Power steering control unit causing constant buzzing?
05-15-08 | 07:08 AM
#1
Thread Starter
Junior Member
Joined: Oct 2004
Posts: 13
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From: Guelph, Ontario
Power steering control unit causing constant buzzing?
'87 NA
Just wondering if anyone has had this problem. I think I have narrowed it down to the control unit or the stepping motor, maybe a short somewhere.
Any hints would be great.
Also spongy breaks, dont hold pressure.
Brand new poly break lines, rebuilt calipers, bled many times.
Master brake cylinder or brake booster?
Any help would also be beneficial.
Just wondering if anyone has had this problem. I think I have narrowed it down to the control unit or the stepping motor, maybe a short somewhere.
Any hints would be great.
Also spongy breaks, dont hold pressure.
Brand new poly break lines, rebuilt calipers, bled many times.
Master brake cylinder or brake booster?
Any help would also be beneficial.
05-15-08 | 07:44 AM
#2
Welcome to the forum. The search button will become your best friend.
The buzz from the Power steering is fairly common, do a search and you will find the fix. I honestly don't remember what it is off the top of my head but i know it's been covered mutiple times.
If your breaking system is loosing fluid and there is no visiable leak in the lines or at the calipers, the rear seal in the Master is probably shot. Replace it and make sure you empty the brake booster while it is off. If the system is not loosing fluid, they probably just need to be bled.
The buzz from the Power steering is fairly common, do a search and you will find the fix. I honestly don't remember what it is off the top of my head but i know it's been covered mutiple times.
If your breaking system is loosing fluid and there is no visiable leak in the lines or at the calipers, the rear seal in the Master is probably shot. Replace it and make sure you empty the brake booster while it is off. If the system is not loosing fluid, they probably just need to be bled.
05-15-08 | 11:22 AM
#3
Former Moderator. RIP Icemark.
Joined: Apr 2001
Posts: 25,896
Likes: 20
From: Rohnert Park CA
The things that cause a constant buzzer and not beeping are:
low oil
low coolant
over-rev (exceeding redline)
Also spongy breaks, dont hold pressure.
Brand new poly break lines, rebuilt calipers, bled many times.
Master brake cylinder or brake booster?
Brand new poly break lines, rebuilt calipers, bled many times.
Master brake cylinder or brake booster?
So you probably have a bad master or air in the system, or cheap *** brake lines or cheap *** brake pads.
05-15-08 | 12:10 PM
#4
Thread Starter
Junior Member
Joined: Oct 2004
Posts: 13
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From: Guelph, Ontario
Yes, you are right it is a constant high pitch beep noise. I know it is the power steering because once the CU was unplugged the noise was gone, but now do not have power steering obviously.
Do you know if the P/S CU's often go bad?
I have the diagnosis check, it says with the constant "beep" noise would be the stepping motor (possible short in coil) or the CU itstelf.
Next thing would be to find a spare CU to try it.
As for the brakes, thanks I can now eliminate the booster as the problem child.
Brake pads will not cause a spongy feeling at the pedal regardless if they are "cheap ***".
And no the brake lines are not cheap *** either. Just mentioned those facts to narrow the thought process.
So Im thinkin the master cylinder seal is buggered.
The help is much appreciated, any more hints?!
Do you know if the P/S CU's often go bad?
I have the diagnosis check, it says with the constant "beep" noise would be the stepping motor (possible short in coil) or the CU itstelf.
Next thing would be to find a spare CU to try it.
As for the brakes, thanks I can now eliminate the booster as the problem child.
Brake pads will not cause a spongy feeling at the pedal regardless if they are "cheap ***".
And no the brake lines are not cheap *** either. Just mentioned those facts to narrow the thought process.
So Im thinkin the master cylinder seal is buggered.
The help is much appreciated, any more hints?!
05-15-08 | 12:34 PM
#5
Former Moderator. RIP Icemark.
Joined: Apr 2001
Posts: 25,896
Likes: 20
From: Rohnert Park CA
Yes, you are right it is a constant high pitch beep noise. I know it is the power steering because once the CU was unplugged the noise was gone, but now do not have power steering obviously.
Do you know if the P/S CU's often go bad?
I have the diagnosis check, it says with the constant "beep" noise would be the stepping motor (possible short in coil) or the CU itstelf.
Next thing would be to find a spare CU to try it.
Do you know if the P/S CU's often go bad?
I have the diagnosis check, it says with the constant "beep" noise would be the stepping motor (possible short in coil) or the CU itstelf.
Next thing would be to find a spare CU to try it.
The FAQ for FC sticky thread found at the top of this section covers the beeps and what each set means.
As for the brakes, thanks I can now eliminate the booster as the problem child.
Brake pads will not cause a spongy feeling at the pedal regardless if they are "cheap ***".
Brake pads will not cause a spongy feeling at the pedal regardless if they are "cheap ***".
