Home Articles Mercedes MBE 900 Turbo Boost Performance Code Troubleshooting

Mercedes MBE 900 Turbo Boost Performance Code Troubleshooting

Troubleshooting and Repair “turbo boost performance code”

Mercedes MBE 900 Diesel Engine

The Turbo Boost Performance code means just what it says. There is a low boost reading that the motor control module (MCM) has detected and that’s the reason for the fault code on the dash.

The Detroit Diesel Diagnostic Software is a tool you MUST have when troubleshooting any electronically operated diesel engine.

Without diagnostic software you’re shooting in the dark and you won’t have a very good chance finding the problem. You may get lucky but the cost and time will hurt you in the long run.

Start With The Basics

The basic checks are always good to follow. Since this is related to turbo boost the charge system, air filter and a physical check of the boost pressure will help you get started.

However nothing beats having the software in your hands as I demonstrate in the video. You just hook up and read the code and the details associated with it. The boost performance is low so according to the troubleshooting directions the first thing to check after the preliminary inspection is to pull out the turbo boost sensor.

Inspecting Boost Sensor

The boost sensor has to be inspected for soot build up. In this case as you saw in the video it’s caked with soot. It’s not recommended to clean the sensor so replacement is necessary.

My cost for one of these sensors is twenty four dollars. That is a very reasonable price considering the average cost of electronic parts and accessories.

I happen to have one of these sensors in stock and it takes 5 minutes to replace it. The software will update the code status after you cycle the key. I started the engine for a few minutes to see if the new sensor fixed the problem. And it definitely did the trick. The code disappeared and the next step was a road test.

Road Testing Is The Final Test

The road test proved that the “turbo boost performance code” was gone. Another advantage of having the software at hand is the ability to run diagnostic tests. If you wanted to find out what the turbo boost was on a road test you can look it up. There is no more hooking up a pressure gauge having to physically watch the boost while driving under load.

Forced Regeneration Using the Diagnostic Software

After I got back from the road test a regeneration was necessary because of the DPF (diesel particulate filter) being in zone one. This is not severe yet but it’s always a good practice to keep up with forced regens to keep the system clean.

We are doing this every oil change now as a preventive maintenance measure to help avoid too much soot building up in the emissions system.

Thanks for reading….if you enjoyed this post share it with others and make a comment. I will be posting more troubleshooting posts as they happen in the fleet.