Limp Mode

Low power? Your Mercedes Sprinter or Vito is probably experiencing Limp Mode.

Limp mode is a safety feature of Mercedes vehicles that limits engine power and acceleration when the Engine Control Unit (ECU) detects a fault of any kind.

Common questions about Limp Mode:

How do I know if my Mercedes Sprinter or Vito is in Limp Mode?

Limp Mode will usually limit power to approximately 50% of normal. For most people, this means it is very difficult to accelerate past 60km/h.

Often you will also notice a yellow Engine Light on your dashboard or instrument cluster (note the older 638 Vito and 903 Sprinter do not have an Engine light). If you are experiencing this, then your Mercedes is likely in Limp Mode.

Is my engine broken?

The good news is that your engine is probably OK, rather it’s usually a problem with an ancillary component or sensor.

Specifically, Limp Mode on a Mercedes Diesel will reduce and limit the boost air pressure that the turbocharger makes, via electronic or vacuum control. This is why your Sprinter or Vito is driving slowly.

What is the cause of Limp Mode?

There’s no straightforward answer to this. Limp Mode can be caused by hundreds of different electrical or mechanical defects. Sometimes there can be more that one cause or fault present at once.

However, we are experts at diagnosing and repairing low power problems on not only Sprinter and Vito vans but also Mercedes Diesel Cars and SUVs, so we can tell you a few of the most common causes:

Turbocharger boost pressure too low/high
Turbocharger system leaks or control faults
EGR valve electrical faults
DPF pressure sensor faults
Exhaust temperature sensor faults
Fuel pressure too high/low
Mass Air Flow meter faults
Throttle body electrical faults
Outside air temperature sensor faults
Transmission electrical faults
Fuel Injector electrical faults
Engine monitoring sensor faults
Control module faults, ECU, TCM, ABS, ESP

The Diagnostic process

The first tool that is required is our Mercedes Diagnostic Software (DAS, Xentry, MB Star). We’ll perform a scan of the vehicle’s modules which will show us any stored historical and current fault/error codes. The fault codes will give an indication to the type of fault, but not the exact cause or replacement parts required. Further diagnosis and testing is always necessary.

For example, a common fault code we see is: Charge Pressure Control – Charge Pressure Too Low. This fault refers to the turbocharger system. We know that we have to carry out further inspection and testing of the following systems; Turbocharger, Intercooler, Intercooler Hoses, Intake Manifold, Pressure Sensors, Air Filter, Electronic turbo actuators, Vacuum turbo actuators, Vacuum lines and pump. Once we have completed our mechanical and electrical testing of the relevant systems, we can write a quote on repairs and send our diagnostic inspection report to the customer.

Limp Mode is our specialty!

If your diesel Mercedes is experiencing Limp Mode, we’re the experts you need. We have seen every problem on Mercedes Diesel Vans, Cars and SUVs which means we can get the issue diagnosed and repaired quicker and more accurately than anyone else.

Contact our friendly team today via phone or through our booking enquiry form. We’ll be glad to help.