Grand Cherokee 2WD V6-3.7L (2008)
Tire Pressure Sensor: Description and Operation
NOTE: On vehicles equipped with a Tire Pressure Monitoring System (TPMS), when the spare tire pressure sensor is replaced with a new
pressure sensor, a diagnostic scan tool MUST be used to run a routine that will program the new pressure sensor ID into the Wireless Ignition
Node (WIN). Please copy the ID number off of the new pressure sensor before installing it into the spare tire. Then follow the programming
steps outlined in the diagnostic scan tool for: "Program Spare Tire Sensor ID" under Miscellaneous Functions for the "WIN/Wireless Control
Module" menu item as appropriate.Then install the spare tire with one of the active road tires.
NOTE: If replacing the WIN, the spare tire must be dismounted from its wheel to access and note the spare tire pressure sensor ID. Then follow
the programming steps outlined in the diagnostic scan tool for "Program Spare Tire Sensor ID" under Miscellaneous Functions for the
WIN/Wireless ignition Node menu item as appropriate. The WIN learns the Placard Pressures from the Front Control Module (FCM)
configuration on the bus. Go to "Read Placard Pressure" under "Data Display" for the "WIN/Wireless Ignition Node" and confirm the
placard pressure reported matches Tire Inflation Pressure (Placard) Label.
On vehicles equipped with Tire Pressure Monitoring System, one tire pressure sensor (6) is mounted to each wheel in place of the traditional tire valve
stem. Each sensor has an internal battery that lasts up to 10 years. The battery is not serviceable. At the time of battery failure, the sensor must be
The TPM system operates on a 433 MHz radio frequency. The 433 MHz sensors can be easily identified by a gray sensor body (with an oval insignia)
and a black valve cap (2).
CAUTION: Although 315 MHz and 433 MHz sensors are identical in size and shape, they are not interchangeable. Always make sure the
correct sensor is being used.
NOTE: Sensors may be identified by valve stem cap color. From the factory, 315 MHz sensors have a gray valve stem cap while 433 MHz
sensors have a black valve stem cap. Otherwise, once mounted inside a tire and wheel assembly you are not able to visually tell the difference
between a 315 MHz and 433 MHz sensor. The tire must be dismounted allowing visual inspection of the sensor body.
NOTE: If aftermarket wheels are installed and do not contain tire pressure sensors, the system will not function properly and the driver will be
continuously notified of a system malfunction.
The TPM sensors are designed for original style factory wheels. It is not recommended to install a tire pressure sensor in an aftermarket wheel.
(This could cause sealing and system performance issues).