March 16, 2010
Amazing Expedition
Pressure sensors are wheel-mounted
By: Mike Manges
Figure 1
SUBJECT VEHICLE: 2009 Ford Expedition.
SENSOR IN TIRE? No (mounted on wheel).
RESET PROCEDURE? Yes (whenever a new sensor has been installed).
SPECIAL TOOLS NEEDED? Yes (TPM Activation Tool 204-363).
The 2009 Ford Expedition’s tire pressure monitoring system (TPMS) uses wheel-mounted tire pressure sensors that send information to the vehicle’s Smart Junction Box (SJB) once every 60 seconds when the vehicle is moving at speeds in excess of 20 mph.
If pressure levels drop too low, the SJB sends a message to the instrument cluster. The low pressure light then comes on.
Sensors are battery-operated and are mounted to metal brackets (also called cradles) on the wheels inside the tires. The sensors are mounted 180 degrees from the valve stem.
Sensor swap
Before you can service the Expedition’s TPMS, you must first demount the tire from the wheel using the tire changer manufacturer’s guidelines. Keep in mind that the tire and wheel must always be correctly matched.
Use only wheels and wheel nuts that have been designed for current model year Ford trucks. Tire pressure sensors are not engineered to be used with aftermarket wheels, which may not fit or function properly.
Ford advises using Digital Tire Gauge (204-354) any time tire pressure levels are measured to ensure that accurate measurements have been taken.
When installing a new sensor, make sure the color of the sensor being installed matches the color of the sensor that has been removed. Do not mix-and-match different colored sensors.
Also bear in mind that the sensor is mounted to the rim 180 degrees opposite the valve stem and is held in place by a stainless steel strap. Valve-mounted and strap-mounted sensors are not compatible. Follow these steps to demount the tire:
1. Remove the tire and wheel assembly.
2. Position the assembly on the tire machine with the valve stem at the 6 o’clock or 12 o’clock position. Separate both beads. Index mark the valve stem and weight positions.
3. Demount the tire from the rim.
4. Using a pocket screwdriver, remove the sensor locking clip.
Detach the sensor from the cradle and remove the sensor. Do not use excessive force.
Now you’re ready to install the new sensor. Follow these steps:
1. Position the sensor into the cradle by inserting the hinge end of the sensor into the hook end of the cradle (see Figure 1). Push the opposite end of the sensor down into the cradle. Ensure the sensor has been fully seated.
2. Insert a new locking clip into the sensor.
3. Place the wheel on the turntable of the tire machine so that the sensor is at the 6 o’clock position and the valve stem and machine arm are at the 12 o’clock position.
4. Lube and mount the tire onto the wheel starting at 90 degrees from the sensor.
5. Inflate the tire to the specified pressure and install the tire and wheel assembly.
Now it’s time to train the new tire pressure sensors you have installed.
Sign up for our Enews and receive the latest news, trends, and product information right in your e-mail inbox.