A customer reports that the low tire pressure warning light (TPMS) illuminates intermittently, specifically after driving for about 15-20 minutes on the highway. All tire pressures have been manually checked and are correct. A scan tool reveals no active or stored TPMS DTCs. Which of the following is the MOST likely cause?
- AA calibration issue with the TPMS system
- BAn internal fault within the instrument cluster
- CA low battery in one of the tire pressure sensors
- DA faulty TPMS control module
Show answer & explanationAnswer & explanation
Correct answer: C. A low battery in one of the tire pressure sensors
TPMS sensors are battery-powered, and as batteries age, their voltage can drop. This drop is often exacerbated by increased signal transmission required at highway speeds or by temperature changes after driving. An intermittent warning without stored codes and correct tire pressure strongly points to a weak sensor battery struggling to transmit reliably, which may not trigger a hard fault immediately.
Why the other options are wrong
- A. A calibration issue would typically cause a persistent incorrect reading or a light that comes on consistently, not intermittently after a specific driving pattern.
- B. An instrument cluster fault would be less likely to be triggered by driving conditions and more likely to affect other warning lights or gauges.
- D. A faulty TPMS control module would likely cause more consistent errors or a complete system failure, often with specific DTCs.
TPMS Sensor Battery Life
Tire Pressure Monitoring System (TPMS) sensors contain small batteries that have a finite lifespan (typically 5-10 years). As batteries weaken, they can cause intermittent communication issues and false warnings.
- Battery life is influenced by temperature, usage, and age.
- Weak batteries often lead to intermittent warnings before complete failure.
- Replacement usually involves replacing the entire sensor.
Memory trick: Highway light, no codes in sight? Sensor's battery's losing its might!