High pitched tone

LS4me

LS4me

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The first time after start-up I hit between 2700 and 3000 rpm I get this very high pitched tone from the speakers. It seems there is a bulletin out on this. I don't remember the number off-hand but it says (paraphrase) that some THX/AdvanceTrak equipped cars will exhibit a tone the first time passing 2500rpm after start-up. This is considered normal and no action is to be taken. Seems it is an issue between the AT and THX. They have to replace the head unit for another issue, so I hope this cures the problem. In a car that costs this much this is totally unacceptable! I know it's an orphan car and all, but if Ford ever wants my business again, they will not let crap like this happen! Sounds to me like the engineers didn't want to take the time to figure out the problem and management just decided to call it "normal"! What a load of crap! Grrrrrr.......

So I unplugged the amp this morning. On my way to work I ran through the offending rpm and voilá, no tone. I pulled over, plugged the amp back in and ran through the offending rpm again. Still quiet with no tone.

I assume my next move would to put a noise filter on all 3 power lines. That or drive in silence.......

Ideas?????
 
i have had my head unit replaced for a minor malfunction in the screen. it did nothing with the high pitched sound. THe way i see it, that sound is just letting me know that the abs is running a diagnostic. Every car i have owned has quirks. i Just tried to find a positive in it. Unlike my jaguar XJ's, which cost much more, the radio at least works. If you think this issue is bad, i recomend never buying a Jaguar.
 
No ideas on how to silence this tone? Ground loop isolator? Noise filter? There must be some electronic whiz out there.....
 
Yep, my 06 does this too. The navigation head was replaced (due to jams in the CD changer), but it did not resolve this problem. We're stuck with it. The noise seems to be generated in the nav head, so you can't filter it out without filtering out that frequency range of the music.
 
joegr said:
Yep, my 06 does this too. The navigation head was replaced (due to jams in the CD changer), but it did not resolve this problem. We're stuck with it. The noise seems to be generated in the nav head, so you can't filter it out without filtering out that frequency range of the music.
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Except that Lincoln says it's a conflict between the THX and a self-check the Advancetrac is running. That's why I thought a simple noise filter on the power leads to the amp would cure the tone. For me the pitch is quite painful. I spend too much time trying to stay below 2500 rpm.
 
Hmm... actually, I replaced the THX/nav HU with a Pioneer Z110BT. Will check whether I'm still having this shennanigans next time out.
 
Here is the "memo":

19419 2003-2006 Lincoln LS- High frequency noise in passanger compartment-Advancetrac system- Do not attempt repairs/replacement- Normal operation Some 2003-2006 Lincoln LS vehicles equipped with Advancetrac and a THX audio/Navigation system may exhibit a high frequency noise in the passanger compartment for 2 to 3 seconds during the functional self-check of the Advancetrac system. This self-check happens once per key cycle the first time the engine reaches 2500 rpm or higher, with the vehicle speed between 15 and 55 mph, while not braking. This is a normal characteristic of the vehicle, so no repair should be attempted.

Effective date: 10/06/2006
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I think my 04 does this when I turn the key to run without starting the car yet on a cold start.

Unless it is a different noise.

It is a 1-2 second high pitched noise coming from the passenger floor area that sounds almost like a DJ scratching a disc in a song lol. That is how I would describe it. But again this is before starting the car.. so I dunno
 
I read this and thought it didn't happen to me but I heard the ringing today and It just hit me that I've been hearing that ringing for a while now, just got use to it and forgot about it. Mine isn't that loud, just a little 2 second ring.
 
Alax7 said:
I read this and thought it didn't happen to me but I heard the ringing today and It just hit me that I've been hearing that ringing for a while now, just got use to it and forgot about it. Mine isn't that loud, just a little 2 second ring.
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I would love to forget about it/tune it out!! Unfortunately, despite my occupation I still have excellent hearing. Combine that with a pitch that feels like it's piercing my brain and a slight case of OCD (actually, I'm a perfectionist) and it's driving me crazy.
 
Andrizzle said:
I think my 04 does this when I turn the key to run without starting the car yet on a cold start.

