GF40.15-P-0001-05RT Tire Pressure Monitor (TPM), Messages Relevant to Operation
GF40.15-P-0001-05RT Tire pressure monitor (TPM), messages relevant to operation
- with CODE (475) Tire pressure monitor (Siemens)
- up to model year 08
Operation-relevant messages are shown in the multifunction display (A1p13) of the instrument cluster (A1) and indicate to the driver that the air pressure in at least one wheel is changing or has changed. A distinction is made between a "soft warning" (information message) or a "hard warning" (warning message).
The warning messages are displayed in "red".
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.
The operation-relevant messages describe a regular operating condition.
The following messages relevant to operation can occur:
Information messages
If the air pressure in one or more wheels drops > 0.25 bar or 3 psi and not > 0.4 bar or 6 psi below the value set by the driver and the set pressure stored in the TPM [RDK] control unit, then this is shown in the multifunction display.
The information message appears for the first time in the next ignition sequence. The driver is therefore requested to check the tire inflation pressures and to correct them if necessary.
The warning is canceled when filling detection or a manual reactivation is successfully carried out.
This information message is displayed after driving for 30 seconds if the tire pressure monitor (TPM) is not reactivated.
Shown with USA variant pressure display (dimensional unit "psi")
Warning message for unassigned wheels
Function requirements:
^ Detection of rapid pressure loss (> 0.25 bar/min or 3 psi/min) in several tires simultaneously or in an unassigned wheel.
The tire pressure monitor warning lamp in the instrument cluster is also actuated with this warning message and indicates to the driver that the vehicle should be brought to an immediate stop and all tires checked for penetration of any foreign objects. In the interests of driving safety if necessary fit the spare tire or use TIREFIT tire sealant.
The use of TIREFIT means that the corresponding TPM wheel sensor must be replaced.
For USA version, code 494, TIREFIT is not used.
Warning messages
Function precondition:
^ Rapid pressure loss (> 0.25 bar/min or 3 psi/min) in a wheel assigned to a position. In a parallel operation the system activates the tire pressure monitor warning lamp in the instrument cluster.
The driver is urged to stop the vehicle immediately and to check the relevant tires for any foreign bodies which may have entered. In the interests of driving safety if necessary fit the spare tire or use TIREFIT tire sealant.
The use of TIREFIT means that the corresponding TPM wheel sensor must be replaced.
Exemplary display in event of pressure loss in right front tire, shown with USA variant pressure display (dimensional unit "psi")
Warning messages
If the air pressure in one or more tires drops > 0.4 bar or 6 psi below the specified pressure set by the driver and stored in the TPM [RDK] control unit, this is displayed on the multifunction display. Should the pressure loss only occur in one tire, this warning message is displayed as long as the position is not yet assigned.
The tire pressure monitor warning lamp in the instrument cluster is also actuated with this warning message and indicates to the driver that the vehicle should be brought to an immediate stop and all tires checked for penetration of any foreign objects. In the interests of driving safety if necessary fit the spare tire or use TIREFIT tire sealant.
The use of TIREFIT means that the corresponding TPM wheel sensor must be replaced.
This warning message is also displayed, if the TPM control unit refuses to perform an order to activate on the grounds of implausible pressure values.
Implausible pressure values:
^ The tire inflation pressure set by the driver is under the minimum pressure stored in the TPM [RDK] control unit, which must not be dropped below.
^ The pressure difference of the tire inflation pressure on an axle is > 0.4 bar or 6 psi.
Remedy:
^ Correct the tire inflation pressure and reactivate the tire pressure monitor system.
On new vehicles the tire pressure monitor (TPM) is activated by the plant with an increased tire inflation pressure (approx. 3.5 bar or 50 psi). The TPM [RDK] control unit has stored this tire inflation pressure as the specified pressure to be monitored. Correcting the tire inflation pressures in the workshop causes a warning message to appear with circuit 15 "ON".
The tire pressure monitor system (TPM) has to be activated again.
Warning messages
If the air pressure in a wheel that is assigned to a wheel location drops > 0.4 bar or 6 psi below the pressure set by the driver and stored in the TPM [RDK] control unit, this is displayed on the multifunction display in the instrument cluster. The tire pressure monitor warning lamp in the instrument cluster is also actuated with this warning message and indicates to the driver that the vehicle should be brought to an immediate stop and the tire in question checked for penetration of any foreign objects. In the interests of driving safety if necessary fit the spare tire or use TIREFIT tire sealant.
The use of TIREFIT means that the corresponding TPM wheel sensor must be replaced.
Exemplary display in event of pressure loss in right front tire, shown with USA variant pressure display (dimensional unit "psi")
System message after a previous warning messages
If a "red" warning message was issued for a previous circuit 15 "ON", the adjacent tire pressure monitor warning lamp is displayed in the instrument cluster as of the current and for the subsequent circuit 15 "ON", as long as the tire pressure monitor system has not been reactivated by a successful filling detection or manually.
Exemplary display on instrument cluster ECE