Pioneer DEH-S31BT Audio Receiver Wiring Diagram
Complete diagram
Every cable and connector on the unit and where each one goes.
Terminals and components · 14
- Constant 12 V
- Switched 12 V
- Ground
- System remote
- Illumination and preamp
- Speakers
- AUX input
- Connectors
- Antenna and devices
Caution
Do not let the lead wind around the steering column or shift lever; secure it with clamps.
Hubs
Connection through a USB hub is not supported.
Settings
Turn the AUX setting on in the menu to use it.
Separate screws
The power amp ground and this unit's ground go to the body with different screws. A loose screw can cause smoke, fire or malfunction.
Caution
Do not run it to the battery through the hole into the engine compartment.
Fuse
The rear of the unit has a 10 A fuse: replace it only with one of the same rating.
No ACC position
If the ignition switch has no ACC position, connect it to a terminal that detects the key; otherwise the battery will drain.
Never to a power terminal
Never connect it to the power terminal of an amp or auto antenna: it may drain the battery or cause a malfunction.
Glass antenna
If the vehicle has a glass antenna, connect it to the antenna booster power supply terminal.
Caution
Tape any unused speaker leads. With a two-speaker system, do not connect anything to the spare leads.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Caution
Tape any unused speaker leads. With a two-speaker system, do not connect anything to the spare leads.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Caution
Tape any unused speaker leads. With a two-speaker system, do not connect anything to the spare leads.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Caution
Tape any unused speaker leads. With a two-speaker system, do not connect anything to the spare leads.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Plugs
L = left, R = right; connect with RCA cables (sold separately).
Subwoofer
The subwoofer output is monaural.
Speaker leads
The eight speaker leads with their polarity, with four speakers or with a subwoofer on the rear leads.
Terminals and components · 4
- Speakers
- Unused
Caution
Tape any unused speaker leads. With a two-speaker system, do not connect anything to the spare leads.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Caution
Tape any unused speaker leads. With a two-speaker system, do not connect anything to the spare leads.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Caution
Tape any unused speaker leads. With a two-speaker system, do not connect anything to the spare leads.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Caution
Tape any unused speaker leads. With a two-speaker system, do not connect anything to the spare leads.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Setting
With a subwoofer on the rear leads, set the rear output to subwoofer (SW) in the menu.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
Setting
With a subwoofer on the rear leads, set the rear output to subwoofer (SW) in the menu.
Negative leads
Do not ground the speaker negative lead or band it together with other speakers' negatives.
2 Ω subwoofer
A 2 Ω subwoofer (or two 4 Ω subwoofers in parallel) goes only to the violet and violet/black leads and must be rated over 70 W. Connect nothing to the green and green/black leads.
Setting
With a subwoofer on the rear leads, set the rear output to subwoofer (SW) in the menu.
2 Ω subwoofer
A 2 Ω subwoofer (or two 4 Ω subwoofers in parallel) goes only to the violet and violet/black leads and must be rated over 70 W. Connect nothing to the green and green/black leads.
Setting
With a subwoofer on the rear leads, set the rear output to subwoofer (SW) in the menu.
External power amp
RCA outputs to the amplifiers and the lead that turns them on.
Terminals and components · 3
- Preamp
- System remote
- Amplifier
Amp turn-on
Connect it to the system remote terminal of each amplifier.
Plugs
L = left, R = right; connect with RCA cables (sold separately).
Subwoofer
The subwoofer output is monaural.
About This Diagram
These diagrams are redrawn from page 3 of the Pioneer DEH-S31BT Audio Receiver manual, and we offer them completely free and in English. We have also categorized it in the Car Audio & Stereo (Automotive) section on Diagramverse, and it has been rated by 1 user with an average rating of 5.0. If you have any specific questions about the Pioneer DEH-S31BT Audio Receiver Wiring Diagram, we suggest checking the Frequently Asked Questions (FAQs) section.
