Connecting to Car

Owned by Nils Bluhm
Last updated: Oct 07, 2024 by Momir
5 min read

Due to the variety of connection options available to MHD app users, these instructions to connect to the car are broken down according to connection type.  Sub sections for iOS or Android specifics are provided below where applicable.

Additionally, while it is recommended to always place your device in Airplane mode when flashing, if your device does have a cellular data plan and you wish to keep it active while data logging, we have provided steps that work on most common devices.  We cannot possibly cover all particular devices though (especially Android), so if it does not work for your device you may need to research online or simply keep the device in Airplane mode when using MHD.

WiFi Adapter

The connection process for our MHD WiFi adapter and it is the same process for Android and iOS.

Connecting: first, plug in your MHD WiFi adapter to your vehicle’s OBD-II port.  Wait a few seconds, and then open your devices WiFi network list.  Look for the WiFi network titled like “MHD_xxxx”, and tap it to connect.

Once you are connected to the MHD WiFi network, open MHD.  You can confirm your connection by clicking the “Codes” tab, and then pressing the “Read DME Codes” button with the vehicle running or ignition on.

 

Keeping Cellular Data - Android

Open your device Settings > About Phone.  Scroll to the bottom and locate “Build Number.”  Tap on this quickly 7 times.  This will cause a new menu option to appear called “Developer Options,” at the main Settings page, usually near or above “About Phone.”  Other versions of Android hide it under Settings > System > Advanced Developer Options.  Tap Developer Options, and scroll down until you see “Cellular Data Always Active,” and tap to enable this setting.

 

 

 

ATTENTION:  Be careful using other developer options in that menu, as they can cause issues and unexpected behavior with the MHD app.  We can recommend the “Cellular Data Always Active” option as the only safe option.

 

Keeping Cellular Data - iOS

 

Open your device Settings > WiFi > MHD_xxxx WiFi Network.  You should see a screen like this.  Please make note of your current IP Address, as we will use it in the next step.

Tap on “Configure IP.”  You will see three possible selections at the top, from which you will Select “Manual.”

This will make the fields at the bottom editable.  Enter the following in each of the fields:

  • IP Address: enter your IP Address you made note of above

  • Subnet Mask: 255.255.255.0

  • Router: leave blank!

If you have entered all info correctly, it should look like this.  Press save and then close the Settings app, and you are all set.

ATTENTION:  If you are later (weeks later) unable to connect to your car or WiFi adapter, you may need to revert back to Automatic IP, get a new IP Address, then repeat these steps.

 

Connection Permission with iOS 14 and up

Since iOS 14, It is necessary to grant the MHD app local network access permission, you can do this in Settings -> Privacy -> Local Network.

K+DCan Cable

This connection method is only compatible with Android devices and we ONLY recommend using the MHD WIFI Universal adapter, we do not recommend using any 3rd party connection methods.  In addition to the K+DCan cable, an OTG (on-the-go) adapter is also required.  This adapts your device’s Micro-USB or USB Type-C port to the full sized USB Type-A used on the K+DCan cable.  Please make sure your specific Android device supports OTG.

ATTENTION: It is not uncommon for the OTG adapter piece itself to go bad, so if you rely on this connection method we recommend keeping an extra on hand.

Connecting: simply plug the K+DCan cable into your vehicle’s OBD-II port, the USB end into the OTG adapter, and then plug the OTG adapter into your phone.  You should see the following popup appear (or it will skip immediately to opening an MHD app if you’ve previously set it to “Always open...”

If you have multiple apps installed that can use the K+DCan cable, then instead you will see a window appear that looks like this.  You should not select “Always” in this scenario as it could cause issues with getting the cable to work with one of the other apps later.

After the app launches, you can confirm your connection by clicking the “Codes” tab, and then pressing the “Read DME Codes” button with the vehicle running or ignition on.

 

ENET Cable

This connection method is only compatible with iOS devices and we ONLY recommend using the MHD WIFI Universal adapter, we do not recommend using any 3rd party connection methods.  In addition to the ENET cable, a lightning to ethernet adapter is also required.

Connecting: first, plug the lighting adapter into your iOS device, and then the ethernet plug of your ENET cable into the adapter.  Before connecting the OBD-II end to your vehicle, make sure to turn WiFi off, and also turn on airplane mode.  Next, connect the OBD-II end to your vehicle, open iOS Settings > Ethernet and ensure you see an IP address.  If not, make sure IP Configuration is set to “Automatic IP”.

Open MHD, and you can confirm your connection by clicking the “Codes” tab, and then pressing the “Read DME Codes” button with the vehicle running or ignition on.

 

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