GS-911 and ezCAN User Forum

General Category => Technical => GS-911 => ABS related issues => Topic started by: knappen on May 01, 2020, 02:49:09 PM

Title: Measure the pressure sensor...
Post by: knappen on May 01, 2020, 02:49:09 PM
Hi there!

Does anybody here have a clue how to measure if the ABS motor pressure sensors works? i do have gs-911 and i know that there is a possibility to measure with the software, but it does not give access to it... i don´t know if it does that because mine are not totally mounted to the ABS motor unit.




Title: Re: Measure the sensors...
Post by: knappen on May 01, 2020, 02:50:46 PM
the picture
Title: Re: Measure the sensors...
Post by: mike d on May 01, 2020, 06:04:12 PM
Have a good look at the surface of the sensors, I've seen a number that had hairline fractures.

Mike
Title: Re: Measure the sensors...
Post by: Borgia on May 01, 2020, 10:42:23 PM
https://youtu.be/wnvrsY-UPf4


Sent from my SM-T813 using Tapatalk

Title: Re: Measure the sensors...
Post by: knappen on May 01, 2020, 11:46:15 PM
ooh thanks for the reply but i did not mean the abs wheel sensors... sorry if i was unclear. That was still good information :)

I did mean the ABS motor Unit (iABS III BMW) inside there is 2 sensors. I attached also a picture of the sensors.
Title: Re: Measure the sensors...
Post by: Borgia on May 02, 2020, 12:22:22 AM
My mistake.
Title: Re: Measure the pressure sensor...
Post by: knappen on May 03, 2020, 02:06:16 PM
i did try to measure the pressure sensors but i don´t know what the values mean...
Ohm and  200K

Old White:                                     NEW White:
Blue + second cable = 15.8             Blue + second cable = 33.8
Blue + 3:rd cable = 5.2                   Blue + 3:rd cable = 5.3
Blue + 4 = 29.9                              Blue + 4 = 21.3
Blue + 5 = 0                                   Blue + 5 = 0
Blue + 6 = 0                                   Blue + 6 = 0
Blue + 7 = 0                                   Blue + 7 = 0


Old Black:                                       NEW Black:
Blue + second cable = 34.6              Blue + second cable = 33.7
Blue + 3:rd cable = 7.5                    Blue + 3:rd cable = 5.2
Blue + 4 = 31.3                               Blue + 4 =30.9
Blue + 5 = 0                                    Blue + 5 = 0
Blue + 6 = 0                                    Blue + 6 = 0
Blue + 7 = 0                                    Blue + 7 = 0


Seams like the old white blue+2 value are to low... and on the NEW white the Blue+4 value are lower than the others.

Maybe that is why the don´t work. I will try to solder the old Black to the Old white Cable.

Title: Re: Measure the pressure sensor...
Post by: knappen on May 05, 2020, 10:27:54 AM
Are they both broken?

I will attache a picture from the test, with the same ABS unit but 2 different sensors.
This one is hanging outside ABS unit loose and the when i press the rear foot brake the ABS motor hangs and i have to shut down the power.


Fault code with this one:
24972
Pressure in rear wheel circuit too high

Title: Re: Measure the pressure sensor...
Post by: knappen on May 05, 2020, 10:32:28 AM
from second hand unit, only  changed the sensor but the same ABS Unit.
This one i mounted inside the ABS unit and the system is liquid filled and i have done the bleeding.
When i press the foot brake nothing happens...

I do get a different fault codes also.

25072 : Faulty ADC value of rear speed sensor
Currently present : YES
|
24955 : Internal control module error - Analogue value, rear pressure sensor
Currently present : YES
|
25193 : Brake fluid level too low
Currently present : YES
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 05, 2020, 11:33:00 AM
Yes Knappen, unfortunately they are both faulty.

Have a look at these values.  They should be around 20 - 25Bar.  I have only indicated the one value, but the one above it is also too high.  Both of these values are for the wheel circuit, which means that both the sensors on the same unit (the one with the long cable) are faulty.  I do note though that you have a brake fluid low warning, which could complicate matters.  Fill the fluid correctly and then try again.

