Warning sound & ABS light flashing

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shanester

shanester

10 Year
Joined
Oct 11, 2011
Threads
46
Messages
242
Location
San Diego, CA
I was loading up my family for lunch today when we heard what sounded like a high pitched & constant warning sound coming from inside the vehicle. The car was off at this point and the sound wasn't loud but it was annoying. I've never heard this sound since owning the vehicle which has been for about 4 months now (02' LC). I started the car and the sound went away.

The vehicle drove fine to the restaurant. We ate our meal and as soon as we opened the door, there was the sound again. I start the car and again, it goes away. I noticed the ABS light flickering, but it wasn't constant. It would flicker at a stop light, flicker a little while driving, and then it was gone. This happened for the first 5 minutes of driving then it went away (unless I missed it while paying attention to the road).

Any idea on what is going on here?
 
The computer will warn you - that constant "alarm" sound - when your ABS is in the process of failing. I'm not saying that's what's happening with yours, but... it does sound very familiar. I got the flashing light(s) on the dash with that constant tone. Then it went away. It happened 4 or 5 times. Then, the power brakes went out completely. The fix was a new master cylinder, pump, computer... Actually, I'm not sure which of the parts were swapped... but one of them had a comma in the price.

Again, this may not be what's going on with your 100. This topic has been discussed a few times. It's worth a search and some reading. Look for "ABS Failure" and things related
 
Manhattan said:
The computer will warn you - that constant "alarm" sound - when your ABS is in the process of failing. I'm not saying that's what's happening with yours, but... it does sound very familiar. I got the flashing light(s) on the dash with that constant tone. Then it went away. It happened 4 or 5 times. Then, the power brakes went out completely. The fix was a new master cylinder, pump, computer... Actually, I'm not sure which of the parts were swapped... but one of them had a comma in the price.

Again, this may not be what's going on with your 100. This topic has been discussed a few times. It's worth a search and some reading. Look for "ABS Failure" and things related
Click to expand...

Yikes - that is absolutely not what I wanted to hear. Reading up on this now but please post any thoughts/experiences if you have any.
 
Could be the ABS pump or accumulator. There is a number of threads here on what happens if it's one of those things. For me, it came on, I lost pedal pressure. It should also throw a code, so you might want to see if you have one. That would give a better clue.

For me the accumulator couldn't be separated from the master cylinder due to corrosion, so I ended up with a whole new master cylinder, abs and accumulator assembly. Not cheap. But hey it's your brakes!
 
Just called my local LC shop and they confirmed what you both have said. I spoke to the owner and he said to keep an eye on it for now and if the brakes start to feel out of the ordinary, then to take it in. He also confirmed that it's a $2K+ job. This couldn't be happening at a worse time with my wife and I's 6th anniversary road trip at the end of the month.

I have to wonder if any of this has to do with the truck getting stuck in the mud last week. Seems almost too coincidental. My truck only has 106,000 miles on it.
 
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Not a good month for you, man. The fact that you are getting the alarm to sound while you are parked and have doors and such open is of interest. You are the first, that I have read, that has posted this scenario. Most of the other posts I have read the alarm and lights have flashed or stayed on while the person has been driving. Since you got stuck in Salton Sea, deep, and had issues with vibrations and noises I believe there is some correlation to the vehicle issues you are experiencing. If I were to guess what may be your issue I would say it may be a wheel/abs sensor. You damaged the sensor or you have something causing issues with the connection.

As others have claimed yes there is a loss of brakes if the above components are the issue.
Don't have your family cruise in the truck until you have ruled some stuff out. Let's see what others chime in with.
 
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OG 91 LC said:
Not a good month for you, man. The fact that you are getting the alarm to sound while you are parked and have doors and such open is of interest. You are the first, that I have read, that has posted this scenario. Most of the other posts I have read the alarm and lights have flashed or stayed on while the person has been driving. Since you got stuck in Salton Sea, deep, and had issues with vibrations and noises I believe there is some correlation to the vehicle issues you are experiencing. If I were to guess what may be your issue I would say it may be a wheel/abs sensor. You damaged the sensor or you have something causing issues with the connection.

