Jeep Grand Cherokee low tire pressure warning light causes, how to reset

Jeep Grand Cherokee is 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 the amber colored TPMS warning light in Grand Cherokee, and how you can reset it.

Jeep Grand Cherokee – (photo by Jeep)

The TPMS warning light illuminates in Jeep Grand Cherokee when air pressure is low in one or more of the tires, battery has depleted in a pressure sensor, TPMS receiver module has malfunctioned, or a pressure sensor has been damaged.


Low tire pressure

When the amber colored TPMS warning light turns on in your Grand Cherokee, stop your vehicle when it is safe to do so and check tire pressure on all the wheels, including the spare wheel (if your vehicle has one). Driving on a significantly under-inflated tire causes the tire to overheat and can lead to tire failure.

Reinflate the tires

Reinflate all the tires of your Grand Cherokee to the manufacturer specified air pressure, which is mentioned on the vehicle placard or tire inflation pressure label usually located on the B-pillar or the edge of the driver door.

Resetting the TPMS warning light

After you have inflated all the tires to the correct air pressure, the TPMS warning light will turn off automatically when the vehicle is driven at speeds above 15 mph (24 km/h) for up to 20 minutes. Jeep Grand Cherokee uses the direct method for monitoring tire pressure, which means a pressure sensor actively records the internal pressure and air temperature of the tire on each wheel. There is no need to reinitialize the TPMS system in order to reset the warning light. There is no reset button like the one you see in vehicles with indirect TPMS system which uses ABS sensors to detect low tire pressure.

If the low tire pressure light does not turn off automatically after reinflating the tires in your Grand Cherokee, increase the tire pressure by 5 psi on top of the factory recommended value, and drive your vehicle for at least 10 miles (16 km). After the TPMS warning light turns off, and the vehicle has been parked for a few hours, reduce the tire pressure to the factory recommended value.

Low tire pressure warning in Jeep Grand Cherokee.

Chilly weather can turn on low tire pressure light in Grand Cherokee

Cold weather is one of the most common cause for low tire pressure warning light in Jeep Grand Cherokee. When analyzing WheelsJoint’s statistical data, it has been observed that there is sharp rise in the number of searches for TPMS warning light causes at the start of every winter season, about three times higher as compared to mid summer season.

The air, like most other substances, expands when heated and contracts when cooled. So when the weather gets colder, the tire pressure decreases, which could trigger TPMS warning light in Grand Cherokee. The tire pressure will vary with temperature by about 1 psi (7 kPa) for every 12°F (6.5°C).

Tire pressure vs temperature: This chart shows how tire pressure of 35 psi at temperature of 35°C (95°F) decreases by roughly 1.6 psi with every 10°C (18°F) drop in temperature.

Inflate tires when cold

Tire pressure in Grand Cherokee should always be set based on cold inflation tire pressure. This is defined as the tire pressure after the vehicle has not been driven for at least three hours, or driven less than 1 mile (1.6 km) after a three-hour period.


Do not adjust tire pressure when hot

The tires on your Grand Cherokee can get around 50 degrees hotter than the outside temperature when you’re driving, which increases the tire pressure by about 4 psi – this is normal and there should be no adjustment for this increased pressure.

Does altitude affect tire pressure?

Yes, altitude can change tire pressure values, but it is negligible and not a cause for concern. If you drive your Grand Cherokee from sea level to Mount Evans Scenic Byway in Colorado which is the highest paved road in North America at the altitude of 14,130 feet (4,307 m), the tire pressure should theoretically increase by approximately 6 psi. But, the decrease in ambient temperature at higher elevation contracts the air in tires and compensates for any altitude pressure changes.

Is it safe to drive Grand Cherokee with low tire pressure?

The driving characteristics of Grand Cherokee change even if the air pressure is 5 psi less than manufacturer’s recommended value: the braking distance can be longer, cornering worse, and at particularly high speeds there is even a risk that the tire will burst. Low tire pressure also increases tire wear, and the higher rolling resistance of the tire means higher fuel consumption. So it is recommended to reinflate the tires to the correct pressure as soon as possible.

Dead battery in a tire pressure sensor

Each tire pressure sensor in Grand Cherokee is powered by a built-in lithium-ion battery. When the battery is depleted, the sensor stops transmitting tire pressure information to the receiver module. When this happens, the TPMS warning light will flash every time the engine is started, and will remain illuminated until you turn off the vehicle.

How long do the pressure sensor batteries last?

The tire pressure sensor batteries usually last anywhere from 5 to 10 years in Grand Cherokee. When the battery is depleted, you must replace the sensor itself, as the battery is sealed into the sensor unit and is non-replaceable.

Identifying a faulty pressure sensor

The most reliable method for detecting a faulty tire pressure sensor or a sensor with dead battery is by testing each sensor with a scan tool. For example, MaxiTPMS TS408 is commonly used for diagnosing and programming tire pressure sensors. A sensor that is not detectable by the scanner is most likely defective and should be replaced with a new one.