Unless it is a different noise.

It is a 1-2 second high pitched noise coming from the passenger floor area that sounds almost like a DJ scratching a disc in a song lol. That is how I would describe it. But again this is before starting the car.. so I dunno
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That doesn't sound like the same thing. It is a high frequency tone that comes from all of the door speakers for three to five seconds.
 
duckytoos said:
I'd say just buy a couple 12's and cancel the noise out with some BASS!!! haha
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Were it that easy. The tone is a quite high pitch.


Wellllllll.......

I installed a ground-loop isolator on each of the 4 power lines to the amp. Actually, 3 are power inputs and one is the amp engage line. Result; NOTHING. The tone is still there angry. :mad: There are 4 wires leaving the amp that drive the subs that I didn't touch.

I sure hope this can be resolved as the pitch of the tone is painful.
 
THX Noise

LS4me said:
Mr. Howie..............
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I have a 2003 in the garage now and it does not make the noise.

We did not sell as many 2006 LS at the dealership, so there are less of them to sample from.

Ford likes to combine too many circuits on one power source. For example the electric water circulation pump, the A/C clutch, and the water flow control solenoid pack are on one 10 amp fuse. So if the fuse blows which one is it. I have to add separate fuses in the fuse box that look like factory fuses using empty locations to diagnose the problem. They probably have the amp and the advance track components to close in the power distribution.

I did have some noise issues in after-market touch screens with blue tooth when the hands free phone was operated through the radio. I had to reroute the (+) (Battery power all the time) at the connector behind the radio. I disconnected the radio from the factory (12V+ at all times) and ran a 10 gauge wire directly to the battery junction box in the trunk. This was connected to the after-market Yellow wire on the touch screen. The wire routes nicely through the console under the carpet on the hump, under the insulation pad under the rear seat, though the passenger side seat hinge into the factory conduit to the battery junction box. I installed an ATO fuse & fuse holder plugged directly into one of the unused battery male spade connectors inside the box. Noise gone.

On your THX system check the electrical diagram alldatadiy.com pay for a subscription. Go to diagrams/electrical/radio and see which circuit provides battery power the radio amp. I would start by doing this and see if the noise goes away. May have to reroute power from the Nav unit if this does not work. This is obviously a problem that Ford does not want to mess with.

On some New Ford SUV's I could pick up the network communications digital pulses on an AM radio. Customer could also do so on the car radio. Ford engineers came to the dealer right away to see me and realized this was a real problem for AM talk radio lovers in St. Louis. They said they were working on the cars 5 years ahead and did not want to come up with a fix for it, but would consider it in future designs. Typical response from a car manufacturer. I told them that the network communication wires should be shielded or install an antenna outside the car (not in the rear window). Guess what I had to do next to make the customer happy.

I also had to reroute the power wire to the rear lighter plug on one LS due to the customer plugging in his cell phone charger which sent a stray signal into the power line and cause the Air Bag light to come on setting a Restraint code.

I could figure this out if the car was in my hands, but remember no fix like this is cheap. I have to redesign the system which takes a lot of time.
 
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The four channel amp and the sub amp are both on 30A fuse F4.18 in the trunk. According to the wiring diagrams, this fuse doesn't power anything else. It's off of a bus that powers a bunch of stuff, but it's really close to the battery.
 
It appears to me the tone only emanates from the left front speaker.
 
LS4me said:
It appears to me the tone only emanates from the left front speaker.
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Doesn't the Navigaton talk through the left front speaker? May be coming through the Nav. unit.

If so route the power from the nav. unit to the battery junction box. (Use the same size fuse)

MR. H
 
The nav module (in the trunk) is powered from fuse F4.14 (10A). It's off the same bus as the four-channel amp. This fuse doesn't feed anything else.

The voice signal from the nav unit goes to the headunit via a twisted pair differential drive with a shield.
 
I recently replaced my THX nav head-unit with aftermarket. I retained the factory amps, speakers, subs, and wiring. The high pitched tone after startup is no more. Apparently, it really did originate in the THX nav head-unit or controller, not in the amps.
 
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