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

ENGINE 113.986 

ENGINE 113.987 

ENGINE 113.988 

ENGINE 113.989 

Fig 1: ME-SFI Limiting Maximum Engine Speed - Function - Engine 113.986/987/988/989

The ME control unit (L5) detects the engine speed via the crankshaft position sensor signal (N3/10). For protection of the engine and the drive train the engine speed is limited, by:

• Reduction of the opening angle of the throttle valve actuator (M16/6)
• Take-back of ignition angle
• Cutout switch on fuel injection valves (Y62)

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

   In order to protect the torque converter in selector lever positions In order to protect "P" or "N" (no power flow) against increased static internal pressure the maximum engine speed is limited to approx. 3800 rpm.

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 3 seconds to 6,700 rpm and after this to 6,500 rpm. The driving mode is detected from the vehicle speed signal.

3. Throttle valve actuator defective 

   If the throttle valve actuator is defect then the maximum engine speed is limited by the cutout switch on fuel injection valves to about 1,500 rpm.