GF40.15-P-0001-02RE Tire Pressure Monitor (TPM), Activation
GF40.15-P-0001-02RE Tire Pressure Monitor (TPM), Activation
Tire pressure monitoring (TPM) assists the driver in constantly monitoring the correct tire inflation pressure. If the driver changes the tire inflation pressure, wheel(s) or a tire, the set air pressure values must be saved in the TPM [RDK] control unit (N88) as the desired monitoring values.
The tire filling pressure to be monitored can be manually determined by the driver by "reactivation" of the tire pressure
monitor via the operating menu in the instrument cluster (A1). The temperature-compensated pressure thresholds for the warnings are set based on the pressure values at the time of reactivation.
Manual reactivation is only planned as a stopgap solution in critical cases where automatic filling detection fails. Under normal circumstances (wheel exchange or driver sets new pressure values) new specified values are automatically determined by the filling detection function.
Reaction of the TPM [RDK] control unit after manual reactivation
If the tire pressure values are plausible to the TPM [RDK] control unit, both individually and in relation to each other, and over the minimum pressure specified for the model series, reactivation is carried out. The operating acknowledgement "Tire pressure monitor reactivated" is immediately shown. The current tire pressures are accepted as specified values on an axle by axle basis.
Conditions for the acceptance of current pressure values as new specified values:
- Pressure values screened for three minutes
- On-board wheel detection completed
- Plausibility check on pressure values carried out
- Determination of specified pressure values carried out after a positive plausibility check
Conditions for reinitialization of filling detection:
- Engine switched back on after more than three minutes idle time
- TPM wheel sensor signals a pressure change when vehicle is stopped
- New on-board wheels detected after start of trip
Requirements for filling detection:
- Filling detection started
The TPM system can be reactivated in the following cases:
- After tire pressure change (e.g. from refilling)
- After every wheel or tire change
- After fitting new wheels or tires
- No pressure change (temperature compensated) of more than 0.1 bar (max/min value comparison) within monitoring period
- Tire pressures are above minimum pressure specified for the model series
Description of operation
The TPM system is permanently operational is not actively controlled by the driver. Each time the CAN-B (Controller Area Network bus class B (interior)) is alerted by the starting procedure or ignition "ON" (circuit 15), the TPM [RDK] control unit performs a reinitialization and starts to transmit signals to the instrument cluster. Reactivation of the TPM system can be initiated via the left multifunction steering wheel button group (S110) and the right multifunction steering wheel button group (S111) on the multifunction steering wheel and the instrument illumination rheostat and reset button (A1r1) on the instrument cluster.
Note: When the TPM system is reactivated filling detection is also restarted.
System message (request to activate system)
Reactivate tire pressure monitor:
- Correct the air pressure at each wheel
- "Ignition ON" (circuit 15)
- Select the standard display with the system selection button (S110s3)
- Use the scroll forward/back button to select the TPM system
System message (information message)
The following message appears:
- After starting engine
- If the vehicle is parked for more then 20 minutes
- If the vehicle is driven faster then 25 km/h
Reactivate tire pressure monitor:
Press the instrument illumination rheostat and reset button
The display changes to the selected screen with preselection "no"
Press the + and - buttons for setting specific functions and volume control on the multifunction steering wheel.
The selection screen with selection "yes" appears for approx. two seconds and then changes immediately to the confirmation screen.
Reactivation of tire pressure monitor carried out
From this point on the TPM system monitors the (re) set tire inflation pressure values of all rotating wheels. The TPM system has stored the current tire pressure as a new reference value.
All other buttons cause the activation sequence to be aborted.