Most Jeep vehicles are equipped with Tire Pressure Monitoring System (TPMS) for the purpose of warning the driver when one or more of the tires are significantly under-inflated, creating a potentially unsafe driving condition. In this article we discuss the reasons for low tire pressure warning light and error message “tire pressure unavailable” in Jeep vehicles.
The tire pressure unavailable warning message appears in Jeep due to a TPMS system fault. When a system fault is detected, the TPMS Warning Light 
will flash on and off for 75 seconds and then remain on solid. The system fault will also sound a chime. In addition, the instrument cluster will display a “SERVICE TIRE PRESSURE SYSTEM” message for a minimum of five seconds and then display dashes (- -) in place of the pressure value to indicate which sensor is not being received.
If the ignition is cycled, this sequence will repeat, providing the system fault still exists. If the system fault no longer exists, the TPMS Warning Light will no longer flash, and the “SERVICE TIRE PRESSURE SYSTEM” message will no longer display, and a pressure value will display in place of the dashes.
A system fault can occur due to any of the following:
- Jamming due to electronic devices or driving next to facilities emitting the same radio frequencies as the TPMS sensors.
- Installing some form of aftermarket window tinting that affects radio wave signals.
- Lots of snow or ice around the wheels or wheel housings.
- Using tire chains on the vehicle.
- Using wheels/tires not equipped with TPMS sensors.
- All four TPMS sensors installed are incompatible or defective.
- Dead batteries inside all four sensors. TPMS batteries usually last 5-10 years and don’t die all at once.
- TPMS receiver module malfunction (rare).
The tire pressure unavailable error message may also appear after rotating or changing tires. The message will disappear and the low tire pressure warning light will turn off when the vehicle is driven at speeds above 15 mph (24 km/h) for up to 20 minutes.
Caution!
- The TPMS has been optimized for the original equipment tires and wheels. TPMS pressures and warning have been established for the tire size equipped on your vehicle. Undesirable system operation or sensor damage may result when using replacement equipment that is not of the same size, type, and/or style. The TPMS sensor is not designed for use on aftermarket wheels, and may contribute to a poor overall system performance. Customers are encouraged to use OEM wheels to ensure TPMS feature operation.
- Using aftermarket tire sealants may cause the Tire Pressure Monitoring System (TPMS) sensor to become inoperable. After using an aftermarket tire sealant it is recommended that you take your vehicle to an authorized dealer to have your sensor function checked.
- After inspecting or adjusting the tire pressure always reinstall the valve stem cap. This will prevent moisture and dirt from entering the valve stem, which could damage the TPMS sensor.
- The TPMS is not intended to replace normal tire care and maintenance, or to provide warning of a tire failure or condition.
- The TPMS should not be used as a tire pressure gauge while adjusting your tire pressure, unless your vehicle is equipped with a Tire Fill Alert (TFA) system.
- Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure. Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle’s handling and stopping ability.
- The TPMS is not a substitute for proper tire maintenance, and it is the driver’s responsibility to maintain correct tire pressure using an accurate tire pressure gauge, even if underinflation has not reached the level to trigger illumination of the TPMS Warning Light.
- Seasonal temperature changes will affect tire pressure, and the TPMS will monitor the actual tire pressure in the tire.
Use OBD2 scanner for diagnosis
Since Jeep vehicles are equipped with on-board diagnostics (OBD), a fault diagnosis can provide initial indications of where the malfunction is located. But when it comes to TPMS, a basic code reader will not suffice. You will need an advanced scanner to monitor TPMS data or read TPMS codes.
BlueDriver is a commonly used scanner by DIYers that can read TPMS codes for most vehicles and isn’t too expensive – costs about a hundred bucks. You can also clear the TPMS fault codes with this device which will turn off the warning light, but the light may come back on if the on-board diagnostic system detects a fault again.