Scan each wheel with a scan tool like MaxiTPMS TS408 and see which one does not respond.

If you don’t want to spend over a hundred bucks on a scanner, then head over to any reputable tire shop and perform a TPMS diagnostic scan of your Grand Cherokee. Some shops like Discount Tire and Pep Boys offer free of charge TPMS diagnostic services.

Installed new tires?

If a pressure sensor stopped responding after you installed new tires on your Grand Cherokee, it is possible the sensor got damaged during tire installation. These sensors are quite sensitive, and can be easily damaged if utmost care is not taken while changing tires.


Jeep Grand Cherokee TPMS user guide

The TPMS warning light switches on and a message is displayed to indicate that the tire pressure is lower than the recommended value and/or that slow pressure loss is occurring. In these cases, optimal tire duration and fuel consumption may not be guaranteed.

The tire pressure will vary with temperature by about 1 psi (7 kPa) for every 12°F (6.5°C). This means that when the outside temperature decreases, the tire pressure will decrease. Tire pressure should always be set based on cold inflation tire pressure. This is defined as the tire pressure after the vehicle has not been driven for at least three hours, or driven less than 1 mile (1.6 km) after a three-hour period. The tire pressure will also increase as the vehicle is driven — this is normal and there should be no adjustment for this increased pressure.

The TPMS will warn the driver of a low tire pressure if the tire pressure falls below the low pressure warning threshold for any reason, including low temperature effects, or natural pressure loss through the tire.

The TPMS will continue to warn the driver of low tire pressure as long as the condition exists, and will not turn off until the tire pressure is at or above recommended cold tire pressure. Once the low tire pressure warning has been illuminated, the tire pressure must be increased to the recommended cold tire pressure in order for the TPMS Warning Light to be turned off.

When filling warm tires, the tire pressure may need to be increased up to an additional 4 psi (28 kPa) above the recommended cold placard pressure in order to turn the TPMS Warning Light off.

The system will automatically update and the TPMS Warning Light will extinguish once the updated tire pressures have been received. The vehicle may need to be driven for up to 20 minutes above 15 mph (24 km/h) to receive this information.

For example, your vehicle has a recommended cold (parked for more than three hours) tire pressure of 36 psi (248 kPa). If the ambient temperature is 68°F (20°C) and the measured tire pressure is 28 psi (193 kPa), a temperature drop to 20°F (-7°C) will decrease the tire pressure to approximately 24 psi (165 kPa). This tire pressure is sufficiently low enough to turn on the TPMS Warning Light. Driving the vehicle may cause the tire pressure to rise to approximately 28 psi (193 kPa), but the TPMS Warning Light will still be on. In this situation, the TPMS Warning Light will turn off only after the tires have been inflated to the vehicle’s recommended cold tire pressure value.

TPMS system components

The Tire Pressure Monitoring System (TPMS) uses wireless technology with wheel rim-mounted electronic sensors to monitor tire pressure levels. Sensors, mounted to each wheel as part of the valve stem, transmit tire pressure readings to the receiver module.

The Tire Pressure Monitoring System (TPMS) consists of the following components:

  • Receiver module
  • Four Tire Pressure Monitoring System sensors
  • Various Tire Pressure Monitoring System messages, which display in the instrument cluster, and a graphic displaying tire pressures
  • TPMS Warning Light

Tire Pressure Monitoring System Low Pressure Warnings

The TPMS Warning Light will illuminate in the instrument cluster, and an audible chime will be activated, when one or more of the four active road tire pressures are low. In addition, the instrument cluster will display an “Inflate to XX” message and a graphic display of the pressure value(s) with the low tire(s) in a different color.

Low tire pressure warning in 2022 Jeep Grand Cherokee.

Should a low tire condition occur on any of the four active road tire(s), you should stop as soon as possible, and inflate the low tire(s) that is in a different color on the graphic display to the vehicle’s recommended cold tire pressure displayed in the “Inflate to XX” message.

When filling warm tires, the tire pressure may need to be increased up to an additional 4 psi (28 kPa) above the recommended cold placard pressure in order to turn the TPMS Warning Light off.

The system will automatically update, the graphic display of the pressure value(s) will return to its original color and the TPMS Warning Light will extinguish once the updated tire pressure(s) have been received. The system will automatically update the graphic display of the pressure value(s) and will return to its original color. The TPMS Warning Light will extinguish once the updated tire pressure(s) have been received in the case when the ignition is ON. In the case when the ignition is OFF, the ignition on the vehicle has to be turned ON and may need to be driven for up to 20 minutes above 15 mph (24 km/h) to receive this information for the pressure value(s) to be updated.

