Is checking the spare tire in the vehicle a common practice at your shop? If not, it should be added to your TPMS standard operating procedure. It can often be the culprit of wasted time and money when trying to turn out the TPMS light on a vehicle.
We get this call a lot on our tech hotline: “The vehicle TPMS procedure was completed correctly but the light still won’t go out.” Many of these cases can be avoided if the full-sized spare tire is equipped with a sensor during the initial inspection. This often occurs on SUVs, pickups and crossovers where the spare is stored under the vehicle. If this is the case, ensure any TPMS service includes the spare tire from the beginning to save time on the lift. Forgetting to include the spare could lead to these two circumstances:
A solid TPMS light on the dashboard indicates that one or more of the tires are at least 25% below placard pressure. If you go around and fill all of the tires to the recommended placard pressure and the light is still solid, there is a good chance that the vehicle is also detecting the pressure in the spare tire and it is at least 25% below the manufacturer’s recommendation. Fill it up to the correct placard pressure and the light should go out.
If the TPMS light blinks for 30-90 seconds before remaining solid, it indicates that there is something wrong with the actual TPMS system. It could be a dead sensor battery, a broken sensor or the relearn procedure was not properly performed. If you confirm that these situations are not the case and find that the TPMS light is still blinking, check for a full-size spare tire. In some cases, you also need to relearn the spare tire to the vehicle after completing a TPMS service. With the use of a TPMS diagnostic tool you can test the spare tire TPMS sensor to check if the sensor has a dead battery or is damaged.
Some could look at including the spare tire in their shop’s standard operating procedure as wasted time. However, I suggest looking at the spare tire as a solid case for an upsell. If one or more TPMS sensor batteries dies, there is a very good chance the others will soon follow. In the case that a sensor is present and transmitting a signal from the spare tire, that battery will die soon as well. A best practice would be to upsell a full set of five sensors, saving the driver time and money in the long run by completing the entire service in one visit.