Printable Pioneer DEH-S31BT Wiring Diagrams
Wiring Instructions
Before you start
The Pioneer DEH-S31BT is built for 12 V negative ground vehicles only. It runs on 14.4 V DC (10.8 V to 15.1 V allowable), draws up to 10.0 A, and is protected by a 10 A fuse in the power cord. Before you plug in anything, work out which tab of the diagram matches your system:
- Complete: four speakers on the harness, with an optional amplifier on the RCA output.
- Speakers: pick the variant that matches your speakers. Use Four speakers for a normal front and rear setup, 4 Ω subwoofers for one 4 Ω subwoofer on each rear channel, 2 Ω subwoofer for a single 2 Ω subwoofer with no amplifier, and Two 4 Ω in parallel for two 4 Ω subwoofers that together make a 2 Ω load.
- Power amp: an external amplifier fed from REAR/SUB OUT.
Tools and materials: a digital multimeter, wire strippers, crimp connectors or solder and heat-shrink, electrical tape, cable clamps, and a vehicle-specific harness adapter and dash kit if your car needs them. The sources don't specify a wire gauge. If you have to extend a lead, match or exceed the gauge of the original wire. Never shorten the unit's own cables, and never cut into the power cable insulation to power other devices. Its current capacity is limited.
Disconnect the battery negative terminal before you begin. Pioneer warns that installing car electronics without training can be dangerous. If your installation needs drilling or other changes to the vehicle, or the car has complex factory wiring, have a qualified installer or your dealer do the job.
Step-by-step wiring
- Find the vehicle's circuits with the multimeter before you disconnect the battery. Look for one wire that shows 12 V at all times (this one goes to Yellow) and one that shows 12 V only with the key in ACC or ON (this one goes to Red). Label both, then disconnect the battery negative.
- Connect Black: chassis ground first. Run it to clean, paint-free metal on the body, and tighten the screw firmly. If you have an amplifier, it needs its own ground screw, separate from the head unit's.
- Connect Yellow: constant 12 V to the constant supply terminal. Don't route the yellow lead through the firewall directly to the battery.
- Connect Red: switched 12 V to the terminal controlled by the ignition switch. If your ignition has no ACC position, use a terminal that detects key operation. Otherwise the unit can drain the battery.
- Connect the speaker pairs: FL (White +, White/Black −), FR (Gray +, Gray/Black −), RL (Green +, Green/Black −), RR (Violet +, Violet/Black −). Keep each negative lead on its own speaker. Never ground a negative lead, and never join the negatives of different speakers.
- For a single 2 Ω subwoofer, or two 4 Ω subwoofers in parallel, use only Violet and Violet/Black. Tape the unused Green and Green/Black leads separately. A subwoofer on the rear speaker leads must be rated over 70 W, and full-range speakers must be rated over 50 W at 4 to 8 Ω.
- If you use an amplifier or a power antenna, connect Blue/white: system remote to the amplifier's system remote terminal or the auto-antenna relay control terminal. It supplies 300 mA max at 12 V DC. If the car has a glass antenna, connect it to the antenna booster power supply terminal instead. Never connect it to the power terminal of an amplifier or an auto antenna.
- Run RCA cables from REAR/SUB OUT to the amplifier. The DEH-S31BT has only this one pair of RCA outputs.
- Plug the vehicle antenna into ANT. Plug the microphone into MIC and mount it on the sun visor or steering column in front of the driver. Clamp its lead so it can't wrap around the steering column or shift lever. If you have a steering wheel adapter, connect it to REMOTE.
- Cover any connectors you don't use with insulating tape. Secure the wiring with clamps, and tape it wherever it touches metal. Keep it away from seat rails, the shift lever and heater outlets.
- Mount the unit in the supplied sleeve, bending the metal tabs over, at an angle of less than 60°. Leave space behind it so it can shed heat.
