2017 Subaru Outback TPMS Light Flashes Then Stays On: Fix Guide

That flashing TPMS light for a minute, then steady, means the system isn't seeing one or more sensors — not just low tire pressure. Most likely, you've got a dead TPMS sensor battery or a sensor that's not communicating. Less common, but possible, is a fault in the TPMS control module or wiring.

If you just had tires replaced or rotated, sometimes the shop didn't relearn the sensors. If not, it's usually a sensor gone bad.

Most likely culprits

• TPMS sensor failure — Sensor battery dead or sensor not transmitting; typical after 5-7 years.
• TPMS control module issue — Rare, but possible if all sensors check out and module won't communicate.
• Sensor registration/relearn not performed — If tires/wheels were changed or rotated and sensors weren't relearned.

How to narrow it down

1. Check tire pressures — Make sure all four tires are at spec. If low, fill and see if light changes. If not, move to step 2.
2. Scan TPMS system with a capable tool — Look for sensor IDs, battery status, and any codes. If one or more sensors aren't reporting, that's your culprit.
3. Use a TPMS activation tool — Walk around the car and trigger each sensor. If one doesn't respond, it's dead or not registered.
4. Check sensor registration — If you recently changed tires/wheels, verify all sensors are registered to the car.
5. Inspect for aftermarket wheels or sensors — If you have aftermarket wheels, make sure compatible sensors are installed.
6. If all sensors respond and are registered, but light stays on — Suspect TPMS module or wiring fault.

Possible parts (if needed)

• TPMS sensor (if scan/activation tool shows one or more not responding)
• TPMS control module (only if all sensors are good and module won't communicate)

A few questions

• Did you recently replace or rotate tires, or install aftermarket wheels?
• Has the TPMS light been on for a while, or did it just start after a service?
• Are you able to access a scan tool that can read TPMS sensor data?

Let me know what you find on the scan or activation tool — that's the fastest way to confirm which sensor is bad. If you can't scan, most tire shops can check sensors for you.