As others have claimed yes there is a loss of brakes if the above components are the issue.
Don't have your family cruise in the truck until you have ruled some stuff out. Let's see what others chime in with.
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Yes and I'd just like to reiterate that the alarm sound does goes away as soon as I start the car. There are no sounds while driving and just 2-5 ABS flickers spastically during the first minute of driving. When I reach my destination and turn off the car and pull the key out, the alarm sounds. Another strange thing that happened was the alarm turned off when I manually locked all doors.

I will check the wheel/abs sensor like you mentioned (more research to do to figure exactly how to do it). Thanks guys.
 
My understanding from a reputable shop here in ATL is this is your warning. Eventually the sound will come on and you will have no brakes, period.
 
shanester said:
Yes and I'd just like to reiterate that the alarm sound does goes away as soon as I start the car. There are no sounds while driving and just 2-5 ABS flickers spastically during the first minute of driving. When I reach my destination and turn off the car and pull the key out, the alarm sounds. Another strange thing that happened was the alarm turned off when I manually locked all doors.

I will check the wheel/abs sensor like you mentioned (more research to do to figure exactly how to do it). Thanks guys.
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Alarm turns on when the ignition is off + alarm turns off when doors locked suggests to me you've got a moisture ingress issue. Did you pressure wash to get rid off all the mud?
 
PADDO said:
Alarm turns on when the ignition is off + alarm turns off when doors locked suggests to me you've got a moisture ingress issue. Did you pressure wash to get rid off all the mud?
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Yes I pressure washed the absolute hell out of it. Are you saying moisture might have gotten to the ABS sensor?
 
@shanester, I'd not panic yet... you're getting very similar beeps, lights, etc. But... BUT, they're not exactly the same. Do you have access to an independent Toyota shop? Someone who really knows these trucks?
 
@shanester In saying the behavior you're describing doesn't fit any of the normal criteria for the ABS light and warning alarm to activate, based on the ABS systems' diagnostic matrix. I mean for the alarm to sound when you turn the ignition off is non sensical and just plain dumb - and when ECUs are affected by moisture or get corrupt inputs they tend to do dumb things. I'd look for moisture ingress and use dewatering/contact cleaner spray on brake system related connectors, the MC module, ABS ECU etc. If you can access it try cleaning it. Have you checked for codes? That may narrow your search. Re "ABS sensor" there isn't an ABS sensor as such, there are multiple inputs to the ABS system and its warning ccts including wheel speeds, mc and accumlator pressures, accumulator motor current, ecu memory failure etc etc.
 
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Manhattan said:
@shanester, I'd not panic yet... you're getting very similar beeps, lights, etc. But... BUT, they're not exactly the same. Do you have access to an independent Toyota shop? Someone who really knows these trucks?
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Yeah I have a great shop about 20 minutes away. The owner owns a 100 and they're experts on LC's/LX's. I will exhaust all DIY options first (pun intended).

PADDO said:
@shanester In saying the behavior you're describing doesn't fit any of the normal criteria for the ABS light and warning alarm to activate, based on the ABS systems' diagnostic matrix. I mean for the alarm to sound when you turn the ignition off is non sensical and just plain dumb - and when ECUs are affected by moisture or get corrupt inputs they tend to do dumb things. I'd look for moisture ingress and use dewatering/contact cleaner spray on brake system related connectors, the MC module, ABS ECU etc. If you can access it try cleaning it. Have you checked for codes? That may narrow your search. Re "ABS sensor" there isn't an ABS sensor as such, there are multiple inputs to the ABS system and its warning ccts including wheel speeds, mc and accumlator pressures, accumulator motor current, ecu memory failure etc etc.
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@PRADDO Yeah, it's very dumb. As of today, no alarm sounds - nothin. Everything is back to normal but that's when others have said the brakes go out so I'm crossing fingers. I tried to google search "dewatering contact cleaner spray" and didn't get great results. Is there a specific product you can recommend? Again - I so appreciate all of the help on this forum. I have a lot to pay forward right now.
 
