AUX3 and BT3 devices

Simple functionality does not mean it has no caveats. Check our most common asked questions below.


Will GROM product fit to my stereo?

Please check our compatibility guide for your car make, model and year fitment and limitations.

What is the difference between Double Din and Single Din stereos?

According to the international standarts for car stereos, head units generally come in either Single DIN (180 x 50 mm panel or 2 inches tall), or double DIN (180 x 100 mm panel or 4 inches tall) size.


How can I connect iPod/iPhone/iPad to GROM-AUX3 system?

iPod/iPhone/iPad can be connected using GROM Compatible iPod Cable Assembly.It will charge, control and playback your music directly through the USB2P interface.
You can also connect your iPhone/iPad and iPod Touch with GROM In-Car Bluetooth Dongle for wireless audio and hands free phone calls.
You can also connect your iPod/iPhone/iPad using GROM AUX and 5V USB charging cable Check our store or add to your cart along with USB2 module.

How many playlists supported on iPod ?

Usually 6. On Toyota, new Honda and Nissan you can have up to 99 folders typically
We recommend using manageable number of playlists ~20

Will the text be displayed?

The text is displayed on select text capable stereos.
Stereos that support text include some BMW, Toyota, Lexus, Honda/Acura (in SAT mode), Mazda (in SAT mode), Subaru (SAT mode). Please check product listing for more detailed information.

What is CDC and SAT Firmware/Mode/Emulation?

CDC is CD Changer emulation. GROM Car Audio Kit emulates CD Changer, and you will use regular CD changer controls to change tracks/disks, control iPod/iPhone/iPad. CDC emulation is available for all GROM compatible cars.
SAT (or XM) stands for Satellite /XM radio emulation. Usually available for cars within United States. If you connected iPod/iPhone/iPad with GROM compatible iPod cable for play, charge and control, you will use Satellite/ XM controls to control your device. Text will be displayed on SAT emulation compatible stereos. Stereo should be SAT/XM capable, but XM/SAT receiver has to be disconnected.
Please check product listing for more detailed information.

How do I switch between AUX/iPod/Bluetooth ?

If using iPod mode then iPod will pause automatically once bluetooth is activated
If AUX mode is used, you need manually pause AUX device when iPod or Bluetooth is activated as AUX is a manual audio source

I have AUX cable and Bluetooth Dongle (GROM-BTD), how to connect them?

AUX cable goes to EXT2 or IPOD connector
BTD always goes to EXT1 or EXT port (center of the box)

I have iPhone or iPod with "Lightning style" connector. How can I connect it to GROM?

In order to connect your iPod or iPhone with the "Lightning style" connector please use Lightning to 30-pin Adapter (0.2 m) from Apple.
We recommend using the adapter with 0.2m cord, especially if you have the case. Make sure you get the genuine Apple adapter.

Can I activate iPhone Siri voice control?

You can activate Siri voice control by pressing Scan button twice.
Please note that your phone should not be in Bluetooth audio streaming mode.

Can GROM-IPD3 power up my cellphone or MP3 player with USB connector?

Yes. It is able to provide steady 1A @ 5V which is enough for most portable devices, make sure you use GROM 35USB cable which provides 3.5mm jack and USB charging


I cannot access CD Changer mode to use the unit

1. Press CD / AUX twice to enter cd changer mode
2. Make sure factory external cd changer (if present) is disconnected
3. Disconnect radio from power for 1-2 minutes. Do not forget to remember the Security code if any !
4. Make sure red LED on Grom circuit board inside enclosure comes on with key. If LED light is not on, double check connections making sure everything is secure with no bent pins. If you have access to a multimeter check for power on pin 19 and 20 of Grom 20pin harness. There will be numbers on the white plastic
5. Update to latest firmware version

Low Volume through aux cable

1. Make sure volume is turned up on your aux device itself
2. Check all connections making sure they are secure, check to see if any change in sound if you wiggle the aux cable or apply slight pressure to 3.5mm side
3. Check with different device to see if any change in volume

