Hyundai Elantra AD: Tire Pressure Monitoring System

Sixth generation (AD; 2017–2020) / Hyundai Elantra AD 2017-2020 Service Manual / Suspension System / Tire Pressure Monitoring System

Components and Components Location

Components

1. Body control module(BCM)
2. TPMS sensor (FL)
3. TPMS sensor (RL)

4. TPMS sensor (FR)
5. TPMS sensor (RR)

Description and Operation

Description

TREAD Lamp

-	Tire Under Inflation / Leak Warning.

Turn on condition

A.	When tire pressure is below allowed threshold

B.	When rapid leak is detected by the sensor.

C.	Indicates that tire needs to be re-inflated to placard pressure / repaired.

Turn off condition

A.	Under-inflation ; When tire pressure is above (warning threshold + hysteresis).

B.	Rapid Leak ; When tire pressure is above (leak warning threshold).

DTC Warning

Turn on condition

A.	When the system detects a fault that is external to the receiver/ sensor.

B.	When the system detects a receiver fault.

C.	When the system detects a sensor fault.

Turn off condition

If the fault is considered as 'critical', then the lamp is held on throughout the current Ignition cycle (even if the DTC has been demoted). This is because it is important to bring the problem to the drivers attention. On the following Ignition cycle, the demotion conditions will be re-checked. If the demotion conditions occur, the lamp will be turned off. It will be held on until DTC demotion checking is completed.

B.	'Non critical' faults are those that can occur temporarily e.g. vehicle battery under voltage. The lamp is therefore turned off when the DTC demotion condition occurs.

System Fault

General Function

A.	The system monitors a number of inputs across time in order to determine that a fault exists.

B.	Faults are prioritized according to which has the most likely cause.

C.	Maximum fault store is equal to 15.

D.	Certain faults are not covered through DTC. The main ones are :

1)	Sensor thermal shutdown (over 257 °F/ 125 °C).

2)	Ignition Line stuck ; requires observation of lamps at Ignition ON to diagnose.

TPMS Sensor Description and Operation

Description

General description

WU is a sensor placed in the tire that reports pressure and temperature.

The WU is mounted inside the wheels, fixed to the valve. The angle between the valve and the housing of the WU is variable.

This allows adaptation to various types of rims.

The Wheel Unit is made of a PCB supporting the electronic hardware and encapsulated inside a housing which is potted with polyurethane.

It is self-powered by a battery and includes all systems for parameter measurement (pressure, temperature and centrifugal acceleration and optionally rotation direction), RF transmission and LF detection.

To achieve the specified battery lifetime, the WU supports various measurement and transmission timings, depending on WU operation mode.

For RF transmission, WU uses an internal antenna.

2.	First Block Mode : When vehicle start driving, Sensor enter Mode First Block. Typical period of RF emissions is 16 sec. for 40 times for Auto-learning and Auto-location function.

3.	Driving Mode : After 19 min. parking and then finishing Mode First Block mode, WU enter Driving mode. Typical period of RF emissions are 64 sec above 4g vehicle speed.

4.	Parking Mode : at below 3g Vehicle speed, enter Parking mode. Typical periodicities of RF emissions are 13 hours.

TPMS Sensor Repair procedures

Removal

1.	Remove the valve core and deflate the tire.

Remove the side of the tire bead area from the wheel using tire changing machine .

•	The tire bead should be broken approx. 90° from the valve side of the wheel. The bead breaker should not be set too deep.

•	Avoid tire/tool contact with the valve on dismount.

•	Dismount should end near the valve.

3.	Rotate the wheel clockwise.

4.	The valve during transportation (air inlet portion of the silver) deviated from its original location be sure to check whether the original position of the valve (metal brackets) are assembled in indented state.

5.	While tightening the nut on the valve as not to deviate from the fixed position while rotating the valve to a fixed location (metal brackets to fit inside) and push. The specified torque (8Nm) to tighten the nut does not reuse.

6.	Contact with the rim so that the valve washer seals the valve hole put into.

7.	Housing with two fingers holding the valve in the axial direction with one finger and push the valve.

8.	Housing, the state must be visible laser marking.

9.	When the valve is fully inserted so that the contact between the sensor and the rim while keeping hands on the wheel nut tightening will start Wed.

10.	While maintaining the position of the valve and the sensor is mounted nut.

11.	Apply tire soap or lubrication to the top and bottom tire beads.

12.	To fit the bottom bead, position the sensor at the 5 o’clock position relative to the head on the tire changing machine

13.	Place the tire on the rim so the bottom bead touches the edge of the rim after the sensor (6 o’clock). Rotate the rim clockwise, and push down on the tire at the 3 o’clock position to fit bottom bead.

14.	After bottom bead is on tire, rotate the rim until the sensor is at the 5 o’clock position relative to the head on the tire changing machine. Push down on the tire at the 3 o’clock position and rotate the rim clockwise to fit the top bead.

