What is the TPM malfunction on a car?
A TPM malfunction in a car refers to a fault in the Tire Pressure Monitoring System (TPMS), which can trigger a warning light or produce inaccurate tire-pressure readings.
There are two main approaches to tire pressure monitoring—direct TPMS, which uses sensors inside each tire, and indirect TPMS, which relies on wheel-speed data from the ABS system. Malfunctions can arise from equipment, wiring, or software issues, especially after tire service or wheel changes. This article explains what a TPMS malfunction is, how to recognize it, why it happens, and how to address it safely.
What TPMS is and how it works
The Tire Pressure Monitoring System is designed to alert drivers when a tire’s air pressure falls outside the recommended range. There are two basic types:
Direct TPMS
Direct TPMS uses sensors mounted in each tire to measure actual pressure and temperature and transmits the data to the car’s TPMS control module. These sensors are powered by small batteries and typically require sensor replacement when the battery dies or the sensor is damaged.
Indirect TPMS
Indirect TPMS does not use individual tire sensors. Instead, it estimates pressure by comparing wheel-speed data from ABS/ESP sensors. It can misread if calibration is off or if tire sizes differ significantly, and it may require software updates or calibration rather than sensor replacement.
Signs of a malfunction
If you suspect a problem, note common indicators that the system isn’t behaving properly:
- The TPMS warning light stays on, or blinks, even when tires are correctly inflated.
- Inconsistent or inconsistent-looking tire-pressure readings across tires.
- Warning occurs after tire changes, rotations, or wheel-work without a relearn procedure.
- Tire pressures read low or high on the gauge, but you confirm they’re at the recommended level with a wrench or gauge.
- TPMS indicators reset improperly after inflating tires or fail to reset after service.
In short, any persistent discrepancy between actual tire pressures and the TPMS readings, or a warning light that won’t clear after inflating tires, should prompt a system check.
Common causes of TPMS malfunctions
- Dead or weak TPMS sensor batteries in direct-sensing systems.
- Damaged, corroded, or mis-seated sensors, valve stems, or wheel electronics.
- Tires changed or replaced without re-learn of the TPMS sensors’ IDs.
- Faulty TPMS control module or receiver hardware.
- Indirect TPMS calibration issues or software/firmware glitches in the vehicle’s ECU.
- Tire leaks, improper seating of sensors, or extreme temperature exposure affecting readings.
These factors can individually or collectively trigger a malfunction message or unreliable readings.
Diagnosis and repair options
Technicians use a mix of diagnostic tools and procedures to determine the root cause and fix the system:
- Read TPMS fault codes with a specialized scan tool to identify failing sensors or module issues.
- Verify tire pressures with a reliable gauge and compare against the vehicle’s recommended PSI, then inflate as needed.
- Perform a relearn or reset procedure after tire service or sensor replacement, as required by the vehicle make/model.
- Replace faulty direct TPMS sensors or related hardware if the fault is sensor- or battery-related.
- Calibrate or update indirect TPMS software or perform ABS/ESP sensor checks if the issue is miscalibration.
- Inspect for leaks or damaged valve stems and address leaks or seal issues.
After repairs, most vehicles require a driving period or a dedicated relearn process to restore accurate readings.
Costs and maintenance tips
Costs vary depending on the system and the vehicle, as well as where you go for service. Here are typical considerations:
- Direct TPMS sensor replacement in a tire can cost roughly $50–$100 per sensor, plus labor. Entire sensor sets for four wheels can be substantially higher if multiple sensors need replacement.
- Relearn procedures or programming may add service time and cost, especially if a dealer-level tool is required.
- Indirect TPMS solutions generally involve fewer hardware costs and focus on calibration or software updates, which may be cheaper but still require professional service on many vehicles.
To reduce the chance of future malfunctions, practice regular maintenance and careful tire service practices. Many issues arise from improper tire rotation, installation, or failure to perform a relearn after sensor work.
Summary
TPMS malfunctions signal a fault in the tire-pressure monitoring system, either in a direct sensor network or an indirect, software-driven approach. Symptoms range from warning lights and inconsistent readings to miscalibration after tire work. Causes include dead sensors, damaged hardware, improper relearns, and calibration or software faults. Diagnosis typically involves a combination of tire pressure checks, fault-code reading, and subsystem recalibration. Repairs can range from sensor replacement to software updates and require professional service in many cases. Maintaining proper tire pressure and ensuring timely TPMS maintenance helps protect safety and fuel efficiency.