I hear noise when GROM is playing

Make sure all connections are secure, double check ground wire if vehicle cable needed to be grounded
Make sure ipod cable is connected securely and is not being blocked by ipod case
Reset ipod
Wiggle ipod cable and apply slight pressure to ipod connector to see if any change, if good sound comes back, contact support

iPod/iPhone does not charge or change tracks

Make sure cables are connected securely to IPOD port with no bent pins
Make sure iPod cable is connected securely and is not being blocked by iPod case

Update "bricked" the unit

Double check that you applied the right firmware to the unit. If you apply Mazda firmware to your Toyota (for ex.) it will disable the device and you will need to apply the right update after you recycle power for GROM-IPD3 box
Then do the following steps:
- Save the latest firmware for your car make on a micro SD card formatted FAT/FAT32
- Make sure you name the file as gromipd3.hex and it resides in the root
- Disconnect the GROM box from white harness
- Insert micro SD into the slot with pins facing down
- Attach the GROM box to the white harness
- The led on circuit board should blink 1-2 seconds and then become solid or go off
- Turn on ignition and switch over to GROM (SAT/CD changer) !

On my radio MIX/RND mode will not allow me to advance tracks in random order

This is dependent on stereo. Turn the MIX/RND mode on and let the track advance in random order upon track completion

While in AUX mode I hear background noise and whine

It is normal when the other end of AUX cable is _not_ connected to anything. Once iPod or MP3 player is connected there will be no noise or whine. If noise is still present after the audio source is connected then contact Technical support.

ID3 tags/text cannot be seen

Make sure all tags are ASCII (no native Chinese, Cyrillic, unsupported special characters, etc)
Make sure the Advanced mode is selected (playlists 2 and up)
Not all stereo support text. Usually VW, Honda are not able to display text.


I cannot pair the phone with the GROM with BT option

1. Please make sure the latest firmware installed
2. Turn the car off. Wait 30 seconds
3. Turn the car on. Now your phone should see the GROM-CAR device. Note that your stereo may be in any mode (FM, AM, CD, SAT etc)
4. Also note that GROM-CAR will be discoverable 3 minutes and if you do not pair the phone you have to repeat items 2-3 again
5. Follow your phone manual and pair it with GROM-CAR
Now the pairing is done and after each ignition start your phone will automatically connect to GROM-CAR !

GROM-CAR is visible but when trying to pair or connect I get an error

BTD module may go into corrupt mode. Do the following sequence:
1. Enable mode switching state (GROM-FM-GROM)
2. Immediatelly press SCAN button few times
3. There should be tw0 voice beeps confirming full reset
You should be able to select and connect to GROM-CAR now

Does bluetooth remember multiple devices? How does it auto connect to one when the car is turned on?

The GROM Bluetooth is capable of pairing up to only 2 devices at a time. It can only connect to one Paired device at a time. It will auto connect to the phone that is nearby when the vehicle is started.

The car came with Bluetooth phone capability but no streaming audio capability. If I hook up the GROM Bluetooth can I use it for the A2DP streaming only, and use the car Bluetooth for hands free calls?

If you have newer smartphone, you should be able to select which paired device will handle phone calls and which will handle music streaming. This is all typically done from the phone Bluetooth settings, and available in iPhone and Android phones.

The phone and GROM syncs at times and on other occasions it will not stream audio.

After first turning on stereo/GROM please give the GROM 10-15 seconds to fully sync with bluetooth before hitting play on device.

My phone is connected to GROM Bluetooth, but there is no sound coming from the speakers.

Make sure that the Bluetooth volume is turned on and all the way up.


I connected my iPod (iPhone or iPad) via GROM compatible cable for iPod, but there is still no control from car stereo or steering wheel. What should I do?

Make sure that you connected the GROM compatible cable for iPod to the EXT2 (right hand side) port of your GROM device. If you connect to EXT1 port the controls will not work.

Can I connect the iPhone or iPad with the latest "Lightning style" connector to GROM device?

Yes you can. You will need to use special Lightning converter, and make sure that it is authentic.