Service TPMS Warning

The Tire Pressure Monitoring System Warning Light will flash on and off for 75 seconds, and remain on solid when a system fault is detected. The system fault will also sound a chime. The instrument cluster display will display a “SERVICE TPM SYSTEM” message for a minimum of five seconds. This message is then followed by a graphic display, with “–“ in place of the pressure value(s), indicating which Tire Pressure Monitoring System sensor(s) is not being received.

Tire pressure information not displayed for front tires in the instrument cluster display of Jeep Grand Cherokee due to a system fault.

If the ignition switch is cycled, this sequence will repeat, providing the system fault still exists. If the system fault no longer exists, the Tire Pressure Monitoring System Warning Light will no longer flash, the “SERVICE TPM SYSTEM” message will not be present, and a pressure value will be displayed instead of dashes. A system fault can occur by any of the following:

  • Jamming due to electronic devices or driving next to facilities emitting the same Radio Frequencies as the TPMS sensors.
  • 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.

No TPMS sensor in spare wheel

A TPMS sensor is not offered on any size spare tire. In either option of having a full size spare equipped or not, the tire pressure is not monitored or displayed on the cluster for the corresponding spare tire location. If you install the spare tire in place of a road tire that has a pressure below the low-pressure warning limit, upon the next ignition switch cycle, the Tire Pressure Monitoring System Warning Light will remain on, a chime will sound, and the instrument cluster display will still display a pressure value in the different color graphic display and an “Inflate to XX” message will be displayed. After driving the vehicle for up to 20 minutes above 15 mph (24 km/h), the Tire Pressure Monitoring System Warning Light will flash on and off for 75 seconds and then remain on solid. In addition, the instrument cluster display will display a “SERVICE TPM SYSTEM” message for five seconds and then display dashes (–) in place of the pressure value. For each subsequent ignition switch cycle, a chime will sound, the Tire Pressure Monitoring System Warning Light will flash on and off for 75 seconds and then remain on solid, and the instrument cluster display will display a “SERVICE TPM SYSTEM” message for five seconds and then display dashes (–) in place of the pressure value.

Once you repair or replace the original road tire, and reinstall it on the vehicle in place of the spare tire, the TPMS will update automatically.

In addition, the Tire Pressure Monitoring System Warning Light will turn off and the graphic in the instrument cluster display will display a new pressure value instead of dashes (–), as long as no tire pressure is below the low-pressure warning limit in any of the four active road tires. The vehicle may need to be driven for up to 20 minutes above 15 mph (24 km/h) in order for the TPMS to receive this information.

Tire Fill Alert

This feature notifies the user when the placard tire pressure is attained while inflating or deflating the tire. The customer may choose to disable or enable the Tire Fill Alert feature in the apps menu of the Uconnect system.

Note: The Tire Fill Alert system will only support inflating or deflating one tire at a time. The user is required to wait until the hazard lights STOP flashing or 26-30 seconds after the desired pressure is achieved in one wheel before switching to another. The Tire Fill Alert feature cannot be entered if an existing TPMS fault is set to “active” or if the system is in deactivation mode (if equipped).

The system will be activated when the system detects an increase in tire pressure while filling the tire. The ignition must be in the ON/RUN mode with the transmission in PARK for vehicles equipped with an automatic transmission. For vehicles equipped with a manual transmission, the parking brake must be applied.

Note: It is not required to have the engine running to enter Tire Fill Alert mode.

The hazard lamps will come on to confirm the vehicle is in Tire Fill Alert mode. If the hazard lamps do not come on while inflating the tire, the Tire Pressure Monitoring System sensor may be in an inoperative position, preventing the TPMS sensor signal from being received. In this case, the vehicle may need to be moved slightly forward or backward.

When Tire Fill Alert mode is entered, the tire pressure display screen will be displayed in the instrument cluster.

Tire Fill Alert Operation

  • The horn will chirp once to let the user know when to stop filling the tire, when it reaches recommended pressure.
  • The horn will chirp three times if the tire is overfilled and will continue to chirp every five seconds if the user continues to inflate the tire.
  • The horn will chirp once again when enough air is let out to reach proper inflation level.
  • The horn will also chirp three times if the tire is then underinflated and will continue to chirp every five seconds if the user continues to deflate the tire.

Selectable Tire Fill Alert (STFA) — If Equipped

The Selectable Tire Fill Alert (STFA) system is an optional feature that is included as part of the normal Tire Fill Alert system. The system is designed to allow you to select a pressure to inflate or deflate the vehicle’s front and rear axle tires to, and to provide feedback while inflating or deflating the vehicle’s tires.

Selectable Tire Fill Alert settings in the infotainment system settings of Jeep Grand Cherokee.