(https://i.imgur.com/sQbVNeL.jpg)

On the other module, this value is "0 Bar", which would indicate that it too is faulty (Also the wheel circuit, also the unit with the long cable)

(https://i.imgur.com/pWDCujh.jpg)

In your photo you posted, this is how the sensors are laid out.

(https://i.imgur.com/A4TIrof.jpg)

If it helps, this is how the pump is divided.

(https://i.imgur.com/6RuXEv6.jpg)

So from the second pic above "Pressure wheel circuit Rear" would refer to the sensor that is located in the Rear wheel circuit quadrant (Bottom Left) of the pic above.
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 05, 2020, 11:42:46 AM
Just another thought.  When you change the pump over, swap the control unit.  In other words, use the same control unit that belongs in your bike for both pumps.
Title: Re: Measure the pressure sensor...
Post by: knappen on May 05, 2020, 01:28:20 PM
Hi Jughead and thanks for the reply!

I have use the control unit that belongs to my bike for both of the ABS pumps... the second hand control unit (the one with the big connection) did not work or respond at all.

I tried another combination:
The short one (with black socket) from my bike and the long one ( with white socket) with the second hand unit.

I have hard time to figure out witch ones are broken lol
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 05, 2020, 01:41:08 PM
Hi Jughead and thanks for the reply!

I have use the control unit that belongs to my bike for both of the ABS pumps... the second hand control unit (the one with the big connection) did not work or respond at all.

I tried another combination:
The short one (with black socket) from my bike and the long one ( with white socket) with the second hand unit.

I have hard time to figure out witch ones are broken lol

Green circles are 100%
Red arrow is the faulty one.


(https://i.imgur.com/Ie88YJq.jpg)

(https://i.imgur.com/MFjojXP.jpg)
Title: Re: Measure the pressure sensor...
Post by: knappen on May 05, 2020, 02:03:41 PM
So the one with long cables are broken and 1 black one is okay... the other black one might be okay?  there is a difference one value 10.07 and the other 22.65 so it might work or maybe not... right?
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 05, 2020, 02:17:52 PM
So the one with long cables are broken and 1 black one is okay... the other black one might be okay?  there is a difference one value 10.07 and the other 22.65 so it might work or maybe not... right?

Yes!

How well can you solder?

What you can try is to cut the long cable off about 50mm from the sensor end.  Then cut the short cable off the spare sensor at the same point and solder the long cable onto the spare sensor.  Just use heatshrink to insulate the solder joints.

(https://i.imgur.com/LDNzWzY.jpg)
Title: Re: Measure the pressure sensor...
Post by: knappen on May 05, 2020, 02:34:48 PM
Okay... and cross my fingers right?  ::)

Do i need any silicone to seal, or is it okay to reuse the rubber seal?
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 05, 2020, 03:53:11 PM
Okay... and cross my fingers right?  ::)

Do i need any silicone to seal, or is it okay to reuse the rubber seal?

To seal what?
Title: Re: Measure the pressure sensor...
Post by: knappen on May 05, 2020, 04:33:10 PM
aah... sorry... i do mean the sensor on the outside ( the one with long cable ) there is a black rubber seal, can i reuse the rubber seal for it to be totally sealed?


Title: Re: Measure the pressure sensor...
Post by: Jughead on May 05, 2020, 08:32:24 PM
aah... sorry... i do mean the sensor on the outside ( the one with long cable ) there is a black rubber seal, can i reuse the rubber seal for it to be totally sealed?

Yes you can.  No silicon required.
Title: Re: Measure the pressure sensor...
Post by: knappen on May 06, 2020, 10:29:37 AM
Did solder it my self.. it ain't pretty but i work and the ABS pump gives no warning lights.
I do have some faultcodes in memory but it says NO under the fault.

