Tire Pressure Monitoring System (TPMS), System Overview.

Tire Pressure Monitoring System (TPMS), System Overview.
- 44 06 06 Aug.10, 20062010267, Supersedes T.B. Group 44 number 05-03 dated September 14, 2005 due to updated information.

Technical Background
- This technical bulletin / overview was designed to assist the technician, and supply a better understanding of the TPMS system to prevent return repairs

Production Solution
- No production change required.

Service

OVERVIEW
- When repairing the Tire Pressure Monitoring System (TPMS) use the following as an overview.

Components:
- Left Front Tire Pressure Monitoring Sensor -G222-.
- Right Front Tire Pressure Monitoring Sensor -G223-.
- Left Rear Tire Pressure Monitoring Sensor -G224-.
- Right Rear Tire Pressure Monitoring Sensor -G225-.
- Spare Tire Pressure Monitoring Sensor -G226-.
- 1 central antenna to receive all signals (goes straight to the Comfort and Convenience Control Module -J393-.
- The Comfort and Convenience Control Module -J393- houses the TPMS control module -J502-.

FUNCTION

Tire Pressure Monitoring Sensors:
- Mounted to tire stem of each individual wheel.
- Battery life of approximately 10 years.
- Activated by centrifugal motion (wheel rotation) or by pressure increase or decrease.
- Wheel rotation of 25 km/h (16 mph) or above will start signal that includes tire pressure, tire temperature, tire acceleration and identification number.
- Even without tire rotation, a pressure increase or decrease will cause the sensor to send a signal.
- 315 MHz transmission frequency.
- .45 grams in weight.

Antenna
- Central Locking and Anti-Theft Alarm System Antenna -R47- receives signals from tire pressure sensors.
- -R47-, located behind the left A-pillar, goes directly to Comfort and Convenience Control Module -J393-, which is located behind the glove box.

Tire Pressure Monitoring Control Module -J502-
- Functions are performed by the Comfort and Convenience Control Module -J393-.
- Does not identify where sensors are, only information from sensors that are sending signals.
- Controls tire pressure warning lamp on instrument cluster.

Install the correct pressure per pressure label on the vehicle. If the ambient temperature outside the workshop where the vehicle is operated is lower, add pressure to compensate. Example: 20°C (68°F) inside the shop, -20°C (-5°F)outside night time temperature. The temperature difference is sufficient to exceed the O.4bar (5.8psi) threshold and to illuminate the warning light. There is no upper threshold pressure warning.

Tire Pressure Warning Lamp -K230-
- Will illuminate yellow without sound in combination with warning message in the MFI should a tire pressure concern occur.
- Use VAS 5052 and GFF to perform diagnosis.
- When tire pressure is 0.4 to 0.5 bar (6 to 7 psi) below nominal, Message in cluster reads "Tire Pressure Too Low".
- Rapid loss of pressure of more than 0.2 bar (3 psi) per minute. Message in cluster reads "Low Tire".

GENERAL SYSTEM FUNCTION DESCRIPTION
- As the tires spin, signals are sent from the sensors (located in each wheel) to the -R47- antenna. This antenna is connected to the Comfort and Convenience Control Module -J393-. The Tire Pressure Monitoring Control Module -J502- is integrated into -J393-.

- -J502- will determine if pressure in the tire is correct. If it is not correct, a yellow warning lamp will illuminate without sound on the instrument cluster and a message will display in the Multi Function Indicator (MFI).

Tip:
Adding pressure to a tire and driving the car will stop the lamp from illumination and is not covered by warranty.

Changing tires or replacing sensors may create a customer concern, as the system take 20 minutes to go in a learn mode for sensor and control unit (see Diagnosis, Adaptation).

Tire Filling
- Check tire pressure using VAS 5216 or equivalent.
- Tires must be filled when cold.
- Pressure displayed on the scan tool is delayed for approximately 20 seconds while filling is completed.

Tip:
Filling the tire and driving the car will stop the lamp from illuminating and is not covered by warranty.

Adaptation
After replacing a sensor or changing to a spare tire, the TPMS system must be re-learned by performing the following:

Vehicle must be parked for a minimum of 20 minutes before the TPMS system will go into learn mode.

- Start vehicle and drive 25 KM/h (16 mph) for at least 7 minutes.
- TPMS then recognizes sensor inputs.
- Warning light in cluster will go out.

Guided Fault Finding Test Plans Available
- Measuring Value Blocks
- Coding the Tire Pressure Monitoring Control Module -J502-.
- Checking adaptation values for specified pressures.
- System switched OFF.
- Radio interference.
- CAN Bus malfunction.

Determining Sensor Location
- Adjust each tire to different pressure setting and record the setting (i.e. LF 2.3bar (33 psi), RF 2.8bar (41 psi), LR 3.3bar (48 psi), RR 3.8bar (55 psi).

- Using VAS 5051/5052 diagnostic tool and Guided Fault Finding, select Function Test, Reading Measured Values, and view the pressures for all four tires.

Tip:
Guided Fault Finding displays all four tires simultaneous.

Match the pressure to the wheel to determine location.

Sensor Removing and Installation

Tip:
Care must be taken not to damage the sensor(s) during tire mounting and dismounting.

DO NOT use tire lube around sensor area.

DO NOT use tire sealer in tire with sensor.

For sensor replacement, see Repair Manual Group 44, Tire Pressure monitoring, servicing.

Warranty
- Information only.

Required Parts and Tools
- No Special Tools required.
- No Special Parts required. Always see ETKA for the latest part(s) information.