Tyre Pressure Low: Diagnosis and Fix in Mercedes-Benz E Class W213
The Tyre Pressure Low warning is a common issue in modern vehicles equipped with a Tire Pressure Monitoring System (TPMS). This feature ensures optimal tyre pressure for improved fuel efficiency, better handling, and overall road safety. In this case study, we analyze a Mercedes-Benz E Class W213, where the driver experienced a persistent Tyre Pressure Low warning, despite maintaining correct tyre pressure levels.
This article will cover:
- Diagnostic steps using Mercedes-Benz diagnostic tools
- Identifying faulty TPMS sensors
- Replacing and reprogramming sensors using the Teach-In process
- Ensuring the issue is permanently resolved
Customer Complaint: Tyre Pressure Low Warning in E Class W213
A Mercedes-Benz E Class W213 was brought to the workshop with the Tyre Pressure Low warning sign illuminated on the dashboard. The customer mentioned that they had recently inflated all tyres to the correct pressure, but the warning persisted.
Initial Inspection
- Checked tyre pressure manually using a calibrated gauge – all four tyres had the correct PSI level.
- No visible tyre damage, leaks, or punctures.
- The warning sign was still active, indicating a possible TPMS sensor issue.
To determine the root cause, we proceeded with an in-depth diagnostic check.
Step 1: Running a Short Test
A short test was performed using the Mercedes-Benz XENTRY Diagnosis System to scan for TPMS-related fault codes. The system detected faults in the front tyre pressure sensors, suggesting that they were either malfunctioning or had lost communication with the vehicle’s TPMS control module.
Step 2: Checking Actual Values in the TPMS System
The Actual Values were retrieved using the diagnostic system. This allowed us to examine real-time tyre pressure and temperature data from each TPMS sensor.
Findings from Actual Values:
- Left front and right front TPMS sensors were not transmitting data.
- Rear sensors were functioning normally.
- No immediate connection issue with the TPMS control module.
At this point, we suspected the front tyre pressure sensors were faulty and proceeded with further testing.
Step 3: Testing with Mercedes-Benz Tire Pressure Monitoring System Tool
To confirm the issue, we used a Mercedes-Benz Tire Pressure Monitoring System (TPMS) Tool to individually scan each tyre’s TPMS sensor.
- Left Front Sensor – No response
- Right Front Sensor – No response
- Rear Sensors – Working properly
Since the two front sensors failed to communicate, we concluded that they were defective and needed replacement.
Step 4: Replacing the Faulty TPMS Sensors
The next step was to replace the defective sensors with genuine Mercedes-Benz TPMS sensors. Here’s the procedure:
- Deflate the tyres and carefully remove them from the rims.
- Uninstall the faulty TPMS sensors from the wheel assembly.
- Install the new OEM TPMS sensors, ensuring proper alignment.
- Reinflate the tyres to the manufacturer’s recommended pressure.
- Reinstall the tyres on the vehicle.
After replacing the sensors, the system required reprogramming, also known as the Teach-In process.
Step 5: Performing the TPMS Teach-In Process
To allow the car’s TPMS system to recognize the new sensors, we performed a Teach-In process using the Mercedes-Benz XENTRY system.
Teach-In Procedure:
- Access the TPMS menu in the XENTRY diagnostic system.
- Select the Teach-In process for the new sensors.
- Start the car and drive it above 25 km/h for 10-15 minutes to allow the TPMS module to learn the new sensors.
- Verify that the Tyre Pressure Low warning disappears.
Outcome: The system successfully recognized the new sensors, and the warning light turned off.
Final Check and Test Drive
After replacing and programming the TPMS sensors:
- The Tyre Pressure Low warning was cleared.
- All sensors displayed correct tyre pressure values in the instrument cluster.
- A test drive confirmed the TPMS system was functioning normally.
The issue was completely resolved, and the customer left satisfied with their Mercedes-Benz E Class W213 back to normal condition.
Can You Drive on Low Tyre Pressure?
Driving on low tyre pressure can be extremely dangerous and should be avoided. Low tyre pressure affects vehicle handling, braking performance, and fuel efficiency. Here’s why you should always address this issue promptly:
Risks of Driving on Low Tyre Pressure:
- Increased tyre wear – Low pressure causes uneven tread wear, reducing tyre lifespan.
- Reduced fuel efficiency – Underinflated tyres create more rolling resistance, increasing fuel consumption.
- Poor handling and stability – Lower pressure makes steering less responsive and can cause a loss of control.
- Higher risk of tyre blowouts – Underinflated tyres generate excessive heat, leading to potential tyre failure at high speeds.
Solution: If you notice a Tyre Pressure Low warning, check your tyre pressure immediately and refill to the recommended PSI. If the warning persists, follow the diagnostic steps outlined in this guide.
What Do I Do If Tire Pressure Is Low?
If your tyre pressure is low, follow these steps to restore it to the correct level:
- Check the pressure using a reliable tyre pressure gauge.
- Inflate the tyres to the manufacturer’s recommended PSI, found in the owner’s manual or on the driver’s side door frame sticker.
- Inspect for leaks by looking for punctures, cuts, or slow air leaks.
- Monitor the TPMS warning light – if it remains on after inflation, there may be a sensor issue.
- Visit a professional if the pressure drops frequently, as it may indicate a damaged tyre or a faulty TPMS sensor.
By taking these steps, you can ensure safe driving conditions and prevent further tyre-related issues.
Conclusion: Preventive Measures & Key Takeaways
To avoid Tyre Pressure Low warnings due to TPMS sensor failure, here are some preventive tips:
- Check tyre pressure monthly to ensure correct PSI levels.
- Replace TPMS sensors every 5-7 years, as their internal batteries degrade over time.
- Use only OEM TPMS sensors to ensure compatibility with the Mercedes-Benz system.
- If the Tyre Pressure Low warning persists, run a short test and check Actual Values in the TPMS system.
- Always perform a Teach-In process after sensor replacement to sync the new sensors with the TPMS module.
By following these steps, Mercedes-Benz E Class W213 owners can effectively diagnose and resolve TPMS issues, ensuring a safer and more efficient driving experience.