But big THANKS for the HELP !  :)



Title: Re: Measure the pressure sensor...
Post by: Jughead on May 06, 2020, 10:38:34 AM
Did solder it my self.. it ain't pretty but i work and the ABS pump gives no warning lights.
I do have some faultcodes in memory but it says NO under the fault.

But big THANKS for the HELP !  :)

Awesome!  Congrats!  ;D [emoji106]
Title: Re: Measure the pressure sensor...
Post by: knappen on May 06, 2020, 10:45:55 AM
Thanks...  But i could not have done it without your help  ;)

The bike is together now and the brakes works fine  :)
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 06, 2020, 11:04:02 AM
Thanks...  But i could not have done it without your help  ;)

The bike is together now and the brakes works fine  :)

[emoji106]  Glad to be of assistance.
Title: Re: Measure the pressure sensor...
Post by: knappen on May 18, 2020, 11:21:06 AM
so i found another ABS pump and took out the sensors... did some measurement, what do you think about these values?

 
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 18, 2020, 12:09:04 PM
Front wheel sensor looks a little high, but you now know how to resolve that issue,  ;D
Title: Re: Measure the pressure sensor...
Post by: knappen on May 18, 2020, 12:16:35 PM
Well i guess that you are right... just do it right the first time 😀
Title: Re: Measure the pressure sensor...
Post by: knappen on May 18, 2020, 02:21:15 PM
i did solder it and now it does not work on the rear... there is no power to it...  :(
Do you have a solution for this?

It work fine when i tested it first, the values was fine but after the soldering something happened...
It seems like the electronic board(computer/circuit board) does not work all the time, it gives power sometimes and sometimes not

Title: Re: Measure the pressure sensor...
Post by: knappen on May 22, 2020, 08:38:27 AM
so.. still fighting with my abs

Having fault codes but it comes and goes it says:
24971
Pressure in front wheel circuit too high
The fault is not present now.


but the values are perfect. Could this comes from air in the system?

Title: Re: Measure the pressure sensor...
Post by: Jughead on May 22, 2020, 08:56:53 AM
It is possible that you have an intermittent problem with the sensor.  It senses pressure too high, logs the error code, then returns to normal by the time you take the readings.
Title: Re: Measure the pressure sensor...
Post by: knappen on May 22, 2020, 09:54:11 AM
so what shall i do? change the sensor.. change the ABS pump? or try to bleed the system again?   :-\ :'(
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 22, 2020, 11:30:21 AM
Yoh!  Difficult question.  Unfortunately with these pumps it is very much a matter of trial and error.  I would replace the sensor to start with.
Title: Re: Measure the pressure sensor...
Post by: knappen on May 22, 2020, 11:52:34 PM
i replaced the whole ABS unit/pump i hade a used one...

But now i wonder how does the Bleeding work with the GS-911?  I run the software... right? But do i have to open any nipple to let the air out... if so... witch one? The ones on the wheels or on the ABS unit( witch one of the 6 ? )
Title: Re: Measure the pressure sensor...
Post by: mike d on May 23, 2020, 11:15:49 AM
The GS-911 Bleed test is just that. A test to see if you have any trapped air in the system AFTER you performed the physical bleed operation.

The following is just one of a number of explanations on how to perform the actual bleed sequence.

https://www.ukgser.com/technical/nick/Brake%20bleeding%20(All%20BMW%20EVO%20systems,%20%2704-%2707).pdf

Mike
Title: Re: Measure the pressure sensor...
Post by: Jughead on May 25, 2020, 06:49:10 AM
The GS-911 Bleed test is just that. A test to see if you have any trapped air in the system AFTER you performed the physical bleed operation.

The following is just one of a number of explanations on how to perform the actual bleed sequence.

https://www.ukgser.com/technical/nick/Brake%20bleeding%20(All%20BMW%20EVO%20systems,%20%2704-%2707).pdf

Mike

Agreed.  This is one of the best write-ups for bleeding these systems.
Title: Re: Measure the pressure sensor...
Post by: knappen on May 25, 2020, 04:06:15 PM
okay thanks guys for the help :)