Tire pressure monitor (TPM), messages relevant to operation - GF40.15-P-0001-05SXU

On vehicles with tire pressure monitor (TPM) the messages relevant to operation are shown in the multifunction display (A1p13) of the instrument cluster (A1). The messages ensue in "yellow" (information messages) or in "red" (warning messages).

When "red" warning messages appear, the tire pressure monitor warning lamp (A1e66) in the instrument cluster is activated.

Messages relevant to operation are stored in the TPM [RDK] control unit (N88) with an event code.

Messages relevant to operation describe a regular operating condition. In the event of a complaint there is no need to exchange system components.

Message relevant to operation (soft warning with yellow display), shown on model 221 up to 31.8.06

If the air pressure drops for more than 12 minutes (in one wheel or several wheels) by 0.25 bar under the specified pressure stored in the TPM control unit and adjusted by the driver, this is shown in the multifunction display.

Fig 1: Identifying Display Message Relevant To Operation (Soft Warning With Yellow Display)

Courtesy of MERCEDES-BENZ USA

With "terminal 15 OFF" the due tire pressure correction is indicated. The driver is therefore requested to check the tire inflation pressures and correct them if necessary and then reactivate the tire pressure monitor TPM system.

This message acknowledges itself. It disappears after 30 s when it is no longer actuated.

Warning message (hard warning with red display), shown on model 221 up to 31.8.06

A pressure loss (more than 0.2 bar/min) has been detected.

The tire pressure monitor warning lamp is also actuated.

Fig 2: Identifying Display Warning Message (Hard Warning With Red Display)

Courtesy of MERCEDES-BENZ USA

The driver is requested to stop the vehicle immediately and to check all tires for foreign bodies which may have penetrated.

To make the vehicle safe to drive the spare tire is to be fitted if necessary or TIREFIT tire repair kit used.

Replace the corresponding TPM wheel sensor after using TIREFIT.

Warning message (hard warning with red display), shown on model 221 up to 31.8.06

A rapid pressure loss has been detected.

In addition the tire pressure monitor warning lamp in the instrument cluster is actuated.

Fig 3: Identifying Display Warning Message (Hard Warning With Red Display)

Courtesy of MERCEDES-BENZ USA

The TPM [RDK] control unit has stored the air pressure of the tires in each case as the specified pressure to be monitored.

A warning message is also displayed with "terminal 15 OFF" after correcting the tire inflation pressure.

The TPM [tire pressure monitor] system must be reactivated.

The TPM system is activated with an increased tire inflation pressure (approx. 3.5 bar) on new vehicles at the plant.

System error message shown on model 221 up to 31.8.06

Here wheels without TPM wheel sensors have been installed.

Fig 4: Identifying Display System Error Message

Courtesy of MERCEDES-BENZ USA

System error message shown on model 221 up to 31.8.06

Here the TPM system has been switched off on account of a serious fault.

The TPM system is faulty.

Fig 5: Identifying Display System Error Message (TPM System Faulty)

Courtesy of MERCEDES-BENZ USA

System error message shown on model 221 up to 31.8.06

Possible cause:

Over/under voltage
Interference transmitter

Fig 6: Identifying Display System Error Message (Tire Pressure Monitor Currently Unavailable)

Courtesy of MERCEDES-BENZ USA

Operating feedback after reactivation, shown on model 221 up to 31.8.06

The driver has carried out reactivation via the operating menu in the instrument cluster.

Fig 7: Identifying Display Message For Operating Feedback After Reactivation

Courtesy of MERCEDES-BENZ USA