GF40.15-D-0001H Tire Pressure Monitor, Function
GF40.15-D-0001H Tire Pressure Monitor, Function
Networking of components, shown with code (JK3) High-end instrument cluster standard with speedometer in km up to 31.12.2010
A1 Instrument cluster
A2/110 Front RDK decoder antenna
A2/111 Rear RDK decoder antenna
A69/1 Left front TPM [RDK] wheel sensor
A69/2 Right front TPM [RDK] wheel sensor
A69/3 Right rear TPM [RDK] wheel sensor
A69/4 Left rear TPM [RDK] wheel sensor
N73 EIS [EZS] control unit
N80 MRM control unit
N88/1 TPM [RDK] control unit
Networking of components, shown with code (JK3) High-end instrument cluster standard with speedometer in km up to as of 1.1.2011
A1 Instrument cluster
A2/111 Rear RDK decoder antenna
A69/1 Left front TPM [RDK] wheel sensor
A69/2 Right front TPM [RDK] wheel sensor
A69/3 Right rear TPM [RDK] wheel sensor
A69/4 Left rear TPM [RDK] wheel sensor
N73 EIS [EZS] control unit
N80 MRM control unit
N88/1 TPM [RDK] control unit
General
The tire pressure monitoring (TPM) system permanently monitors the tire inflation pressure while the vehicle is being used. At specific intervals the individual serial number (ID) for each wheel sensor is recorded and the tire pressure as well as the tire interior temperature measured. The recorded data are sent over the following paths:
- For vehicles up to 31.12.2010:
The collected data is transmitted over a radio signal path to the front RDK decoder antenna, rear RDK decoder antenna and then over the local interconnect network (LIN) to the TPM [RDK] control unit.
- For vehicles as of 1.1.2011:
Over a radio signal path to the TPM [RDK] control unit (with integrated antenna for reception of the left front TPM wheel sensor and the right front TPM wheel sensor) and to the rear tire pressure monitor antenna decoder. The rear tire pressure monitor antenna decoder forwards the data over the LIN to the TPM [RDK] control unit.
The TPM system assists the driver with monitoring the correct tire inflation pressure and thus serves the purpose of active safety. The driver is informed of the current tire inflation pressure via the display (A1p1) in the instrument cluster.
The tire pressure monitor system serves to enhance the safety through prevention:
^ A tire blowout, occasioned by excessive flexing and fast driving at an air pressure that is too low, is prevented.
^ The driver is requested to check the tire inflation pressure.
^ An advance warning is issued in the event of rapid pressure drop (pressure drop > 0.2 bar/min.).
^ Regular checking of the tire inflation pressure is thus simplified.
The TPM system does not relieve the driver of a regular manual check of the tire inflation pressure (at least every 14 days). The table on the driver seat box can be used to set the correct tire inflation pressure. The tire pressure monitor system does not warn against tire inflation pressures that are too high, but only against implausible ones.
System components of the TPM system
The tire pressure monitor system consists of the following components:
^ TPM [RDK] control unit
^ Left front TPM [RDK] wheel sensor
^ Right front TPM [RDK] wheel sensor
^ Right rear TPM [RDK] wheel sensor
^ Left rear TPM [RDK] wheel sensor
^ Front tire pressure monitor antenna decoder (up to 31.12.2010)
^ Rear RDK decoder antenna
Controls of tire pressure monitoring (TPM) system with code (JK3) High-end instrument cluster standard with speedometer in km
The tire pressure monitor system is operated using the following buttons of the multifunction steering wheel (MFL):
^ System select button (S111s3)
^ Scroll forward/back button (S111s1)
^ + and - button (S110s1)
Controls of tire pressure monitoring (TPM) system except code (JK3) High-end instrument cluster standard with speedometer in km
The tire pressure monitor system is operated using the following buttons on the instrument cluster:
^ Plus button (A1s3)
^ Minus button (A1s4)
^ "M" button
TPM system display
The warning and status messages of the TPM system are shown on the display of the instrument cluster in the case of vehicles with and without code (JK3) High-end instrument cluster standard with speedometer in km. With certain warning messages, the RDK indicator lamp (A1e29) is also actuated.
Networking and information flow
The information flow and networking are organized as follows:
- On vehicles up to 31.12.2010:
- The signals from the wheel sensors (left front TPM [RDK] wheel sensor; right front TPM [RDK] wheel sensor; right rear TPM [RDK] wheel sensor; left rear TPM [RDK] wheel sensor) are received by the front RDK decoder antenna and the rear RDK decoder antenna and transmitted to the TPM [RDK] control unit via LIN.
- The TPM [RDK] control unit evaluates the signals taking the acceleration and steering angle values into consideration (when cornering at > 30 km/h) and sends all operating and function-relevant information, that are to be displayed to the driver, as signals to the interior CAN (CAN B).
- The instrument cluster reads in the TPM [RDK] control unit signals from the interior CAN and actuates the display and the RDK indicator lamp to match.
- For vehicles as of 1.1.2011:
- The signals of the left front TPM wheel sensor and right front TPM wheel sensor are received by the TPM [RDK] control unit. The signals of the right rear TPM wheel sensor and left rear TPM wheel sensor are received by the rear tire pressure monitor antenna decoder and sent over the LIN to the TPM [RDK] control unit.
- The TPM [RDK] control unit evaluates the signals using the wheel rotation direction (right/left detection period 9 min.). The TPM [RDK] control unit determines the axle allocation and sends all operational and function-relevant information, that are to be displayed to the driver, as signals over the interior CAN (CAN B).
- The instrument cluster reads in the TPM [RDK] control unit signals from the interior CAN and actuates the display and the RDK indicator lamp to match.
Function up to 31.12.2010:
The left rear TPM wheel sensor and the right rear TPM wheel sensor each send a data package to the front tire pressure monitor antenna decoder. The right rear TPM wheel sensor and left rear TPM wheel sensor each send a data package to the rear tire pressure monitor antenna decoder, which contain the air pressure, the individual serial number, the tire's interior pressure and the wheel rotation direction. The TPM [RDK] control unit receives the data from the wheel sensors via the front RDK decoder antenna and via the rear RDK decoder antenna. The data is transmitted from the front RDK decoder antenna and rear RDK decoder antenna to the TPM [RDK] control unit via LIN. For an initial start-up or a new initialization the axle localization is initially conducted by evaluating the reception level for the tire pressure sensors, and then the side localization through evaluating the rolling direction information. The side localization can take a while to complete.
Function as of 1.1.2011
The left front TPM [RDK] wheel sensor and right front TPM [RDK] wheel sensor each send a data packet TPM [RDK] control unit, the right rear TPM wheel sensor and left rear TPM wheel sensor each send a data package to the rear tire pressure monitor antenna decoder, which contain the air pressure, the tire's interior pressure, the individual serial number and the wheel rotation direction. The TPM [RDK] control unit receives the data from the front wheel sensors over an integrated antenna and the data for the rear wheel sensors over the rear tire pressure monitor antenna decoder. The data are sent from the rear tire pressure monitor antenna decoder over the LIN to the TPM [RDK] control unit. For an initial start-up or a new initialization the axle localization is conducted by evaluating the reception level of the tire pressure sensors. Position identification is already defined by the right/left recognition.
The wheels are positioned within 9 minutes.
Initial start-up and re-initialization
These cases are treated in identically the same way by the TPM [RDK] control unit. After assignment of the wheel sensors to the corresponding position has been completed, the air pressures set for the tires are stored as specified variables. These values are maintained, until the tire pressure monitor system is initialized again or the tire is inflated again.
