1. Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of your JVC KD-X38MBS Car & Marine Digital Media Receiver. This unit is designed for use in both automotive and marine environments, featuring a conformal-coated circuit board for enhanced durability against moisture.
Key features include Bluetooth connectivity for hands-free calls and audio streaming, USB input, SiriusXM readiness, and compatibility with the JVC Remote app.

Image 1.1: Front view of the JVC KD-X38MBS Digital Media Receiver.
2. Package Contents
Verify that all items are present in the package:
- JVC KD-X38MBS Digital Media Receiver
- Wiring Harness
- External Microphone
- Installation Hardware
- User Manual (this document)
3. Product Overview
Familiarize yourself with the various components and connections of the receiver.

Image 3.1: Front and rear panel components of the KD-X38MBS. Key components include the Volume Knob, Display Window, Power/Source button, Track Back/Forward, Detach Button, Answer Call, Quick Search, Random Play, Select Music Drive, Repeat Play, Change Display Information, Bluetooth Audio, AUX Input Jack, USB Input Terminal, Fuse, Power Harness Input, SiriusXM Connect Vehicle Tuner Connector, Bluetooth Microphone Input, and RCA Audio Output (Rear/Front/SW).
3.1 Front Panel Controls
- Volume Knob: Adjusts audio volume. Press to access menu options.
- Power/Source Button: Turns the unit on/off and switches audio sources.
- Track/Seek Buttons: Navigates tracks, radio stations, or menu options.
- USB Input Terminal: Connect USB devices for audio playback and charging.
- AUX Input Jack: Connect external audio devices via a 3.5mm cable.
- Display Window: Shows current status, track information, and menu.
3.2 Rear Panel Connections
- Power Harness Input: Connects to the vehicle's power and speaker wiring.
- SiriusXM Connect Vehicle Tuner Connector: For optional SiriusXM tuner.
- Bluetooth Microphone Input: Connects the included external microphone for hands-free calling.
- RCA Audio Output: Provides pre-amp outputs for external amplifiers (Rear/Front/Subwoofer).
- AM/FM Antenna Input: Connects to the vehicle's radio antenna.
4. Installation
Proper installation is crucial for optimal performance and safety. If you are unsure about any steps, consult a qualified technician.
4.1 Safety Precautions
- Disconnect the vehicle's negative battery terminal before installation to prevent electrical shorts.
- Ensure all wiring is properly insulated to prevent damage.
- Do not install the unit where it obstructs the driver's view or interferes with vehicle operation.
- This unit features a conformal-coated PCB for moisture resistance, making it suitable for marine and powersports applications.
4.2 Mounting the Unit
The KD-X38MBS is a single-DIN receiver. Ensure adequate space is available in your dashboard or mounting location.

Image 4.1: Dimensions of the KD-X38MBS receiver: Width 7-3/16" (182mm), Height 2-1/16" (53mm), Depth 3-15/16" (100mm).
- Remove the existing head unit or prepare the single-DIN opening.
- Install the mounting sleeve into the dashboard opening.
- Connect the wiring harness as described in Section 4.3.
- Slide the receiver into the mounting sleeve until it locks into place.
- Attach the trim ring.
4.3 Wiring Connections
Refer to the wiring diagram provided with your unit for specific connections. General connections include:
- Yellow Wire: Constant 12V (Battery)
- Red Wire: Switched 12V (Ignition)
- Black Wire: Ground
- Blue Wire: Power Antenna/Amplifier Remote Turn-On
- Speaker Wires: Connect to appropriate vehicle speakers (e.g., White/White-Black for Front Left, Gray/Gray-Black for Front Right, Green/Green-Black for Rear Left, Purple/Purple-Black for Rear Right).
- Microphone: Connect the external microphone to the dedicated input for optimal hands-free call quality.
5. Operating Instructions
5.1 Basic Operation
- Power On/Off: Press the SRC button.
- Source Selection: Press the SRC button repeatedly to cycle through sources (FM, AM, Bluetooth, USB, AUX, SiriusXM).
- Volume Adjustment: Rotate the large central knob.
- Menu Access: Press the volume knob to enter the menu. Rotate to navigate, press to select.
5.2 Bluetooth Connectivity
The KD-X38MBS supports Bluetooth for hands-free calling and audio streaming.
- Pairing:
- Ensure Bluetooth is enabled on your smartphone.
- Select "Bluetooth" as the source on the receiver.
- On your smartphone, search for available Bluetooth devices and select "KD-X38MBS".
- Confirm the pairing code if prompted.
- Hands-Free Calling: Use the dedicated call buttons on the receiver's front panel to answer or end calls.
- Audio Streaming: Play audio from your paired smartphone. Use the receiver's controls for track navigation.
- JVC Streaming DJ: Connect up to 5 Bluetooth devices simultaneously, allowing multiple users to take turns streaming music.

