TPMS Warning Light On? How to Diagnose & Reset Tyre Pressure Sensors with a Scan Tool

Introduction

That yellow tyre pressure warning light can mean anything from a slightly flat tyre to a dead sensor. Most workshops and confident DIYers can resolve TPMS issues in minutes — if they have the right scan tool. Here's exactly what to do.

What is TPMS and why does it trigger?

Tyre Pressure Monitoring Systems (TPMS) became mandatory on new vehicles from around 2008 onward. Each wheel houses a sensor that broadcasts pressure and temperature data to the vehicle's ECU. The warning light triggers when:

• A tyre is 25% or more below the recommended pressure
• A sensor battery has died (typical lifespan: 5–10 years)
• A sensor is faulty or was replaced without being registered to the vehicle
• The system lost communication with one or more sensors

Step 1 — Read the TPMS fault codes

Connect your scan tool to the OBD-II port and navigate to TPMS or Chassis > TYRE system. A capable tool like the XTOOL XT70W or XTOOL XT80W will display live sensor data (pressure, temperature, battery status) and any stored fault codes for each wheel position.

Common codes to look for:

• C0750–C0760 range — wheel speed/sensor signal faults
• Manufacturer-specific TPMS codes (U-codes for communication loss)

Step 2 — Identify the faulty sensor

Live data will show which sensor (FL, FR, RL, RR) is missing or reading incorrectly. A missing ID usually means a dead battery or physical damage. An incorrect reading suggests a slow leak or a faulty sensor.

Step 3 — Fix the underlying issue first

• Inflate tyres to manufacturer spec (found on the door sill sticker)
• Replace faulty sensors if battery or physical damage is confirmed

Step 4 — Reset / relearn the TPMS system

After correcting the issue, you need to register the sensors to the ECU. Your scan tool's TPMS relearn function handles this. On tools like the LAUNCH X431 PROS Elite, navigate to Special Functions > TPMS Reset and follow the on-screen relearn procedure — stationary or drive-cycle, depending on the vehicle.

Choosing the right tool for TPMS work

For workshops doing regular TPMS resets, a professional bi-directional scanner with special functions access is essential. For DIY use, the XTOOL Anyscan A30X covers TPMS reads and basic resets at an accessible price point.

Conclusion

TPMS diagnostics are a quick win for any workshop or serious DIYer. A capable scan tool turns a frustrating warning light into a 10-minute job.