Quick answer

A TPMS fault warning usually means the monitoring system can’t get reliable data from one or more sensors. Common causes include a low sensor battery, a sensor not paired to the correct wheel position, signal drop-outs (especially when towing), or a sensor that has been damaged or removed.

TPMS fault vs tyre pressure warning: what’s the difference?

• Tyre pressure warning: the system is reading pressure data and it’s outside your safe thresholds (low or high PSI).
• TPMS fault warning: the system is not reading data properly from a sensor or the system itself has an error.

If your warning happens only at speed, this page may also help: Why Does My TPMS Go Off on the Highway?

Common TPMS fault warnings and what they usually mean

1) “TPMS Fault” or “System Fault”

This usually indicates a communication or system error. The receiver may not be picking up the sensor signals consistently.

• Possible cause: sensor not transmitting or receiver not receiving
• Possible cause: sensor battery low
• Possible cause: pairing/configuration issue

2) “Sensor Fault” or “Sensor Error”

Usually means a specific sensor is not responding or sending valid data.

• Possible cause: sensor battery depleted
• Possible cause: sensor damaged (impact, corrosion, water ingress)
• Possible cause: sensor fitted incorrectly or valve stem issue

3) “No Signal” or “Signal Lost”

Means the receiver has stopped receiving data from one sensor. If you tow, signal loss can occur if the system is not designed for towing range or if a repeater is required.

Towing advice: Best TPMS for Caravans & Towing

4) “Low Battery”

Many external TPMS sensors use a replaceable battery. A low battery warning often comes before “no signal”. Replace the battery and re-check sensor pairing.

5) “Check TPMS” after tyre rotation or replacement

If tyres have been rotated, replaced, or moved between axles, the TPMS may still be expecting each sensor to be in the old position. Relearn or re-pair sensors to the correct wheel locations.

What to do when you see a TPMS fault warning (step-by-step)

Step 1: Check whether it’s a pressure warning or a fault

Look at the screen/app. If you can still see PSI readings, it may not be a system fault. If one tyre shows “—”, “no signal”, or blank data, it’s likely a fault or communication issue.

Step 2: Check tyre pressures manually

Even if it appears to be a fault, confirm tyre pressures with a quality manual gauge. Safety first.

Step 3: Identify which tyre/sensor is affected

Most systems show which wheel position is missing data. Note the tyre and sensor.

Step 4: Inspect the sensor and valve stem

• Is the sensor fitted tightly (not overtightened)?
• Is there any visible damage or corrosion?
• Is the valve stem cracked or leaking?

Step 5: Replace the sensor battery (if external sensor)

If your system uses replaceable batteries, a battery change often resolves faults. After replacement, re-check readings.

Step 6: Re-pair / relearn the sensor

If the sensor was moved, or the receiver is confused about wheel position, use pairing mode to reassign it correctly.

Step 7: Reset the receiver (if required)

Some systems need a reset after changes. Follow your manual and re-check readings after driving for a few minutes.

If your sensor still isn’t reporting, this page helps: TPMS Sensor Not Reading? Here’s Why

TPMS faults when towing: common causes

Towing adds distance and interference between the receiver and the caravan sensors. If your fault warning happens mainly while towing:

• Signal range may not be sufficient for your rig length
• Sensor placement may be shielded by the caravan body or load
• A signal repeater may be required (system dependent)
• Sensor batteries may be weak and struggling at distance

For towing setup guidance: Best TPMS for Caravans & Towing

When should you stop driving?

Stop safely and check your tyres immediately if:

• You feel vibration, pulling, or handling changes
• You smell rubber, feel heat near a wheel, or see smoke
• A pressure reading drops rapidly (not just a fault message)
• A temperature reading rises quickly and keeps rising

A TPMS fault message alone doesn’t always mean immediate danger, but it does mean you’re flying with less information. Confirm tyre pressures manually as soon as practical.

How to reduce TPMS fault warnings

• Set correct baseline pressures before long trips
• Replace sensor batteries proactively if readings become unstable
• Re-pair sensors after tyre rotations or replacements
• Use a towing-ready system if monitoring a caravan
• Inspect valve stems regularly

If you’re installing from scratch: How to Install a TPMS

Need a TPMS that makes warnings clear?

A good TPMS should make it obvious whether you’re seeing a true tyre issue or a sensor communication problem.

View the Safety Sam system here: Tyre Pressure Monitoring System

FAQs

Can a TPMS fault warning be caused by low tyre pressure?

Usually no. Low tyre pressure typically triggers a pressure warning, not a system fault. A fault warning usually relates to sensor or communication issues.

Why does my TPMS say “no signal” for one tyre?

The sensor may have a low battery, be damaged, be incorrectly paired, or be out of range (especially when towing).

Will replacing the sensor battery fix a TPMS fault?

If you use external sensors with replaceable batteries, yes, battery replacement often fixes faults. If the sensor is sealed or damaged, it may need replacement.