High Pitch tone

[shutmdown]

Anyone notice a high pitch tone when the car is just sitting with the key in the ACC position?

 

[VCFP153]

No

 

[peterk9]

Anyone notice a high pitch tone when the car is just sitting with the key in the ACC position?

Does the vehicle have a 120V power outlet?

Peter

 

[shutmdown]

I haven't seen one. It appears the sound is present when the car is off and in both the ACC and ON position.

 

[peterk9]

Several members reported a high pitch sound before and it was caused by the power inverter. High pitched interior noise. Constant

Peter

 

[VCFP153]

Do you have any kind of aftermarket comm equipment mounted?

 

[shutmdown]

Nope

 

[Gincophie]

Anyone notice a high pitch tone when the car is just sitting with the key in the ACC position?

Have you been able to solve?

I am experiencing high pitched tone on my 2001 Sport Trac with engine running (no warning lights). When driving, tone goes off when I accelerate, resumes when I brake or when standing still.

 

[VCFP153]

Have you been able to solve?

I am experiencing high pitched tone on my 2001 Sport Trac with engine running (no warning lights). When driving, tone goes off when I accelerate, resumes when I brake or when standing still.

If that's all that's wrong with your nearly 20-year-old Sport Trac, you're doing OK.

 

[peterk9]

Have you been able to solve?

I am experiencing high pitched tone on my 2001 Sport Trac with engine running (no warning lights). When driving, tone goes off when I accelerate, resumes when I brake or when standing still.

Have you posted this in the Sport Trac forum? You may have better luck there if other owners have had the same issue? 2001-2005 Explorer Sport Trac

Peter

 

[Bobs2018ExplorerSport]

On my 2018, if I push the Start button (keyless ignition), but don't step on the gas pedal (to actually start it), it's in Accessory mode, and until I either tap the button once more (which allows me to run the radio without anything else "on"), there IS a very high-pitched sound coming out from the engine compartment. None of it seems to hurt anything.

Not surprisingly, the same sound is present whenever I've gone into the BCM programming using FORScan... since you have to leave it in the accessory mode while doing any programming.

Perhaps it has something to do with certain electronics being activated during that mode? (It reminds me of my old vintage Motorola mobile radio units... whenever you keyed the transmitter, you could easily hear the final transistors "sing", as they created the outgoing RF signal)...

 

[bill32399]

It's most likely the fuel pump running.

 

[peterk9]

The fuel pump is part of the fuel tank which is located under the driver's side seat. It isn't in the engine. Keep in mind that the initial; post concerned a PIU. In the retail models the issue was the power inverter as mentioned above. Not saying that Bobs2018Explorer is the same issue but it was easy enough to check by removing the fuse for the inverter.

Peter

 

[bill32399]

The fuel pump is part of the fuel tank which is located under the driver's side seat. It isn't in the engine. Keep in mind that the initial; post concerned a PIU. In the retail models the issue was the power inverter as mentioned above. Not saying that Bobs2018Explorer is the same issue but it was easy enough to check by removing the fuse for the inverter.

Peter

The OP did not say where the noise was coming from. The fuel pump is not under the drivers seat either and I am not sure where you got that it was in the Engine. The 110v inverter is on the passenger side at the base of the A pillar. My 2015 PIU has an inverter so I don't know why we need to keep that in mind. You will find the fuel pump just behind the rear seat and it is in the fuel tank. It emits a high pitch noise when the truck is turned on. It also can do this for a short period when the key is inserted. It was never said this was the issue just a possible cause.

Maybe the OP could describe better the location of where he is hearing the noise so we can better help diagnose his problem.

 

[BrettS.]

If it was me I would remove/reinstall one fuse/relay at a time to find out what circuit is causing the noise. Then troubleshoot that circuit. Fuel pump and inverter are most likely but anything could be wrong.

 

[peterk9]

The OP did not say where the noise was coming from. The fuel pump is not under the drivers seat either and I am not sure where you got that it was in the Engine. The 110v inverter is on the passenger side at the base of the A pillar. My 2015 PIU has an inverter so I don't know why we need to keep that in mind. You will find the fuel pump just behind the rear seat and it is in the fuel tank. It emits a high pitch noise when the truck is turned on. It also can do this for a short period when the key is inserted. It was never said this was the issue just a possible cause.

Maybe the OP could describe better the location of where he is hearing the noise so we can better help diagnose his problem.

Sorry Bill, I got mixed up with the 2020 Explorer regarding the fuel tank. Too much jumping back and forth between the two forums. As for the high pitched noise, it was a problem on several Explorers and the cause was the 120V power inverter. High pitched interior noise. Constant
In post #11 the member said it was coming from the engine compartment. Noises can be tricky to pin down at times so a noise from that position in the dash might sound like it is coming from the engine bay. Also, I did not say the fuel pump was in the engine. I said it was not in the engine. I know it is on top of the fuel tank on the 5th gen and is located in the rear of the vehicle as I've pointed that out many times in previous posts.

Peter

 

[Bobs2018ExplorerSport]

Ya know, at least in my 2018, perhaps that IS the fuel pump charging-up that I'm hearing?

It kinda makes sense. I also know that there is a big removeable cover or plug in the area under the passenger seat... perhaps that is for easier R&R of a failed fuel pump, from above for a change (instead of having to drain and drop the tank)? Having that would indeed be very smart!

 

[Gincophie]

Thanks for your replies! I did not post (yet) in Sport Trac forum but probably will.

Already tried pulling every fuse: tone continues regardless. It sure sounds like an electronic tone. Can't tell from where. Could be dash could be under/behind seat, neither would surprise me.

NEW INFO: high pitched tone immediately stops when I turn on the A/C or heat. Doesn't matter what blower speed. Doesn't matter which vent position. Turn the climate control to Off = high-pitched tone returns. There is no "Off" position on the fan speed control knob, so the climate control is the only on/off switch for the blower. I'm now suspecting the blower circuit. Maybe an unhappy relay or some other component? Guess I need to open up the dash and try to see where the tone is coming from.

 

[shutmdown]

On my 2018, if I push the Start button (keyless ignition), but don't step on the gas pedal (to actually start it), it's in Accessory mode, and until I either tap the button once more (which allows me to run the radio without anything else "on"), there IS a very high-pitched sound coming out from the engine compartment. None of it seems to hurt anything.

Not surprisingly, the same sound is present whenever I've gone into the BCM programming using FORScan... since you have to leave it in the accessory mode while doing any programming.

Perhaps it has something to do with certain electronics being activated during that mode? (It reminds me of my old vintage Motorola mobile radio units... whenever you keyed the transmitter, you could easily hear the final transistors "sing", as they created the outgoing RF signal)...

Bob, thanks for chiming in, I haven't been able to pinpoint the location of the noise, but it definitely seems to be coming from the front of the car. However, it does seem to have that same high pitched sign when I am in ForScan making changes inside the car. So something definitely related to certain electronics.

Took it to the Ford Dealer and they couldn't figure it out. They ended up blaming it on the CenCom hardware installed....