TPMS Sensor

Replace a TPMS (Tire Pressure Monitoring System) sensor on a 2019 Mercedes-Benz G-Class, including wheel removal, tire dismount/mount, sensor replacement, and system relearn.

Warnings

Tools required

Parts

• TPMS sensor (433 MHz Mercedes-Benz compatible) × 1 — A0009050030 or equivalent
• TPMS valve stem seal/grommet × 1 — Included with sensor or A0009056200
• TPMS valve core × 1 — Use OEM specification
• Tire bead lubricant × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake.
2. Place wheel chocks behind wheels that will remain on the ground.
3. Identify which wheel has the faulty TPMS sensor using diagnostic tool or by symptom (TPMS warning light, specific tire reading missing).
4. Loosen wheel lug nuts on the affected wheel 1/4 turn while vehicle is on ground.
5. Raise vehicle using floor jack at appropriate jacking point and secure with jack stands.
6. Ensure tire changer machine is clean and properly lubricated to avoid damaging the new sensor during installation.

Procedure

1. 1

   Remove wheel from vehicle
   Remove all wheel bolts from the affected wheel. Carefully pull the wheel off the hub and place it on a clean surface near the tire changer machine. Inspect the wheel for damage or corrosion around the valve stem area.
2. 2

   Deflate tire completely
   Use valve core removal tool to remove the valve core from the TPMS sensor. Allow tire to deflate completely. Inspect the valve stem and note the sensor orientation relative to the wheel before disassembly.
3. 3

   Break tire bead
   Position wheel on tire changer machine. Use bead breaker to break both inner and outer tire beads from the wheel rim. Work carefully around the area opposite the TPMS sensor first, then approach the sensor area with caution to avoid striking it.
4. 4

   Demount tire from wheel
   Use tire changer machine to demount the tire from the wheel. Keep the machine's demount head away from the TPMS sensor location during initial bead lift. Rotate the wheel so the sensor is in the safe zone (opposite the demount head) throughout the process.
5. 5

   Remove failed TPMS sensor
   Locate the TPMS sensor mounted to the wheel valve stem hole. Remove the single retaining nut securing the sensor to the wheel using a TPMS socket or appropriate tool. Pull the sensor and valve stem assembly out through the wheel drop center. Inspect the valve stem hole for corrosion or damage.
6. 6

   Prepare new TPMS sensor
   Unpack the new TPMS sensor and verify it is the correct 433 MHz frequency for Mercedes-Benz. Install the new valve stem grommet/seal onto the sensor valve body. Ensure the seal is seated properly in the sensor groove. Install a new valve core finger-tight into the sensor valve stem.
7. 7

   Install new TPMS sensor
   Insert the new TPMS sensor assembly through the wheel drop center and position the valve stem through the valve stem hole from inside the wheel. Ensure the sensor body is oriented correctly (battery side facing outward). Thread the retaining nut onto the valve stem and hand-tighten. Using a calibrated TPMS torque wrench, tighten the nut to the manufacturer-specified torque (verify exact value from the sensor/Mercedes-Benz spec, typically ~8 Nm for clamp-in sensors). Do not exceed the specified torque value.
   Torque spec

   TPMS Sensor Nut7 Nm (5 lb-ft)
8. 8

   Mount tire onto wheel
   Apply tire bead lubricant to both tire beads. Position the tire onto the wheel with proper directional orientation if applicable. Use tire changer machine to mount the tire, ensuring the machine's mount head stays clear of the TPMS sensor location. Seat both beads fully onto the rim.
9. 9

   Inflate and balance tire
   Inflate the tire to the recommended pressure (check door jamb placard, typically 35-40 psi for G-Class). Verify the tire bead is fully seated on both sides. Balance the wheel assembly on a wheel balancer, taking care not to place balancer cones or clamps near the TPMS sensor.
10. 10

    Reinstall wheel on vehicle
    Lift the wheel assembly and position it onto the hub. Thread all wheel bolts by hand to prevent cross-threading. Lower the vehicle until the tire just touches the ground (wheel cannot rotate). Torque all wheel bolts to the Mercedes-Benz specification (approximately 150 Nm / 110 lb-ft — verify for the specific wheel/VIN) in a star pattern. Fully lower the vehicle and remove jack stands.
    Torque spec

    Wheel Lug Nuts142.4 Nm (105 lb-ft)
11. 11

    Program TPMS sensor to vehicle
    Connect Mercedes-Benz Xentry diagnostic tool or equivalent to the vehicle OBD-II port. Navigate to TPMS programming function. Follow the tool's prompts to teach the new sensor ID to the vehicle's TPMS control module. This requires entering the sensor's unique ID or using the tool's auto-learn trigger function. Complete the programming cycle and verify the new sensor is recognized by the system.

Reassembly

1. Reassembly is integrated into the procedure steps above.
2. Ensure tire pressure in all four tires matches the vehicle's door jamb specification before finalizing the TPMS relearn process.

Verification

• Start the vehicle and verify the TPMS warning light extinguishes after a few seconds of driving.
• Using the diagnostic tool, verify all four TPMS sensors are transmitting and showing correct pressure readings.
• Check the instrument cluster TPMS display to confirm all tire pressures are displayed correctly.
• Drive the vehicle for 5-10 minutes at speeds above 15 mph to ensure the TPMS system fully initializes the new sensor.
• Verify no air leaks are present at the valve stem by applying soapy water and checking for bubbles.

More procedures for this vehicle