2. Disconnect plug 1 of crankshaft position sensor 2 to prevent the engine from starting when the starter cranks the engine (see illustration).
Warning! Jacking up a vehicle and placing it on jack stands can pose a risk of injury. For this reason, please familiarize yourself with the safety precautions before performing the above work.
3. Place the vehicle on jack stands and remove the front part of the engine protection (mudguard), see the relevant chapter.
4. Apply chalk mark 2 on the groove belt 1 in a place where it will be clearly visible (see arrow in illustration).
5. Check the condition of the belt along its entire length by slowly turning the engine with the starter until the applied mark appears.
[Material created based on the website: MercedesMAN]
6. Inspect the V-belt. Make sure it is free of oil and grease. When the belt is worn, its longitudinal ribs run together at an acute angle (see part B in the illustration). The ribs of the new belt have a trapezoid shape. The ribs of the belt move away from the cord and it is visible (see part C in the illustration). Other damages to the V-belt include:
- a) transverse cracks D on the back side of the belt (see illustration 10.6a);
- b) detachment of part E of the ribs (see arrow in illustration 10.6a);
- c) fraying, fringe of the F cord on the side surfaces (see illustration 10.6b);
- d) G cord breaks (see illustration 10.6b);
- d) transverse cracks H on several ribs (see illustration 10.6b);
- e) breaks in the J ribs of the belt (see illustration 10.6c);
- g) transverse cracks K on the ribs (see illustration 10.6c);
- c) deposits between the belt ribs;
- i) rolling of the rubber base of the belt.
If there is at least one or more of the above damages, the V-belt must be replaced, see the relevant chapter.
7. Turn off the ignition and remove the key from the ignition switch.
8. Inspect the electric radiator fan drive belt, if present, by gradually rotating the fan.
9. Connect the crankshaft position sensor plug.
Attention! The self-diagnosis system registers disconnection of the crankshaft position sensor plug as a malfunction. In this regard, it is recommended to contact a workshop to read and delete the malfunction codes.
10. Read the registered fault codes and clear them.