Kenwood KDC BT31U Manual

The Kenwood KDC BT31U is a single-DIN car stereo with Bluetooth connectivity, USB port, AUX input, CD player, AM/FM radio, and 50W x 4 maximum power output. Features include hands-free calling, audio streaming, front panel detachable security, and customizable audio settings. Below are key sections for features, installation, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. Basic Operation 4. Specifications 5. Controls and Settings 6. Bluetooth Connectivity 7. Audio Sources 8. Security Features 9. Care & Maintenance 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Main unit with detachable front panel, remote control, wiring harness, mounting sleeve, user manual.

Feature	Description
Bluetooth	Hands-free calling and audio streaming
USB Port	For USB devices and charging
AUX Input	3.5mm auxiliary input for external devices
CD Player	Plays CD, CD-R, CD-RW formats
AM/FM Tuner	30 station presets (18 FM, 12 AM)
Power Output	50W x 4 maximum power
Detachable Face	Security feature to prevent theft
EQ Settings	Bass, Treble, Loudness controls
Display	LCD with adjustable illumination
Remote Control	Included for convenient operation

Installation

Unpack and inspect all components before installation.

Disconnect negative battery terminal for safety.
Remove existing stereo from dashboard.
Connect wiring harness following color codes:
- Yellow: Constant 12V
- Red: Switched 12V
- Black: Ground
- Blue: Power Antenna/Amplifier
Secure unit with mounting sleeve.
Reconnect battery and test operation.

WARNING! Professional installation recommended. Ensure proper grounding and fuse protection.

Basic Operation

Power on unit by pressing SRC button. Select source mode (Radio, CD, USB, BT, AUX).

Volume Control: Turn knob or use remote VOL+/- buttons.
Source Selection: Press SRC to cycle through available sources.
Radio: Tune with TUNE buttons, store presets by holding number button.
CD: Insert disc label side up, playback starts automatically.
USB: Connect device, unit will detect and begin playback.

CAUTION! Do not operate while driving. Set all controls before driving.

Specifications

Power Output: 50W x 4 (Max), 22W x 4 (RMS)
Frequency Response: 20Hz - 20kHz
Signal-to-Noise Ratio: >80dB
Bluetooth Version: 2.1 + EDR
Supported Audio: MP3, WMA, AAC
CD Formats: CD, CD-R, CD-RW
USB Support: Up to 32GB FAT32
Power Supply: 12V DC negative ground
Dimensions: 178mm (W) x 50mm (H) x 160mm (D)

Controls and Settings

Front Panel: Power/Volume knob, SRC button, Function button, Eject button.

Remote Control: Power, Volume, SRC, Play/Pause, Track Up/Down, Preset buttons.

Audio Settings: Bass (-6 to +6), Treble (-6 to +6), Loudness (On/Off), Balance/Fader. Display: Dimmer control, Button illumination. Radio: Auto store, Local/DX reception. System: Reset, Beep tone, Bluetooth settings.

Bluetooth Connectivity

Pair mobile device for hands-free calling and audio streaming.

Enable Bluetooth on mobile device.
Press and hold BT button until display shows "PAIRING".
Select "KDC-BT31U" from device list on phone.
Enter PIN "0000" if prompted.
Connection confirmed when display shows device name.

Tip: Up to 5 devices can be paired. Only one can be connected at a time.

Audio Sources

Multiple source options available:

Radio: AM/FM with 30 presets, seek and manual tuning.
CD: Play, pause, skip, repeat, random play modes.
USB: Supports MP3/WMA files, folder navigation.
AUX: Connect external audio devices via 3.5mm jack.
Bluetooth Audio: Stream from paired devices.

WARNING! Do not insert damaged discs. Keep USB devices secure while driving.

Security Features

Detachable Front Panel: Remove for theft prevention. Security Code: 4-digit code can be set to disable unit if stolen.

Care & Maintenance

Clean with soft, dry cloth only. Do not use chemicals or solvents.

CAUTION! Avoid extreme temperatures and moisture. Store detachable face in protective case.

Regulatory Information

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Wiring/fuse	Check fuse, wiring connections, and ground.
No sound	Mute/settings	Check mute function, volume level, speaker connections.
Bluetooth not connecting	Pairing/range	Re-pair device, ensure within range, check phone settings.
CD not playing	Disc/loading	Check disc format, clean disc, ensure proper insertion.
USB not recognized	Format/capacity	Ensure FAT32 format, check capacity limit, try different device.

Reset: Press reset button on front panel with small object.

Service: Contact authorized Kenwood service center for repairs.