A. Low Tire Pressure Warning Light ON

a. Low Tire Pressure Warning Light ON - Low Tire Pressure





The low tire pressure warning light will illuminate when there is a significant low-pressure condition within a tire, or if a rapid loss of air pressure is detected. There are a number of environmental factors that can affect the tire pressure, and therefore potentially illuminate a low pressure warning light.

The main two environmental factors are air temperature and location elevation. Colder air will reduce tire pressure, while hotter air will increase tire pressure. High elevation may also increase tire pressure.

If a customer comments that the TPMS (Tire Pressure Monitoring System) tire pressure warning lamp is "ON" for the first few miles of driving after a cold start or stays "ON" continuously, particularly in cold ambient temperatures, please be sure to inform the customer that the system is operating correctly to warn of a low tire pressure condition, and a system diagnosis may not be required. The customer should be made aware of the following:

^ This condition may be caused by low tire pressure if the tire pressure falls below the low warning threshold for any reason including low temperature.

NOTE:
For vehicles equipped with the TPMS, the threshold pressure limit is 25% below the vehicle's recommended cold tire pressure, shown on the placard located on the driver side B-pillar.

^ Recommend that the customer inflate tires when they are cold or compensate for being hot by inflating the tire to a pressure to 3 or 4 psi above specification.

^ Tire pressures should be checked after traveling between areas at significantly different elevations. Adjust tire pressures accordingly.

IMPORTANT:
Tire pressure must be set at the specification found on the placard located on the driver side B-pillar when the tires are COLD.

NOTE:
The tire pressure will vary with temperature by approximately 1 psi (6.9 kPa) for every 12°F (6.5°C).

^ Recommend that the customer check and adjust all tire pressures, including the spare tire, once a month. (For additional information, suggest that the customer refer to the vehicle owner's manual).

NOTE:
Adjusting the tire air pressure is included in the PDI process and is not covered under normal warranty. Tire air pressure adjustment is a normal maintenance item.

NOTE:
If you need to verify that your dealership air pressure gauge matches the TPMS sensor air pressure readings, you can use the "Current Data" mode on the TPMS checker to read the current pressure in a tire. Then read the tire pressure with your gauge. The readings should be within 2 psi. If not, calibrate or replace the gauge. Another potential reason for a reading difference is elevation. Repeat for all gauges normally used during PDI.