ME-SFI limiting maximum engine speed function - GF07.61-P-3007AM

ENGINE 113.990 in MODEL 211, 219 

ENGINE 113.991 in MODEL 215, 220 

ENGINE 113.992 in MODEL 230 up to Model Year 2008 

ENGINE 113.993 in MODEL 463 up to 31.5.12 

ENGINE 113.995 in MODEL 230 up to Model Year 2008 

Fig 1: Identifying ME-SFI Limiting Maximum Engine Speed Function Diagram

Courtesy of MERCEDES-BENZ USA

The ME-SFI control unit detects the engine speed from the signal supplied by the crankshaft position sensor. To protect the engine and the drive train the engine speed is limited, by:

• Closing the throttle valve in connection with opening the air recirculation flap
• Reducing the ignition angle
• Switching off the fuel injection valves

1. Torque converter protection at selector lever position P/N 

   In order to protect the torque converter in selector lever positions The maximum engine speed is limited to approx. 4200 rpm to protect P and N (no power flow) from excessive static internal pressure.

2. Driving mode 

   In order to protect the engine from the consequences of impermissibly high engine speeds, the maximum engine speed is limited for about 10 seconds to 6700 rpm and after this to 6500 rpm. The driving mode is recognized by the ESP control unit from the vehicle speed signal.

3. Throttle valve actuator defective 

   In the case of a defective throttle valve actuator, the maximum engine speed is limited by switching off the fuel injection valves at about 1500 rpm.

4. Missing version coding 

   If no version coding exists, maximum engine speed is limited to 2400 rpm.

   If the AMG coding is missing, the standard coding for engine 113 is used.