15.	Inflate the tire until both beads seat.

16.	In the case of TPMS sensor failure, TPMS sensor needs learning. Faulty sensor is replaced new units, conduct learning of TPMS sensors.

Inspection

After installing TPMS sensor test methods Thai

1.	Sealing washer on the outside rim of hole to be compressed.

2.	The lower part of the valve housing, a fixed place (no metal brackets) should be located.

3.	Housing is at least one or more points on the surface of the rim should contact.

4.	The rim of the housing mounting height shall not exceed the height of the chin. [Normally] [Faulty]

Diagnosis procedure by using diagnostic device

As manual for diagnosis methods by using diagnosis device, the main contents are as follows:

1.	Connect self-diagnosis connector(16pins) located in the lower of driver side crash pad to self-diagnosis device, and then turn the self-diagnosis device after key is ON.

2.	Select the "vehicle model" and "TPMS" on GDS vehicle selection screen, then select OK.

Diagnostic Procedure Using a Diagnostic Instrument

The following section describes how to diagnose faults using a diagnostic instrument.

1.	Connect the diagnostic instrument to the self-diagnostic connector (16-pin) beneath the crash pad on the side of driver's seat, and then turn on the ignition to activate the diagnostic instrument.

In the GDS Vehicle Type Selection menu, select "Vehicle Type" and "TPMS" System, and then opt for "OK."

[Initial Screen for Sensor ID Registration]

[Register Sensor function description]

[Preparation phase sensor measurements]

[Sensor register method 1]

[Sensor register method 2]

[Sensor register method 3]

[Sensor register method 4]

[Sensor register method 5]

•	Make sure that the read ID matches the written ID.

•	After successfully registering the sensor, proceed to "Sensor Wireless Information" to ensure that the sensor functions correctly.

[Sensor Status initialization]

[Sensor function description]

[Preparation phase sensor measurements]

•	In North America, the cable is measured separately.

•	In Domestic/General(European) area, the cable is measured without separation.

[Sensor measurements 1]

[Sensor measurements 2]

[Sensor Status]

•	Check each sensor component to ensure that it functions correctly.

•	Replace any tires or sensors that do not function correctly, proceed to the sensor registration procedure, and check if the sensors function correctly.

TPMS Receiver Description and Operation

Description

TPMS Receiver : BCM(body control module) integrated management

Mode

(1)

Virgin State

A.	The receiver as a sole part is shipped in this state. Replacement parts should therefore arrive in this state.

B.	In this state, there is no Auto-Location, no sensor wake-up, no sensor monitoring and no DTC monitoring.

C.	The state indicates that platform specific parameters must be written to the receiver and that sensors are un-learned.

(2)

Normal State

A.	In order for tire inflation state and DTC monitoring to occur, the receiver must be in this state.

B.	In this state, automatic sensor location / learning is enabled.

Overview

A.	Learn TPMS sensor for under inflation monitoring automatically.

B.	Uses sensor information, distance travelled, background noise levels, Auto-learn status, short / open circuit output status, vehicle battery level, internal receiver states to determine if there is a system or a vehicle fault.

Operation

General Function

A.	Auto-learn takes place only once per Ignition cycle.

B.	On successful completion, 4 road wheel sensor ID's are latched into memory for monitoring.

C.	Until Auto-learn completes, previously learned sensors are monitored for under inflation / leak warnings.

General Conditions to Learn New Sensors :

A.	Receiver must determine that it is confident that sensor is not temporary : a. Uses vehicle speed. b. Uses confidence reduction of previously learned sensors.

B.	Typical time at driving continuously over 15.5 mph(25 kph) to learn a new sensor is up to 20 minutes.

General Conditions to Un-Learn a sensor that is removed :

A.	It takes less than 20 minutes at 15.5 mph(20~30 kph).

B.	Confidence reduction is dependent on time which vehicle is driven at speed greater than or equal to 12.4 mph (20 ~ 30 kph).

TPMS Receiver Repair procedures

Removal

1.	Disconnect the negative (-) battery terminal.

2.	Remove the glove box. (Refer to Body - "Glove Box Upper Cover Assembly")

3.	Remove the smart key unit. (Refer to Body - "Smart Key Unit")

4.	Disconnect the body control module connectors (A).

5.	Remove the body control module (A) after loosening the mounting nuts.

Installation

1.	Install the body control module.

2.	Connect the body control module.

3.	Install the glove box upper cover assembly.

Adjustment

Diagnosis procedure by using diagnostic device

As manual for diagnosis methods by using diagnosis device, the main contents are as follows :

1.	Connect self-diagnosis connector(16pins) located in the lower of driver side crash pad to self-diagnosis device, and then turn the self-diagnosis device after key is ON.

2.	Select the "vehicle model" and "TPMS" on GDS vehicle selection screen, then select OK. [Sensor ID Writing] [Vehicle name input initialization] [VIN input initialization]