Tire pressure monitor control unit, task - GF40.15-P-3000-03D
Models 215, 220 as of 1.9.02 with code (475), tire pressure monitor
The tire air temperature is taken into account in the comparison of the current tire inflation pressure with the stored specified pressure. These values are read in by the TPM wheel sensors (A69/1, A69/2, A69/3 and A69/4) and passed on by the TPM wheel antennae (A2/44, A2/45, A2/46 and A2/47) to the TPM [RDK] control unit (N88). Furthermore, various other conditions are evaluated which are read in via CAN class B (see the following input signals via CAN).
From this the TPM [RDK] control unit (N88) calculates the limit values valid for the current tire air temperature.
If these limit values are dropped below, the TPM [RDK] control unit (N88) passes on an appropriate CAN signal to the instrument cluster (A1) depending on the pressure deviation. This CAN signal is processed in the instrument cluster (A1) and the corresponding information conveyed to the driver via the multifunction display (A1p13) (display color: yellow or red).
On vehicles as of 1.10.03 the tire pressure monitor warning lamp in the instrument cluster (A1) is actuated in parallel with a red warning message. This only goes out after the system is reactivated.
Direct input signals
Left front TPM [RDK] wheel antenna (A2/44),
Right front TPM [RDK] wheel antennaA2/45
Left rear TPM [RDK] wheel antenna (A2/46) and
Right rear TPM [RDK] wheel antenna (A2/47):
- Tire inflation pressure in question and
- Tire air temperature
Input signals via CAN
Left front SAM control unit (N10/6):
- Outside temperature
Right front SAM control unit (N10/7):
- Circuit 61 (engine running)
Rear SAM control unit (N10/8):
- Trunk lid status
ESP, SPS [PML] and BAS control unit (N47-5):
- Wheel speed
AIRmatic with ADS control unit (N51) or
ABC [Active Body Control] control unit (N51/2):
- Vehicle level
Electronic ignition switch control unit (N73):
- Output of circuit status
Steering column module (N80):
- Requests via scroll forward/back button (S110s1) and button + and -, adjustment of specific functions and volume control (S111s1) in the multifunction steering wheel