Switch between a metallic and a ceramic pad and then come back and tell me there is no difference.
And no the brake lines are not cheap *** either. Just mentioned those facts to narrow the thought process.
So the $100 ebay special stainless steel brake lines are often not worth half the money (hence my cheap *** term) as they have that problem.
So Im thinkin the master cylinder seal is buggered.
The help is much appreciated, any more hints?!
The help is much appreciated, any more hints?!
05-15-08 | 05:52 PM
#6
Thread Starter
Junior Member
Joined: Oct 2004
Posts: 13
Likes: 0
From: Guelph, Ontario
Thanks Icemark,
Ok so what is this FC sticky thread?
I went to FAQ at the top and did not return any matches, probably not going where you said.
But like I said, there is no pause...it's constant annoying high pitch beeping. From what I have found, the cause is the CU unit or stepping motor.
I get what you mean between metallic and ceramic pads.
Pedal goes basically right to the floor with no resistance but will stop the car eventually.
I will try the check of each line for swelling next time I get a chance.
I did get the brake lines replaced professionally by a mechanic who used to work for Mazda.
Is there a way to check the master before removing it?
Ok so what is this FC sticky thread?
I went to FAQ at the top and did not return any matches, probably not going where you said.
But like I said, there is no pause...it's constant annoying high pitch beeping. From what I have found, the cause is the CU unit or stepping motor.
I get what you mean between metallic and ceramic pads.
Pedal goes basically right to the floor with no resistance but will stop the car eventually.
I will try the check of each line for swelling next time I get a chance.
I did get the brake lines replaced professionally by a mechanic who used to work for Mazda.
Is there a way to check the master before removing it?
05-16-08 | 01:01 AM
#7
The Blue Blur
Joined: Dec 2006
Posts: 716
Likes: 0
From: Virginia
ah, yeah, see I have seen more bad brake lines than anything else, cause a mushy pedal. Particularly if the lines were stainless steel braided or teflon core. Both if improperly crimped will leak internally in the line between the layers. The only way to see this is if the line finally pops, or you have someone press the pedal down hard while you physically touch and check each line for swelling.
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05-16-08 | 11:27 AM
#8
Former Moderator. RIP Icemark.
Joined: Apr 2001
Posts: 25,896
Likes: 20
From: Rohnert Park CA
There currently are 4 sticky threads there. They contain all sorts of info including the FAQ for FC, as well as the 10th Anniversary Edition registration, the What did my car come with thread, and the how to use the forum thread.
But like I said, there is no pause...it's constant annoying high pitch beeping. From what I have found, the cause is the CU unit or stepping motor.
From the FAQ for FC:
Originally Posted by FAQ for FC
I keep hearing a beep beep beep
Probably the power steering computer telling you there is a problem with the system. The number of beeps before pausing will indicate the problem.
1-beep, pause, repeat - in case abnormality of speed sensor signal:
In case broken wires or short circuits occur to sensors or harnesses, the buzzer sounds 60-seconds after the engine speed signal of 2200 rpm continues for 18-seconds.
2-beeps, pause, repeat - in case abnormality of engine speed signal:
The buzzer sounds twice and repeats when the vehicle speed signal is missing input and/or no engine speed signal is found (short circuit, broken wire, etc.)
3-beeps, pause, repeat - in case abnormality of stepping motor signal:
The buzzer sounds when there are broken wires or short circuits in coils or harnesses.
4-beeps, pause, repeat - in case abnormality of the power steering microcomputer:
The buzzer sounds 4 and repeats when there are circuit troubles other than with the micro computer.
5-beeps, pause, repeat - in case abnormality of steering sensor signal: Steering sensor is mis-aligned or failed or steering wheel has been improperly installed.
Probably the power steering computer telling you there is a problem with the system. The number of beeps before pausing will indicate the problem.
1-beep, pause, repeat - in case abnormality of speed sensor signal:
In case broken wires or short circuits occur to sensors or harnesses, the buzzer sounds 60-seconds after the engine speed signal of 2200 rpm continues for 18-seconds.
2-beeps, pause, repeat - in case abnormality of engine speed signal:
The buzzer sounds twice and repeats when the vehicle speed signal is missing input and/or no engine speed signal is found (short circuit, broken wire, etc.)
3-beeps, pause, repeat - in case abnormality of stepping motor signal:
The buzzer sounds when there are broken wires or short circuits in coils or harnesses.
4-beeps, pause, repeat - in case abnormality of the power steering microcomputer:
The buzzer sounds 4 and repeats when there are circuit troubles other than with the micro computer.
5-beeps, pause, repeat - in case abnormality of steering sensor signal: Steering sensor is mis-aligned or failed or steering wheel has been improperly installed.
So if unplugging the power steering computer does solve the issue of the beep, then you just are not counting or the speedo cable is not hooked up to the speedometer in the dash or the tranny.
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