How Do I Pair My OBD2 Scanner With Bluetooth?

What you need before you start

Pairing goes smoothly when the basics are in place. Most trouble comes from a missing step, not a broken scanner.

Gather these items first:

• The scanner or adapter, plus its manual or quick-start card.
• A phone or tablet with Bluetooth turned on.
• The scanner's companion app, installed from your app store. Many dongles only work through their own app.
• Your car, parked, with the key or start button within reach.

Step 1: Plug in and power up the scanner

Find the OBD2 port. On most cars it is a 16-pin socket under the dashboard on the driver's side, often near the steering column or knee panel. Cars built for North America from 1996 on generally have one. Check your owner's manual if you can't spot it.

Push the scanner in firmly. Then switch the ignition to the on position. Many scanners light up or blink when they get power from the port. Starting the engine is not always required for pairing, but it helps with live data later.

Park first, set the parking brake, and do the plug-in with the car stopped. Keep cables and loose adapters clear of the pedals and steering column.

Pair an OBD2 scanner with an Android phone

Android phones often let you pair a Bluetooth adapter in system settings. The exact menu names vary by phone brand.

Follow these steps:

• Open Settings, then Bluetooth, and turn Bluetooth on.
• Tap the option to scan for or pair a new device.
• Pick the scanner from the list. The name is often a short code or the brand name. Check the manual if you see several unknown names.
• If asked for a PIN, check the manual. Common defaults for budget adapters are 1234 or 0000, but yours may differ.
• Open the companion app and select the same scanner inside its connection or settings screen.
• Run a first scan to confirm that data comes through.

Connect a Bluetooth OBD2 scanner to an iPhone

iPhones work a little differently. Many scanners that use Bluetooth Low Energy do not show up as a paired device in the iPhone's Bluetooth settings. Instead, you connect from inside the scanner's app.

Here is the usual flow. Plug in the scanner and turn the ignition on. Open the app. When prompted, allow Bluetooth access. Then choose the scanner from the app's device list. If the app asks you to add a device, follow its on-screen steps.

If the scanner never appears, check that the app is allowed to use Bluetooth. You can find this in the iPhone's Settings under the app's name. Also confirm the scanner is made for iPhone. Some older or generic Bluetooth adapters only support Android. The product listing or manual should say which phones work.

One example from our spec sheet is the BlueDriver Pro. Its listing says it connects over Bluetooth from your phone or tablet to a 0.13 lb sensor that plugs into the OBDII port. You can compare it with other models on our best bluetooth obd2 scanner page.

Handheld tools with a separate Bluetooth dongle

Some full-system tools are handheld units that use a separate Bluetooth dongle, often called a VCI, to talk to the car. In this setup, the handheld screen is your display and you pair the dongle to the handheld, not to your phone.

The TOPDON AD800BT models are examples. Their listings describe a Bluetooth VCI dongle with a 33 feet (10m) working range. The AD800BT 2 listing mentions a Bluetooth 4.0 VCI. That range figure comes from the listing, so keep the handheld near the car during a scan.

Pairing steps are typically similar. Plug in the dongle, turn the ignition on, power up the handheld, then open its connection or VCI menu and select the dongle. Follow the screen prompts, because menu names vary by model.

If you are still deciding between a phone dongle and a handheld, our best obd2 scanner page puts both styles on one spec sheet.

Fixes when the scanner won't pair

Most failures come down to a few causes. Work through them from the top of this table.

Safety and good habits

Set up the scanner while parked. Do not look at or handle your phone while driving. If you want live data on the road, have a passenger watch the screen.

Never clear codes without writing them down first. Clearing a fault can also reset readiness monitors, which matters before a smog check. Readiness status is a feature on our comparison pages, so check it if emissions testing applies to you.

When you finish, unplug the scanner if the manual advises it. Some adapters can keep drawing a little power from the car. Use the manual's guidance if the car will sit for a long time.

Frequently asked questions

Do I need to start the engine to pair?

Usually the ignition on position is enough to power the port. Some apps need the engine running to show live data. Follow your scanner's manual.

Why does my iPhone not show the scanner in Bluetooth settings?

Many scanners connect only through their own app. Open the app, allow Bluetooth access, and pick the scanner there.

Can one scanner be paired with two phones?

Often only one device connects at a time. Disconnect the first phone or turn its Bluetooth off, then connect the second.

Will pairing work on any car?

Not always. Check the vehicle coverage and system support in the listing, such as ABS, SRS and transmission, before you buy.