"Tire Pressure Sensor Fault" - how to isolate which sensor?

[Delta Jim]

My DIC says "Tire Pressure Sensor Fault" and the TPMS light is on. During a several hour highway drive, this DIC message will appear and disappear (as well as the TPMS light). I reset/clear the DIC when the message shows but the TPMS light will also go out after a period of driving.

I have reset the tire sensors twice per Ford's recommended process and all respond/reset normally. There are no DTCs in the ECU. How does one go about determining what tire pressure sensor is flaky or causing the fault? Does the spare also have a sensor? Ford procedure does not have you reset the spare, so I assumed it does not.

Truck runs stock 20" wheel/tire combo and has been rotated several times without issue. I mostly try to avoid the dealer service folks if possible so trying the brain trust on the forum first. Any experience on this issue is appreciated.

[WildStyle]

Spare does not run a sensor in it.

All tires are aired up to factory door post spec? If not it will set a light.

You have a TPMS reset tool?

[Svenster]

I have the same issue as Delta Jim. Have taken to the dealer numerous times and they can't figure it out without having the bad sensor message on the display. Dealer reset the TPMS several times, but was told to bring it back when the bad sensor is displaying so dealer can hook it up to computer. Every time I get the bad sensor message and head to the dealer, its turn off before I get there. Very fustrating. Mine comes on 1-3 times per week, and will stay on for 10-15 minutes before going away. Everything is stock.

[Delta Jim]

Glad to hear I'm not the only one, Svenster. Hoping a Ford Mechanic from the forum will chime in...

IMO, the whole TPMS system is lame. A reliable tire gauge is in every vehicle I own. Thank the idoits in their Explorers that never checked nor aired their tires, rolled, and blamed Ford.

To WildStyle, the issue is not TMPS light per se (eg, low tire pressure) but rather a 'Tire Pressure Sensor Fault'. The tire sensor(s) are dropping signal or 'faulting' in some manner. Yes, tires are aired to spec and I've reset the TMPS sensor by sensor twice per Ford's procedure. Doesn't seem to matter, the 'Fault' message in the DIC reappears. It is intermittent so I suspect their is a bad sensor in the lot. There must be a way to test/determine which sensor is flaky.

[Delta Jim]

for any knowledge on how to solve this issue....

[GamblerHydra]

I am not sure if this is true, but had the same issue and was told by a guy at discount tire checking my tires that if your tire pressure gets to high that can cause it to.

[JUGERNAUT]

Originally Posted by Svenster

I have the same issue as Delta Jim. Have taken to the dealer numerous times and they can't figure it out without having the bad sensor message on the display. Dealer reset the TPMS several times, but was told to bring it back when the bad sensor is displaying so dealer can hook it up to computer. Every time I get the bad sensor message and head to the dealer, its turn off before I get there. Very fustrating. Mine comes on 1-3 times per week, and will stay on for 10-15 minutes before going away. Everything is stock.

ok that is bunk and this is why, any time any code is set period there will be binary to follow. what i mean is when any light is set it will set a code.and it will store a code.so there will be a sensor fault in the pid monitor area of the ids. if the tech was informed with good training he would now this. tell them next time you take it to look at pid monitor data and all the faults will be in there. trust me.

just to back up what i say here it is right from the manual
TPMS Last Warning Event PID Definitions

The TPMS uses the TPMS last warning event PIDs to store detailed information about the last 5 times the TPMS warning indicator was activated. These PIDs can be used to acquire more information about a particular TPMS event.

EVT1_IGN through EVT5_IGN
The number of key cycles since the TPMS warning indicator was activated. This PID cycles from zero to 255 and then starts over from zero again. This can be used to determine how long ago a TPMS event occurred and the time (in key cycles) between events.

EVT1_TLOC through EVT5_TLOC
This is the last programmed location for the sensor identifier causing each TPMS event. Due to tire rotation, the sensor may no longer be at the original location. It is suggested that all the PIDs be recorded, the system retrained, and then the sensor identifier PIDs be used to pinpoint the actual location of each sensor.

EVT1_PSI through EVT5_PSI
This is the tire pressure associated with each TPMS warning indicator event. This can be used along with the function code to clearly identify the TPMS events that were strictly due to low pressure. It can also be used to determine when a sensor is transmitting inaccurate tire pressure.

EVT1_STAT through EVT5_STAT
Describes the warning status of each TPMS event by using the information received from the TPMS status (TP_STAT) PID. If there is a communication issue, the status could be Normal.

so go back and make them fix it correctly im glad i dont work there i would be pissed off.

also if they rotated your tires i hope they reset the monitors cause that will set light too if they didnt adjust presures. i hope this helps.

[JUGERNAUT]

Originally Posted by Delta Jim

Glad to hear I'm not the only one, Svenster. Hoping a Ford Mechanic from the forum will chime in...

IMO, the whole TPMS system is lame. A reliable tire gauge is in every vehicle I own. Thank the idoits in their Explorers that never checked nor aired their tires, rolled, and blamed Ford.

To WildStyle, the issue is not TMPS light per se (eg, low tire pressure) but rather a 'Tire Pressure Sensor Fault'. The tire sensor(s) are dropping signal or 'faulting' in some manner. Yes, tires are aired to spec and I've reset the TMPS sensor by sensor twice per Ford's procedure. Doesn't seem to matter, the 'Fault' message in the DIC reappears. It is intermittent so I suspect their is a bad sensor in the lot. There must be a way to test/determine which sensor is flaky.

actually it is the goverment who mandated this so thank them.

[Delta Jim]

Thanks for this info, Jugernaut. I will have my dealer pursue accordingly if and when I let them work on my truck.

Originally Posted by JUGERNAUT

ok that is bunk and this is why, any time any code is set period there will be binary to follow. what i mean is when any light is set it will set a code.and it will store a code.so there will be a sensor fault in the pid monitor area of the ids. if the tech was informed with good training he would now this. tell them next time you take it to look at pid monitor data and all the faults will be in there. trust me.

just to back up what i say here it is right from the manual
TPMS Last Warning Event PID Definitions

The TPMS uses the TPMS last warning event PIDs to store detailed information about the last 5 times the TPMS warning indicator was activated. These PIDs can be used to acquire more information about a particular TPMS event.

EVT1_IGN through EVT5_IGN
The number of key cycles since the TPMS warning indicator was activated. This PID cycles from zero to 255 and then starts over from zero again. This can be used to determine how long ago a TPMS event occurred and the time (in key cycles) between events.

EVT1_TLOC through EVT5_TLOC
This is the last programmed location for the sensor identifier causing each TPMS event. Due to tire rotation, the sensor may no longer be at the original location. It is suggested that all the PIDs be recorded, the system retrained, and then the sensor identifier PIDs be used to pinpoint the actual location of each sensor.

EVT1_PSI through EVT5_PSI
This is the tire pressure associated with each TPMS warning indicator event. This can be used along with the function code to clearly identify the TPMS events that were strictly due to low pressure. It can also be used to determine when a sensor is transmitting inaccurate tire pressure.

EVT1_STAT through EVT5_STAT
Describes the warning status of each TPMS event by using the information received from the TPMS status (TP_STAT) PID. If there is a communication issue, the status could be Normal.

so go back and make them fix it correctly im glad i dont work there i would be pissed off.

also if they rotated your tires i hope they reset the monitors cause that will set light too if they didnt adjust presures. i hope this helps.

[Delta Jim]

Originally Posted by JUGERNAUT

actually it is the goverment who mandated this so thank them.

yep, the govt postion on most things... 'you are too stupid to think for yourself, so we are going to create legislation that does it for you'...