Tire pressure monitor control unit, task - GF40.15-P-3000-03T

Model 211

Fig 1: Tire Pressure Monitor Control Unit Communication Diagram

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Task

When comparing the actual tire pressure with the stored nominal pressure, the temperature of the tire is taken into account. The TPM control unit (N88) calculates valid limits for the actual tire temperature.

If the tire pressure falls below these limits, the TPM control unit (N88) passes an appropriate CAN signal to the instrument cluster (A1) according to the pressure deviation. This CAN signal is processed in the instrument cluster (A1) and the appropriate information is displayed for the driver on the multifunction display (A1p13).

Input signals:

Left front TPM [RDK] wheel antenna (A2/44)
Right front TPM [RDK] wheel antenna (A2/45)
Left rear TPM [RDK] wheel antenna (A2/46)
Right rear TPM [RDK] wheel antenna (A2/47)
Power supply, terminal 30

Via the CAN-engine compartment there is a connection to:

Instrument cluster (A1)
Driver-side SAM control unit with fuse and relay module (N10/1)
EIS [EZS] control unit (N73)
Central gateway control unit (N93)

The following information is processed:

Instrument cluster (A1)

Initializing

Driver-side SAM control unit with fuse and relay module (N10/1)

Outside air temperatures
Terminal 61 ON (to detect "engine running")

EIS control unit (N73)

Wheel speeds
Circuit 15 ON

Central gateway control unit (N93)

Country code
Engine/body variant
Diagnosis active

The following information is issued via the CAN-engine compartment:

Instrument cluster (A1)

Tire pressures
Messages relevant to function
Messages relevant to operation

Central gateway control unit (N93)

Diagnosis