Tire pressure monitor (TPM), messages relevant to the function - GF40.15-P-0001-04TB

Function-relevant messages in the multifunction display (A1p13) of the instrument cluster (A1) show the driver the system status when the current tire pressures and operation-relevant messages cannot be displayed.

Message relevant to the function are divided into:

• System fault(s)
• System messages

System faults are stored in the TPM [RDK] control unit (N88) with a fault code and system messages with an event code.

System messages describe a regular operating condition and in the case of a fault there is no reason to exchange system components.

The following messages relevant to the function can occur:

System fault(s) 

This message appears for:

• Faults in the CAN data bus.
• Failure of a system component.
• At least 1 wheel fitted without left front TPM [RDK] wheel sensor (A69/1), right front TPM [RDK] wheel sensor (A69/2), left rear TPM [RDK] wheel sensor (A69/3) or right rear TPM [RDK] wheel sensor (A69/4).
• The instrument cluster (A1) does not receive any CAN messages from TPM [RDK] control unit (N88) (e.g. cable open-circuit or connector which has fallen off with circuit 15 "On").

  A corresponding fault code is stored in the TPM control unit (N88).

  Fig 1: Screen Display - Tyre Pressure Monitor Inoperative

  Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

System message 

Request for system activation.

This system message is displayed if:

• The TPM [RDK] control unit (N88) has been replaced.
• A red message, relevant to operation, has been displayed in the previous ignition sequences.

This system message is also displayed for approx. 30 seconds each time the vehicle is restarted, as soon as in the TPM [RDK] control unit (N88) the monitoring function has been set to "Not active".

Information message 

This information message is displayed once the request to activate the system has been canceled.

System message 

This system message appears once the system is activated. This is necessary in the event of changes in tire inflation pressure, a tire change or wheel change.

The system can be activated with circuit 15 "On" or when the engine is running.

System message 

This system message is activated for the following criteria:

• At least 1 new left front TPM [RDK] wheel sensor (A69/1), right front TPM [RDK] wheel sensor (A69/2), left rear TPM [RDK] wheel sensor (A69/3) or right rear TPM [RDK] wheel sensor (A69/4) is fitted and is currently taught in.
• An external interference transmitter hinders data transfer.
• Temperature at least of one left front TPM [RDK] wheel sensor (A69/1), right front TPM [RDK] wheel sensor (A69/2), left rear TPM [RDK] wheel sensor (A69/3), or right rear TPM [RDK] wheel sensor (A69/4) > 120°C.
• There is at least 1 additional TPM wheel sensor (A69/1, A69/2, A69/3, A69/4) in the vehicle (e.g. winter wheels in luggage compartment).

  The system message is displayed for a temporary fault in the tire pressure monitor (TPM) system. No repairs are necessary.

  Fig 5: Screen Display - Tyre Pressure Monitor Unavailable

  Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Information message 

The pressure values are only shown following activation, once the system has detected a clear assignment. Until the teach-in process is finished (total driving time approx. 10 min) only the system message opposite is displayed instead of pressure values.

This information message cannot be canceled with the reset button. Pressing the reset button starts the activation again.

Information message 

The transmitter key (A8/1) is located in position circuit 15R "On".

The current pressure values are only displayed with circuit 15 "On" or when the engine is running.

Information message 

Tire pressure monitor (TPM) switched off by means of STAR DIAGNOSIS.

Information message 

The system is in diagnosis mode (complete and correct tire pressure monitoring is not assured).