In the Selectable Tire Fill Alert application, which is located in the apps menu of the Uconnect system, you will be able to select a pressure setting for both the front and rear axle tire pressures by scrolling through a pressure range from ≥15 psi to XX in 1 psi increments for each axle setting. XX = the vehicle’s cold placard pressure values for the front and rear axles as shown on the vehicle placard pressure label.

You may also store pressure values chosen for each axle in the Uconnect system application as preset pressure values. Up to two sets of preset pressure values can be stored in the Uconnect system for the front and rear axle. Once you select the tire pressures for the front and rear axles that you want to inflate or deflate to, you can begin inflating or deflating one tire at a time.

Note: The STFA system will only support inflating or deflating one tire at a time. The user is required to wait until the hazard lights STOP flashing or 26-30 seconds after the desired pressure is achieved in one wheel before switching to another.

The system will be activated when the TPMS receiver module detects a change in tire pressure. The ignition must be in the ON/RUN mode, with the transmission in PARK in vehicles with an automatic transmission, and in NEUTRAL with the parking brake engaged in vehicles with a manual transmission. The hazard lamps will come on to confirm the vehicle is in Tire Fill Alert mode.

When Tire Fill Alert mode is entered, the tire pressure screen will be displayed in the instrument cluster. If the hazard lamps do not come on while inflating or deflating the tire, the Tire Pressure Monitoring System sensor may be in an inoperative position, preventing the TPMS sensor signal from being received. In this case, the vehicle may need to be moved slightly forward or backward.

Horn chirps will indicate STFA status as tires are inflated/ deflated. The horn will chirp under the following STFA states:

  1. The horn will chirp once when the selected pressure is reached to let you know when to stop inflating or deflating the tire.
  2. The horn will chirp three times if the tire is overinflated or over-deflated.
  3. The horn will chirp once again when enough air is added or removed to reach proper selected pressure level.

TPMS Deactivation — If Equipped

The Tire Pressure Monitoring System (TPMS) can be deactivated by replacing all four wheel and tire assemblies (road tires) with wheel and tire assemblies that do not have TPMS sensors, such as when installing winter wheel and tire assemblies on your vehicle. To deactivate the TPMS, first, replace all four wheel and tire assemblies (road tires) with tires not equipped with Tire Pressure Monitoring System sensors. Then, drive the vehicle for 20 minutes above 15 mph (24 km/h). The TPMS will chime, the TPMS Warning Light will flash on and off for 75 seconds and then remain on. The instrument cluster will display the “SERVICE TPM SYSTEM” message and then display dashes (–) in place of the pressure values.

Beginning with the next ignition cycle, the TPMS will no longer chime or display the “SERVICE TPM SYSTEM” message in the instrument cluster but dashes (–) will remain in place of the pressure values.

To reactivate the TPMS, replace all four wheel and tire assemblies (road tires) with tires equipped with TPMS sensors. Then, drive the vehicle for up to 20 minutes above 15 mph (24 km/h). The TPMS will chime, the TPMS Warning Light will flash on and off for 75 seconds and then turn off. The instrument cluster will display the “SERVICE TPM SYSTEM” message and then display pressure values in place of the dashes. On the next ignition cycle the “SERVICE TPM SYSTEM” message will no longer be displayed as long as no system fault exists.

Caution!

  • The TPMS has been optimized for the original equipment tires and wheels. TPMS pressures and warnings 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 or sensor damage. Customers are encouraged to use OEM wheels to ensure proper 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 dealership 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 Tire Pressure Monitoring System 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 equipped with Tire Fill Alert.
  • 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 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.

Reset the entire system

If the low tire pressure warning light won’t turn off due to a glitch in the tire pressure monitoring system, it may be possible to reset the TPMS system by resetting all on-board computers in your Grand Cherokee. This method should only be considered as a last resort, when all else fails.

Disconnect both negative and positive terminals of the battery.

You can reboot all the on-board computers by disconnecting the main 12 volt battery for a few minutes. Remove the cable from the negative terminal of the battery first, then from the positive terminal. With the battery disconnected, press the horn button a few times and turn on the headlights to drain out all the residual electricity from the system. After about 15 minutes, reconnect the battery in reverse order: positive cable first, then negative cable.

Tire pressure keeps getting low

If the TPMS warning light turns on frequently in your Grand Cherokee, and the tire pressure is also decreasing after you have reinflated the tires, there may be an air leak. One or more of the tires may have been punctured by an external object, or the air may be leaking from a defective value stem.

A punctured tire can be plugged with a tire repair kit if the puncture is not near the sidewall.

Use OBD2 scanner for diagnosis

Since Jeep Grand Cherokee is 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 Bluetooth based diagnostic device which you can connect to the OBDII port in your vehicle and use your mobile phone for diagnosis. You will need to download the “BlueDriver OBD2 Scan Tool” app from the App Store on your iPhone, or from Google Play Store if you have an Android phone.

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.

Author: Nabeel K
Email: nabeel@wheelsjoint.com