CRC Wire Dryer @$5 from autozone will work, or you could try any of the aerosol type electronic/connector/moisture displacing type cleaners. WD 40 and CRC make several. Hopefully if it was moisture inducing the random buzzer activation and flickering light its dried out now and resolved itself. I posted a screen shot in the mega brake failure poll thread iirc (or maybe it was one of the spinoff brake booster threads) that shows the real fault conditions that will activate the buzzer and/or light by design, it might give you an idea of what fault conditions are monitored by the system. Most definitely if you hit one of these real faults (with buzz and/or light) it must be investigated and rectified immediately.
 
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PADDO said:
CRC Wire Dryer @$5 from autozone will work, or you could try any of the aerosol type electronic/connector/moisture displacing type cleaners. WD 40 and CRC make several. Hopefully if it was moisture inducing the random buzzer activation and flickering light its dried out now and resolved itself. I posted a screen shot in the mega brake failure poll thread iirc (or maybe it was one of the spinoff brake booster threads) that shows the real fault conditions that will activate the buzzer and/or light by design, it might give you an idea of what fault conditions are monitored by the system. Most definitely if you hit one of these real faults (with buzz and/or light) it must be investigated and rectified immediately.
Click to expand...

Gotcha, thanks. I might need a little help figuring out exactly what to hit when you say I should spray the "brake system related connectors, the MC module, ABS ECU etc."

Brake system related connectors seems simple enough. Is there anything behind the wheels that would require me taking them off that I should spray? Do I need to unscrew anything? Disconnect anything? I'm assuming I shouldn't just be hitting the surface with spray.

Is the MC module directly under the MC? Again, should I start disconnecting things, spraying, and reconnecting?

For the ABS ECU, as I researching my issue I think I remember seeing a thread describing how to get to the ABS ECU with pictures. You do this from inside the vehicle correct?

You also said "etc." Can you elaborate? Thanks @praddo.
 
Just wanted to close out this thread in hopes that documenting my intermittent alarm sound can help someone in the future who might have similar issues. I suspect it was indeed what PADDO said it might be because I've driven the truck everyday since starting this thread and haven't had a single issue with my brakes. The truck is running excellent and the alarm hasn't sounded in weeks.

From @PRADDO:

"In saying the behavior you're describing doesn't fit any of the normal criteria for the ABS light and warning alarm to activate, based on the ABS systems' diagnostic matrix. I mean for the alarm to sound when you turn the ignition off is non sensical and just plain dumb - and when ECUs are affected by moisture or get corrupt inputs they tend to do dumb things. I'd look for moisture ingress and use dewatering/contact cleaner spray on brake system related connectors, the MC module, ABS ECU etc. If you can access it try cleaning it. Have you checked for codes? That may narrow your search. Re "ABS sensor" there isn't an ABS sensor as such, there are multiple inputs to the ABS system and its warning ccts including wheel speeds, mc and accumlator pressures, accumulator motor current, ecu memory failure etc etc."
 
EMERGENCY! Well kinda...Just need to know where the alarm is located in the dash so I can disconnect. I've been driving the 99 LX470 for 6 months with the alarm on and no power brakes or ABS and it stops just fine now that my right thigh is thunderous.

Does anyone know where this pesky alarm speaker is located behind or under the dash? Yes I know i need to just fix that is later, this s now :)
 
if anyone knows where the alarm speaker is please post - I have similar issue - but unlike 'dirtymotorman' 6 weeks of alarm and brakes and all components check out fine - brakes are no fault at all - until there is a failure I just want to shut up the alarm
 
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