Another TPMS sensor fault

[waxclan]

2007 XLT 93K miles. Tire pressures 44-45 psi, no alarms at start. Right at 20 minutes into the drive I get a sensor malfunction alarm. It has reset on its own and then realarmed. I had a tire shop check the sensors and all read correctly. There is Fordtechmakuloco video () that discussed the exact problem I am experiencing including the timing of the alarm but do not have any chargers in the car. Has anyone else had this experience?

 

[waxclan]

2007 XLT 93K miles. Tire pressures 44-45 psi, no alarms at start. Right at 20 minutes into the drive I get a sensor malfunction alarm. It has reset on its own and then realarmed. I had a tire shop check the sensors and all read correctly. There is Fordtechmakuloco video () that discussed the exact problem I am experiencing including the timing of the alarm but do not have any chargers in the car. Has anyone else had this experience?

Hearing nothing - I plan on installing some aftermarket sensors to see if the batteries on the oem sensors have weakened enough to not send a strong enough signal. After that, I'll try and fashion an antenna system to let the rear sensors talk to the module.

 

[BrightExplorer]

My wife's Highlander was throwing a tire pressure light...
It was her spare tire hanging.
Don't overlook that.

 

[DavidEBSmith]

We would get sensor fault warnings about 50 minutes into a trip, we got rid of an aftermarket Bluetooth adapter and the TPMS fault never came back.

 

[waxclan]

We would get sensor fault warnings about 50 minutes into a trip, we got rid of an aftermarket Bluetooth adapter and the TPMS fault never came back.

No adapters in the car, tried remote antenna on the right rear and no change, so now I'm driving with the obd2 plugged in to see if I can get a code. Otherwise, it is to the dealer to have them replace and flash the monitor unit under the dash (smart junction box).

 

[MotorCityFats13]

My wife's Highlander was throwing a tire pressure light...
It was her spare tire hanging.
Don't overlook that.

good thing ford didnt care about putting a sensor in the spare

 

[MotorCityFats13]

No adapters in the car, tried remote antenna on the right rear and no change, so now I'm driving with the obd2 plugged in to see if I can get a code. Otherwise, it is to the dealer to have them replace and flash the monitor unit under the dash (smart junction box).

before dishing out tons of cash to a dealer you can score 4 sensors on ebay for $85 and the relearn dongle for around $12... i been dealing with the light in my cluster for about 4 years and finally just bought the stuff i needed and 2 hours of my time in the garage so unless you actually know you need a new module this can be done yourself

 

[waxclan]

before dishing out tons of cash to a dealer you can score 4 sensors on ebay for $85 and the relearn dongle for around $12... i been dealing with the light in my cluster for about 4 years and finally just bought the stuff i needed and 2 hours of my time in the garage so unless you actually know you need a new module this can be done yourself

already installed new sensors in the tires and the system acts the same as with the old sensors.

 

[waxclan]

In doing some additional research I find that, besides the smart junction box (fuse box and security system) there is a tire pressure monitor receiver, ford part 7L2Z15604CA . Does anyone know where this is located (2007 XLT)?

 

[MakinJeepsWeep!]

Did you check the spare? I don't know about your exact model but on at least 4 vehicles I've fixed these on 2 being Fords (F250 & Mounty) it was the spare was low. Also 45 psi seems a bit high for tires pressure. I could be wrong just seems high. Hope this helps or you get it fixed best of luck!

 

[MotorCityFats13]

Did you check the spare? I don't know about your exact model but on at least 4 vehicles I've fixed these on 2 being Fords (F250 & Mounty) it was the spare was low. Also 45 psi seems a bit high for tires pressure. I could be wrong just seems high. Hope this helps or you get it fixed best of luck!

these dont have 5 sensor systems and my tires max at 51 and i used to do 45 until last week when i noticed my last tire i changed was wearing in the center

 

[MakinJeepsWeep!]

Cool deal buddy, i learn stuff everyday now i know ahead of time it isnt the spare haha. If it helps i personally take the max tire psi and psi on door sticker and find the mid point so tire max is 50 door says 28 your psi would be 39 psi max or hot so i would make it roughly 36 psi. On my 06 merc mounty i make sure the psi does not go over 40 hot. Usually about 36-38 is where i put it depending on summer/winter. Its on street tires. I can go into more detail and make this make more sense in a private message if you would like with using three sets i run on my trucks.

 

[loooney2ns]

In doing some additional research I find that, besides the smart junction box (fuse box and security system) there is a tire pressure monitor receiver, ford part 7L2Z15604CA . Does anyone know where this is located (2007 XLT)?

Left side kick panel.

 

[waxclan]

Yea, found out it is the whole fuse box assembly. Tried running a 315 mHz sized antenna at each rear wheel and ran single strand to a similar coil at the left kick panel. No joy with that. Strangest thing, alarm comes in at the 20 minute mark. I come to a stop and put it in park for abouty 30 seconds then take back off and the alarm clears. Reading up on TPMS repeaters (signal boosters) - used to allow the signals from a trailer to be transmitted to the receiver in the cab. One company described the symptoms similar to my experience, that RF interference can mess with the pressure sensor signal. I'm now wondering if old wires (mine is a 2007 with 93K on it and original plugs and wires) can cause interference so they are the next step as I should do that anyway.

 

[Blackexplorer06]

I got tired of fooling with the sensors. Had my mechanic turn it OFF with Forscan.

 

[waxclan]

I may need to try that next. No luck on plugs and wires (although still good to do). Bought a 433 mHz tpms repeater and installed a 315 mHz antenna and am trying some repeater positioning but not having much luck with that yet either. Now I need to find a shop that has that style OBD2 sensor that can stop functions.