Calibrating BMW N54 Injectors With An Autel MX808
Injector replacement is part of owning an N54 powered BMW. The Autel MX808 makes the calibration process of your new fuel injectors a little easier with no special software necessary.
Calibrating the flow rates for direct injectors is a requirement on some vehicles when installing new injectors. The reason why injector calibration or flow adjustments need to be made electronically via the DME is because each injector is slightly different from the next. The DME needs to know this to "balance everything out", so to speak. In this case, we'll be talking about the N54 injector calibration specifically; showing you the step by step instructions on how to do this with an Autel MX808. This is one of the easier aftermarket tools to do this job with for any user. I have used BMW factory software before (INPA and ISTA/D) to do this work before and I like the fact that I don't need to use a laptop and special cables to perform this type of work. You can go from basic system scanning right into basic system service functions with the same tool which I find extremely convenient. Follow along and we'll show you what to do with the MX808 to perform the calibration process.
Step 1: Replace the Injectors
We have a complete article and video on how to replace the injectors on an N54 engine. The critical step during the injector install is to record the two three-digit calibration numbers off the injector.
Step 2: Plug the MX808 into the OBD2 Port
This is an easy step but one worth mentioning. Plug in the MX808 into the diagnostic port with the included OBD2 cable. You will hear an audible beep emit from the scanner when it's turned on and plugged into the port. This verifies that the scan tool is communicating with the vehicle and there is power at the OBD2 port. The vehicle should be in accessory mode (key on and engine not running).
Step 3: Select "Service"
Next select "service" on the main menu of the Autel scan functions.
Step 4: Select "Injector" from the service menu option list
You will see a series of icons. Click the labeled injector icon.
Step 5: Select Vehicle Make
Select the BMW icon
Step 6: Read the Vehicle VIN
First you will select "automatic selection". Then you will have two options for the VIN entry. You can either manually enter the VIN or let the scanner read it for you. I recommend letting the scanner read for you. If it works, it will enter the VIN. Verify that the VIN matches and then select "OK".
Step 7: Verify Vehicle Information on the Next Table
You will see a table that gives you vehicle information. In this case, the scanner is plugged into an E61 535xi. Just confirm the information is correct and then select "yes".
Step 8: Wait for the Scanner to Load System Data
This may take a minute or two. You will see a page shortly after with communication data as well as a loading bar. Sit tight and let the scanner process
Step 9: Select "Hot Function"
You will have an option between "diagnosis" or hot function. Select the "hot function" option.
Step 10: Select "Injection Quantity Compensation"
This should be your only option on this menu. Select "injection quantity compensation" and wait for the next page to load.
Step 11: Was a New DME Installed?
This next page asks if you installed a new DME. Unless you replaced it, click no as you will be overwriting existing calibration numbers on the DME.
Step 12: Review Existing Adjustment Values
Not much to see here. This is just a list of each adjustment value for each cylinder currently stored. Select "continue".
Step 13: Select "F2"
This will take you to the value adjustment page. Select "F2".
Step 14: Enter Which Cylinder You Want to Make a Compensation Adjustment On
You can either enter the cylinder number or use the drop down option. You can only calibrate one compensation value at a time.
Step 15: Enter the Top and Bottom Number From the Compensation Values on Injector in one row of numbers
Look at the values you wrote down earlier from each injector. Take the top number and bottom number and enter them in a single row. After entering, you can select "OK".
Step 16: Verify the Adjustment Value Entered in the Last Step Matches the Correct Cylinder
If everything matches up properly, select "yes". Once you've completed this, you will then be prompted to turn off the ignition.
At this point you will get a page that shows the stored compensation values. Please note that these values do not match up one-hundred percent to what you entered, as the DME will change these numbers slightly. This is completely normal and part of the coding process. You will repeat the process for each cylinder that has a swapped injector. Compared to the BMW specific software and much more expensive scan tools, the MX808 gets this job done easily and affordably. The menu system is straight-forward enough that anyone can complete the re-calibration process.
If you want to learn more about how to work on your BMW yourself, you can continue reading our blog or subscribe to our YouTube channel.
Written By: Gareth Foley
Gareth is the BMW Catalog Manager for FCP Euro and has been with the company since 2012. Gareth's BMW obsession started with a hand me down E39 528i when he was 17. From this car he learned how to do his own repair work while also learning more about BMW. When Gareth was at CCSU studying Marketing he had the opportunity to go to SEMA with the college car club. This is where he developed his love of the automotive industry. Since joining FCP in 2012 Gareth has sought out to develop one of the broadest and most accurate BMW replacement parts catalog. he can be reached at email@example.com