Image 5.1: JVC Streaming DJ feature, allowing up to five Bluetooth devices to connect simultaneously for shared music streaming.
5.3 USB Playback and Charging
Connect a USB device to the front USB port for audio playback. The port also provides up to 1.5A for rapid smartphone charging.

Image 5.2: Rapid charging of a smartphone using the USB port on the KD-X38MBS.
5.4 Audio Settings
Access the audio menu to customize sound settings:
- Equalizer (EQ): Adjust frequency bands to tailor the sound to your preference. The unit features a 13-band EQ.
- Digital Time Alignment: Optimizes sound staging by delaying audio to individual speakers, ensuring sound reaches the listener simultaneously.
- High-Pass Filter (HPF) / Low-Pass Filter (LPF): Adjust crossover frequencies for speakers and subwoofers.
- Sound Lift: Electronically adjusts the sound stage height.
- K2 Technology: Enhances sound quality by expanding the frequency range and bit rate.
5.5 JVC Remote App
Control the receiver directly from your smartphone using the JVC Remote App, available for both iPhone and Android devices.

Image 5.3: Controlling the KD-X38MBS receiver via the JVC Remote App on a smartphone.
5.6 Display Customization
The receiver features variable-color illumination, allowing you to change the display and button colors to match your vehicle's interior or personal preference.

Image 5.4: Examples of variable color illumination options for the receiver's display.
6. Maintenance
Regular maintenance helps ensure the longevity and performance of your receiver.
- Cleaning the Unit: Use a soft, dry cloth to wipe the front panel. For stubborn dirt, dampen the cloth with water. Avoid abrasive cleaners or solvents.
- Conformal Coating: The unit's conformal-coated circuit board provides protection against moisture and dust, making it suitable for harsh environments. However, direct exposure to high-pressure water jets should be avoided.
- Fuse Replacement: If the unit does not power on, check the fuse located on the rear panel. Replace it with a fuse of the same rating (refer to specifications).
7. Troubleshooting
If you encounter issues with your KD-X38MBS, refer to the following common problems and solutions.
| Problem | Possible Cause | Solution |
|---|---|---|
| No power | Blown fuse, incorrect wiring, vehicle battery issue. | Check and replace fuse. Verify power and ground connections. Check vehicle battery. |
| "SEND PROTECTING SERVICE" message | Internal fault detected, possibly due to wiring error or component failure. | Disconnect power, check all speaker and power wiring for shorts. If the issue persists, contact JVC customer support. |
| No sound | Volume too low, incorrect source selected, speaker wiring issue, amplifier not powered. | Increase volume. Select correct source. Check speaker connections. Ensure external amplifier (if used) is powered on. |
| Bluetooth not connecting | Bluetooth off on phone/receiver, device not paired, interference. | Ensure Bluetooth is active on both devices. Re-attempt pairing. Move closer to the receiver. |
| Date/Time resets | Constant 12V (yellow wire) connection interrupted or faulty. | Verify the constant 12V power connection to the receiver. |
8. Specifications
Detailed technical specifications for the JVC KD-X38MBS.
- Model Number: KD-X38MBS
- Product Dimensions: 7.19"D x 3.94"W x 2.06"H (182 x 53 x 100mm)
- Item Weight: 1.3 pounds
- Connectivity Technology: Auxiliary, Bluetooth, USB
- Controller Type: Built-in Bluetooth (Ver 4.2, Wired-Mic included), Hands Free Call (HFP 1.7.1), 2 Phones Full-Time Connection, Audio Streaming & Control (A2DP, AVRCP 1.6.1), 5 BT-Audio Connection (JVC Streaming DJ), Voice Dialing, Phone Book Access Profile (PBAP), iPhone & Android Automatic Pairing (iPhone only), Low Battery Information.
- Special Feature: 13-Band Equalizer, Digital Time Alignment, Variable Color Illumination, Conformal Coated PCB.
- Compatible Devices: Smartphone, Tablet, Audio Device
- Connector Type: 3.5mm Jack, USB, RCA
- Audio Output Mode: Stereo, Surround
- Pre-amp Outputs: 2-channel (2.5-volt Rear/Subwoofer)
- USB Charging: Up to 1.5A
- Manufacturer: JVC
- Date First Available: April 21, 2022
9. Warranty and Support
JVC provides a limited warranty for this product. Please refer to the warranty card included with your purchase for specific terms and conditions.
For technical support, troubleshooting assistance, or warranty claims, please contact JVC customer service or visit the official JVC website. Keep your purchase receipt as proof of purchase.