Testing and start-up
Reconnect the battery negative. Before you slide the unit fully home, measure about 12 V on Yellow at all times and on Red only with the key in ACC or ON. Remove the front panel and press the RESET button with a pointed tool longer than 8 mm. When you turn the ignition on, the setup menu should appear.
Next, open the INITIAL settings and match them to your wiring. Set REAR-SP to FUL for rear full-range speakers, or to SW for a subwoofer on the rear speaker leads with no amplifier. Set SP-P/O MODE to tell the unit what the RCA output feeds: REAR/SUB.W, SUB.W/SUB.W or REAR/REAR. If you use a subwoofer, set SUBWOOFER to ON in the AUDIO settings.
Then test each channel at low volume with FADER and BALANCE. Check that the amplifier and power antenna come on with the unit and turn off with it. Finally, pair a phone and make a test call to check the microphone.
Safety notes
- Never bypass the fuse or fit a larger one. Use only the 10 A rating specified.
- A loose ground screw can cause fire, smoke or malfunction. Recheck it after the first drive.
- Never use 1 to 3 Ω speakers on the four-channel outputs. Only one channel (violet) accepts a 2 Ω load.
- Keep the unit away from moisture and liquids.
- Don't install it where it could get in the way of driving or injure a passenger in a sudden stop.
Troubleshooting
| Symptom | Probable Cause | What to Check |
|---|---|---|
| Unit won't turn on at all | Blown 10 A fuse, no 12 V on Yellow or Red, or a bad Black ground | Check the fuse in the power cord. With the key in ACC, measure about 12 V from Yellow to chassis and from Red to chassis, and check that Black reads near 0 Ω to bare metal. |
| Radio forgets the clock and presets every time I turn off the car | Yellow and Red are swapped, or both are on switched power | With the key off, Yellow should still read about 12 V. If it reads 0 V, move it to a constant 12 V source. |
| Car battery goes dead overnight | Red on constant power, Blue/white on a power terminal, or Bluetooth left on standby | With the key off, Red should read 0 V. Make sure Blue/white goes only to an amp remote or antenna relay control terminal. On cars with no ACC position, use a key-detect terminal for Red. |
| Display shows AMP ERROR | A speaker lead is shorted, grounded, or joined with another speaker's negative, or the load is too low | Disconnect the battery and look for stray strands. Make sure no negative lead touches the chassis and each speaker pair is separate. Check that the impedance is 4 to 8 Ω per channel, or 2 Ω only on violet. Then cycle the ignition. |
| Amplifier or power antenna doesn't turn on | Blue/white not connected, or the device needs more than 300 mA | With the unit on, measure about 12 V on Blue/white. If the load needs more than 300 mA, drive it through a relay. |
| Weak, thin bass and voices sound hollow | One speaker wired with reversed polarity | Check that the plain color goes to + and the black-striped wire goes to − on every speaker, then retest. |
| 2 Ω subwoofer sounds distorted or the unit cuts out | Subwoofer wired to the green leads, or a 2 Ω load on a full-range channel | Move the subwoofer to Violet and Violet/Black and tape Green and Green/Black. Set REAR-SP to SW. |
| No sound from the amplifier connected to the RCA jacks | Output mode set wrong, or a loose RCA plug | Set SP-P/O MODE to match the system, and set SUBWOOFER to ON if you're feeding a subwoofer amp. Reseat the RCA plugs at REAR/SUB OUT. |
| Fader or subwoofer menu options are missing | INITIAL settings don't match the wiring | Rear speaker options are hidden when REAR-SP is set to SW or SP-P/O MODE is set to SUB.W/SUB.W. Change these to match what is actually connected. |
| Radio reception is weak or stations fade | Antenna plug not fully seated, or the antenna booster isn't powered | Reseat the plug in ANT. On a glass antenna, check for 12 V at the booster supply from Blue/white when the unit is on. |
| Callers can't hear me | MIC plug loose, or the microphone is badly placed | Push the plug fully into MIC and mount the microphone in front of the driver. A lowered sun visor reduces pickup. |
