How to use the OBD-II, Bluetooth, and Your Phone to troubleshoot your Mercedes-Benz
All Mercedes-Benz cars manufactured after 1996 are equipped with an OBD-2 port, mandated by federal regulations. OBD stands for On-Board Diagnosis.
The OBD-II port allows you access to your car’s Engine Control Unit (ECU) which monitors, RPMs, sensors, emission, mileage speed and an array of other parameters. When there is a problem with the car the ECU triggers a Diagnostic Trouble Code (DTC) or Fault Code by illuminating the Service Engine / Check engine on your instrument cluster. If you were greeted by Check Engine Light, you could retrieve the codes using your phone (iPhone or Android) and a Bluetooth Adapter as a scanner. You can use a device such as Veepeak Mini WiFi OBD2 OBDII OBD II Scanner Scan Tool Adapter or any OBD-II Bluetooth Adapter on Amazon Best Selling Code Reader list.
If the Check Engine or Service Engine Soon light is on your car, and is staying on or flashing, here is what you need to do.
How to connect the Bluetooth Adapter to the OBD II port and your Smartphone
1. Locate the OBD-II port on your car. It is located under the dashboard on driver’s side. The port is typically either black or white. Look above the brake pedal and you will be able to see it. The port has sixteen pins. Some of the pins may be missing depending on the signal protocol used by the manufacturer. This port is required by federal law and will work with any scan tool that is OBD II compatible.
2. Plug in the Bluetooth adapter into the OBD II port. Make sure that the lights turn on in your Bluetooth adapter.
3. Pair your phone with the adapter. Go to your phones settings, turn on Bluetooth. Then search for Bluetooth devices. You will see an OBD II device discovered. Click on it and you should be asked for a pairing code. Try 1234 or 0000. If these two codes don’t work, read the manual for the Bluetooth adapter to find out what code the manufacturer used.
5. Download and open up your App and make sure it is connected to the Bluetooth adapter. You will be able to stream live engine data such as RPMs, temperature, engine load and more. More importantly, you can hit Read Fault Codes and retrieve the trouble codes for you Mercedes-Benz.
6. Once you see the list of error codes, click on the Menu button and hit Clear / Erase Fault Codes. Please note that you should only delete the fault codes if the problem has been repaired. If you erase the fault codes without fixing the problem, the check engine light will turn on again. Depending on what triggered the check engine light initially, it may turn on right away or it could take a few days to come.
The Bluetooth adapters are great as not only can they read and erase the service engine light, but they also can be used to stream real-time information. A Bluetooth adapter paired with a good app can provide valuable information such as:
- Stream Realtime Information
- Check / Read Fault Codes DTC
- See Test Results
- Provide Graphing
- Display a tachometer or accelerometer
- Record your 0-60 or 0-100 mph times.
- Stream RPM
- Fuel Flow Rates
- Temperature of coolant, oil or intake air
Depending on the adapter that you use you may be able also to store profiles, get fuel economy readings, and horsepower.
Using an OBD2 Bluetooth Adapter as a scan tool is a great way to troubleshoot your Mercedes-Benz via the OBD-II port. Not only will you be able to read and erase the fault codes (diagnostic trouble code), but you can use your phone to see if you are driving efficiently and check if you are ready for the emissions test.
To monitor your car, you will need an OBD II Bluetooth adapter. Our recommendation is to Veepeak Mini OBD scan tool adapter for the check engine light. If you have an Android phone choose the Bluetooth For Android version or if you have an iPhone or iPad use the WiFi for iOS.
Another Bluetooth scanner that is highly rated works with most car models without problems is the BlueDriver Bluetooth Professional OBDII scan tool which also works on iPhone, iPad, and Android. The BlueDriver adapter has several advanced features and comes with a free App and free future updates. It also provides free vehicle specific repair reports.Note that these Bluetooth OBDII scanners only read and erase the check engine light. If you need to read and clear codes from other control units such as ABS, SRS, ETS, TCU and more you will need a professional scanner such as Launch Creader Viii Complete System Scanner.