Mercedes-Benz W202 (C-Class 1993–2000, including the S202 estate): common faults, maintenance guides and repair tips.
The most common cause is the plastic gear in the mechanism having lost its teeth, or the nut on the motor shaft linkage having come loose. If the moto...
The most common causes are oxidised contacts in the multifunction stalk (the control lever next to the steering wheel), the multifunction relay in the...
A common cause is the multifunction relay, which controls the indicators, wipers and rear window heating. Solder joints on its circuit board crack. Re...
Most often the fault is in a sensor and not in the coolant level. The cause may be the expansion tank level sensor, the windscreen washer fluid sensor...
The most common cause is the fan control box, whose regulator part can overheat and burn out. Replacing the control box has most often fixed the fault...
The most common cause is a thermostat stuck open: the temperature stays at about 50–60 degrees and does not rise. Replacing the thermostat usually nor...
It is a common cause. Other symptoms are running on fewer cylinders after a cold start, white smoke, grey engine oil, and oil or mayonnaise-like paste...
The most common causes are the two solenoid valves in the engine bay, which stick in the wrong position, or a faulty climate control panel. A blown fu...
The causes are usually worn or dry bearings in the blower motor and worn brushes. The noise can be louder in frost and change with the speed....
The most common causes are the series resistor, worn brushes in the blower motor, an oxidised fuse or weak solder joints in the climate control panel....
When air gets into the fuel line, the pump does not get fuel but sucks air. Starting takes longer, especially on a car that has stood overnight. Air b...
A common cause is the injection pump or its control electronics, for example the Lucas pump of the OM601 engine. First it is worth checking that no ai...
Usually one or more glow plugs are dead, and the light tells you so. The alternatives are the glow relay or the fuse inside it; the relay is in the bl...
The most common cause is a faulty brake light switch, which gives the control unit a wrong signal. Other causes are the wheel speed sensors and their ...
Common causes are a faulty wheel sensor or its wiring (the front sensors break more easily), a fault between the sensor and the ABS ring, the YJ relay...
Once the car has stood and its devices have gone to sleep, the standby current should be under 100 mA, typically 40–80 mA. With the alarm it can be ab...
The most common causes are worn-out alternator brushes, a faulty voltage regulator or a broken alternator exciter wire. Sometimes the cause is also a ...
Often it is. You can check a coil by swapping the coils with each other: if the fault moves with the coil, the coil is broken. A multimeter can show a...
Not in all versions. In the 1.8 and 2.0 litre M111 petrol engines the air quantity is estimated from the intake manifold vacuum sensor, the throttle p...
The most common causes are a dirty or faulty throttle body, the mass air flow sensor (MAF) and an intake air leak. First try cleaning the throttle bod...
Switch the ignition on and listen for the pump hum. Make sure there is fuel in the tank and that fuel comes out of the filter's inlet pipe. If the pum...
Typical causes are the conductor plate inside the gearbox and its connector, the gear selector, the speed sensor signal and too low a charging voltage...
A plain change of about 3.5 litres leaves about half of the old oil in the gearbox. That is why the oil change is worth doing as a flush; the flush ne...
The lever releases only when the ignition is on and the brake pedal is pressed; if the system works, you hear a click. The fault can be a faulty brake...
The most common cause is a missing or worn rubber bushing on the gear shift rod or the gear lever. Replace the rubber bushings and check the centring ...
The cause is usually the clutch master or slave cylinder. If fluid runs under the mats, the fault is in the master cylinder at the pedal end. If fluid...
No play should be felt in the bearing in the vertical direction. In the horizontal direction a small amount of play may be felt when cold. The front a...
The replacement interval is roughly 180–200 thousand km. The joints usually wear at the same time, so it is not worth replacing one joint alone. Check...
The causes can be worn outer joints of the lower control arm, the adjusting rods or the front rubbers of the rear subframe. They are replaced when the...
The most common cause is a refrigerant leak. Typical leak points are the compressor shaft seal, the front core of the condenser, the pressure pipe mou...
1. Loosen the automatic adjuster under the rear seat with a hex key. 2. Adjust the shoes through the wheel bolt hole close to the drum or disc. 3. Tig...