Notes on MOExtended tires - AH40.10-P-0010-01A

Model 164, 166, 169, 171, 172, 197, 203, 204, 207, 209, 211, 215, 216, 218, 219, 220, 221, 230, 245, 251

Design

MO Extended stands for Mercedes Original Extended tires This is a tire with a reinforced sidewall which in the case of a pressure loss supports the weight resting on the wheel and makes it possible to continue driving to a limited extent. The SA MO Extended is permanently coupled to a tire pressure monitoring system. This can be a tire pressure loss warning (RDW) indirect measurement system or a tire pressure monitor (TPM) direct measurement system. Use of MO Extended tires without air pressure monitoring is not permissible as through the stable sidewall a pressure loss can only be detected with difficulty or not at all.

Notes

The following items must be observed before the use of MO Extended tires:

A sensor must be fitted to each wheel on vehicles with the tire pressure monitor (TPM) direct measurement system.
Commercially available valves without sensors must be fitted to vehicles with the tire pressure loss warning (RDW) indirect measuring system.
Wheels of older model series are not designed and safeguarded for the higher MO Extended loading. Therefore MO Extended tires may only be fitted on the model series on which according to the overview for disk wheels an MO Extended tire is also offered.
MO Extended tires should only be fitted on Mercedes-Benz wheels in order to avoid a reduction in component service life.
A repair is not permitted on damaged MO Extended tires.

Advantage

The use of MO Extended tires offers the following significant advantage:

Extended mobility i.e. in the event of tire damage there is the possibility of exiting critical areas such as highways or tunnels.

Emergency running distance

The emergency running distance depends of the road condition, the driving style as well as the loading condition of the vehicle and is:

approx. 30 km in the fully laden condition
approx. 80 km in the partially laden condition.

It starts with the appearance of the pressure loss warning message in the multifunction display.

By using TIREFIT the emergency running distance can be significantly increased in the event of minor damage.

If an air loss occurs in one or more tires the driving characteristics should be adapted accordingly. The permissible maximum speed of 80 km/h must not be exceeded otherwise the emergency running characteristics are no longer provided.

If a tire has been driven with low air pressure, the wheels, valves and wheel sensors in question are to be checked for damage in order to safeguard the function of the system.

Method of functioning of tire pressure monitor (Beru), shown on model 219

Fig 1: Tire Pressure Monitor Functioning Diagram (Shown On Model 219)

Courtesy of MERCEDES-BENZ USA

The driver adjusts the required tire pressure in all wheels. After this the tire pressure is stored in the TPM control unit via the button + and D, adjustment of specific functions and volume control (S111s1) on the multifunction steering wheel (N88).

While driving, the system now compares the existing tire pressure in each wheel with the stored values every 3 or 4 seconds. If a difference is measured, the driver is informed immediately via the multifunction display (A1p13) in the instrument cluster (A1).

Functionality of tire pressure loss warning system, shown on model 219

Fig 2: Tire Pressure Loss Warning System Functioning Diagram (Shown On Model 219)

Courtesy of MERCEDES-BENZ USA

The tire pressure loss warning (RDW) itself takes place without the position of the affected tire being given and is only active from a speed of 15 km/h. In the Electronic Stability Program system or Sensotronic Brake Control system, a highly accurate evaluation of the wheel speeds transmitted by the rpm sensors (L6/1 to L6/4) is performed when the vehicle is being driven a moderate driving style. If a speed difference is now measured, this means that a tire has a pressure loss. The error message is lead directly to the instrument cluster (A1) and is displayed to the driver in the form of an information message in the multifunction display (A1p13).

For each check or adaptation of tire pressure as well as for each wheel or tire change the tire pressure loss warning (RDW) system must be restarted (see operator's manual).