Has anyone really had their TPMS adjusted?
I also have a friend that works at a tire store and they have a book for doing this procedure on all makes and models. He says its very common for people to switch sizes and brands when their factory tires are being replaced and obviously pressure recommendations vary from tire to tire.
• The self-dimming rear-view mirror standard on Lariat now includes an integrated compass"
- I have an 08 F-250 Lariat with a build date of Sep 07 but my compass is in the dash, right by the gear selection indication?
Denali and half of the time in the cars I rent from Avis. This is definitely not something I care to ever have on my truck where I go back and forth between 45 and 80 lbs depending on my load.
Ford Trucks for Ford Truck Enthusiasts
Principles of Operation
NOTE: The smart junciton box (SJB) is also referred to as the generic electronic module (GEM).
The tire pressure monitoring system (TPMS) monitors the air pressure of all 4 road tires. The wheel-mounted tire pressure sensors transmit via radio frequency signals, to the SJB. TPMS functionality is integral to the SJB. These transmissions are sent approximately every 60 seconds when the vehicle speed exceeds 32 km/h (20 mph). The TPMS function compares each tire pressure sensor transmission against a low-pressure limit. If it has been determined that the tire pressure has fallen below this limit, the SJB communicates this on the vehicle communication bus to the instrument cluster. The instrument cluster then illuminates the TPMS indicator and displays the appropriate message(s) in the message center (if equipped).
For vehicles with different front and rear tire pressures (such as the E-Series and certain F-Series), the tire pressures must be adjusted and the tire pressure sensors must be trained following a tire rotation. Failure to train the sensors will cause the TPMS indicator to illuminate.
For vehicles with the same tire pressures for front and rear tires, tire rotation will not affect the system.
If you are having trouble i would have the dealer adjust it, the process is quiet lenghty. The dealer has detailed information how to adjust. If they can't i would seek out another dealer.
The keyword here is "trained" nothing about this training allows you to adjust the "low pressure limit". All the training does is tell the vehicles computer where each tire sensor is located. These sensors are then re-associated with a number and a "low pressure limit" pre-programmed in the trucks computer.
In other words, if your driving a vehicle that has a 80/65psi rating its expected that you have the following. Tire number 1 (LF) is expected to have 65psi, tire number 2 (RF) is expected to have 65psi, tire number 3 (RR) is expected to have 80psi and tire number 4 (LR) is expected to have 80psi. If you move tire number 4 (LR) to tire position 1 (LF) and re-air it to 65psi, the warning light will go off because that sensor has been associated with tire position 4 which expects 80psi. For this reason, you have to perform the TPMS Reset Procedure.
As for how to perform the TPMS Reset Procedure, here it is from the 2008 manual,
Note: It is recommended that you read the entire procedure before attempting.
Note: To enter the reset mode, Steps 1–5 MUST be completed within 60 seconds.
- The key must be in the ignition and the ignition turned to OFF/LOCK. Press and release the brake pedal.
- Cycle the ignition from OFF/LOCK to RUN three (3) times ending in the RUN position. DO NOT start the engine.
- Press and hold the brake pedal for two (2) seconds, then release.
- Turn the ignition to OFF/LOCK (DO NOT remove the key.)
- Cycle the ignition from OFF/LOCK to RUN three (3) times ending in RUN. DO NOT start the engine.
If reset mode has been entered successfully, the horn will sound once, the TPMS indicator will flash and the message center will display TRAIN LF TIRE.
If after repeated attempts to enter reset mode, the horn does not sound, the TPMS indicator does not flash and the message center does not display TRAIN LF TIRE, seek service from your authorized dealer.
TPMS reset sequence
The TPMS system needs to be reset starting with the left front tire in the following clockwise order:
1. Left front tire
2. Right front tire
3. Right rear tire
4. Left rear tire
- Left front tire: Place the TPMS reset tool against the left front tire where the tire meets the rim, opposite from the valve stem.
This is where the sensor is located inside the rim.
The tool needs to be held against the tire sidewall opposite the valve stem as illustrated with the arrow on the tool pointing towards the rim; do not use the tool with the arrow pointing away from the rim as it may not activate the sensor. - Press and release the green button and hold the tool to the tire sidewall until the horn sounds. The red light on the TPMS reset tool will illuminate while the tool is active. The horn will sound once within 10 seconds to indicate the process was successful.
Note: If a double horn chirp is heard, repeat the procedure. If a single horn chirp is not heard, move the vehicle to rotate the wheels at least a 1⁄4-turn and repeat the procedure. If the horn does not sound while attempting to reset any wheel, seek service from your authorized dealer. - Perform Steps 1 and 2 on the right front, right rear and finally the left rear tires.
Successful completion of the reset procedure can be verified by turning the ignition to OFF without the horn sounding. If two short beeps are heard, the reset procedure was unsuccessful and must be repeated.
If after repeating the procedure two short beeps are heard when the key is turned to OFF, seek assistance from your authorized dealer.
As in this example, the rear tires rotated to the front and properly inflated to 50 psi (345 kPa) for the front axle would falsely illuminate the low tire warning indicator as they are still trained for the rear positions which require 80 psi (552 kPa).
In other words, if your driving a vehicle that has a 80/65psi rating its expected that you have the following. Tire number 1 (LF) is expected to have 65psi, tire number 2 (RF) is expected to have 65psi, tire number 3 (RR) is expected to have 80psi and tire number 4 (LR) is expected to have 80psi. If you move tire number 4 (LR) to tire position 1 (LF) and re-air it to 65psi, the warning light will go off because that sensor has been associated with tire position 4 which expects 80psi. For this reason, you have to perform the TPMS Reset Procedure.
As for how to perform the TPMS Reset Procedure, here it is from the 2008 manual,
Then there's some nice examples with illustrations followed by the following message,
jr
All I'm doing is describing how the system works. 
Mine are 65/65 all around and my TPMS tool hasn't left the glove box either.


