. Specifications

4. Setup and Installation

Compatibility Check:

The P12 OBD smart digital device is compatible with cars that have an OBDII or EU OBD agreement. To confirm compatibility:

1. Open the engine hood and look for a sticker that says "OBDII CERTIFIED" (refer to Figure 1 below). If present, the device can be installed.
2. Alternatively, check for a 16-pin diagnostic port located under the steering wheel (refer to Figure 2 below).

Note: For US cars, the device can generally be used after 2003. For most other cars, it can be used after 2007.

Incompatible Vehicles:

The OBD2 working mode is generally not suitable for the following vehicles:

• Almost 98% of cars manufactured before the year 2004 (including the year 2004).
• Some old oil and electricity hybrid vehicles, diesel-powered cars, pickup trucks, SUVs, ORVs, and mini-buses.
• A few specific car models.

Installation Steps:

1. Once compatibility is confirmed, locate the 16-pin diagnostic link in your vehicle.
2. Connect the provided OBDII connecting cable firmly to the diagnostic port.
3. Place the P12 HUD unit on your dashboard using the non-slip mat, ensuring it does not obstruct your view.
4. Start your car engine. The device should power on automatically and begin scanning for the vehicle protocol.

5. Operating Instructions

Device Overview:

Key Functions of the Wheel Button:

The wheel button on the device serves multiple purposes:

• Short press in:
1. Switch the display mode.
2. Confirm the menu selection after entering a menu.
• Push left:
1. Switch the left area functions.
2. Change the function setting after entering a menu.
• Push right:
1. Switch the right area functions.
2. Change the function setting after entering a menu.
• Long press in: After entering a menu and finishing the setting, long press for 5 seconds to save and exit.

Function Abbreviations:

When switching functions using the left/right push, you may see abbreviations:

• ECT: Engine Coolant Temperature
• VLT: Voltage
• RPM: Revolutions Per Minute
• FUE: Fuel Consumption
• TIM: Driving Time
• ODO: Odometer
• DIS: Driving Distance

Multiple Interface Options:

The P12 offers various display interfaces to suit your preferences, with new interface designs providing clearer and smoother graphics.

Setting Mode (Menu Mode):

To enter the setting mode, long press the wheel button. Use the left/right push to navigate through the menu options and short press to confirm a selection. Long press for 5 seconds to save settings and exit.

Available settings include:

• Language Set: Choose your preferred language (English, Simplified Chinese, Traditional Chinese, etc.).
• Sound Switch: Turn the buzzer on or off.
• Speed Alarm: Set the over-speed alarm threshold (default 150).
• Coolant Alarm: Set the coolant temperature alarm threshold (default 120°C).
• RPM Alarm: Set the engine RPM alarm threshold (default 6000 r).
• BAT Alarm: Set the battery voltage alarm threshold (default 10.5V).
• Speed Adjust: Adjust the displayed speed to match your dashboard (default 107%).
• Speed Offset: Adjust if the device shows speed when the vehicle is off.
• BAT Adjust: Adjust if the battery voltage differs from the vehicle's.
• Engine Size: Set your car's displacement (default 1.6 L) for accurate fuel consumption.
• Fuel Adjust: Adjust fuel consumption (default 100%).
• Change Color 1/2/3: Customize the colors of different display areas on the screen.
• Brightness: Adjust display brightness (0 for automatic sensitivity, 1-6 for manual adjustment).
• CWT Unit: Switch coolant temperature unit between °C and °F.
• Speed Unit: Switch speed unit between KM and Miles.
• Sum Distance: Adjust total driving distance to match the dashboard.
• Power Off Time: Set the power off time (default 10s). For auto start/stop cars, set to 180-240s.
• Sleep Voltage: Adjust if the device doesn't auto power off (default off, adjust to 13.2V or higher).
• Factory Set: Short press to restore factory settings.

Driving Test Functions:

• Speedup Test: Displays speed, distance, time for 400m, and time for 100KM/H acceleration.
• Brake Test: Displays speed, brake distance, and time.

PID List (Parameter IDs):

The device can display various PID data from the vehicle's ECU. This includes a wide range of parameters for in-depth diagnostics and monitoring.

Ambient Lighting:

The P12 HUD features cool breathing ambient lighting that can be switched to various colors (dark blue, purple, green, yellow, red) or turned off, allowing you to customize the atmosphere.

6. Troubleshooting

1. Screen without any display, and no power:

• Start the car engine.
• Check if the OBD cable is tightly connected. Try pulling down and re-inserting the OBD cable multiple times to ensure a secure connection.
• Check if the product's power switch is on.
• If still no display, test the device in another car to determine if the issue is with the car's OBD diagnostic interface. If the car's OBD interface is faulty, please repair it.

2. Only shows car voltage and automatically powers off after 60 seconds:

This indicates the device is not receiving proper OBD data. This product is only available for cars with OBD2 agreement and EU-OBD agreement (European region: after 2003; other regions: after 2007). It does not support JOBD and OBDI protocols. Test in another compatible car if possible.

3. Inaccurate Speed:

• First, check if the speed unit (KM/H or MPH) is correctly set in the device settings.
• If the displayed speed is consistently different from your dashboard (e.g., dashboard shows 100, device shows 101), enter the menu, go to settings, and adjust the "Speed Adjust" option.

4. Inaccurate Fuel Consumption:

Check your car's displacement and set the device to match it (e.g., if your car is 2.0L, set the device value to 2.0L). While fuel consumption can be adjusted, it is generally not recommended as all data is read directly from the car's ECU.

5. RPM Alarm:

The default RPM alarm is 6000. Refer to the settings menu to change this value if needed.

6. Over Speed Alarm:

The default over-speed alarm is 150 KM/H. Refer to the settings menu to change this value if needed.

7. The device cannot auto power off:

• If the device still displays speed after the vehicle turns off: Switch the setting to "Speed Offset" and adjust the value to match the device's displayed speed (e.g., if it shows 5KM/H, set the offset to 5KM/H).
• If the device still displays RPM after the vehicle turns off: Switch the setting to "Sleep Voltage" and set the value to 13.2V or higher.

8. Auto start and stop cars:

If you have a car with auto start/stop functionality, change the "Power off time" setting to 180-240 seconds.

9. Wrong operation leads to crashes:

If the device crashes due to incorrect operation, perform a factory reset through the settings menu.

10. Why does it cause the car dashboard fault code to light up?

Universal OBD devices support multiple communication modes, but each car typically supports only one protocol. If your car's dashboard fault code lights up, you may need to adjust the OBD communication protocol by pulling up unneeded pins on the OBD interface. When the vehicle turns on, unplug and re-plug the OBD cable; the device will display the protocol it detects.

Communication Protocol Pin Adjustments:

• ISO15765 CAN Bus: Keep pins 4, 5, 6, 14, 16. Pull up other pins.



• ISO14230 KWP2000: Keep pins 4, 5, 7, 16. Pull up other pins.



• ISO 9141-2: Keep pins 4, 5, 7, 15, 16. Pull up other pins.

7. Warranty and Support

For detailed warranty information and customer support, please refer to the official product page or contact the seller directly. You may also find additional guides and documents, including the full user manual, available as a PDF at the following link: P12 User Manual PDF.