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1Back to top Go down   Hall sensor - ECU problem ? Empty Hall sensor - ECU problem ? on Thu Jul 23, 2020 11:05 am

oote

oote
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Hi all, Motor k100rs from end 1984. 

While driving my motor dropped dead. Fuel - good !, ignition problem ... - cylinder 2-3 no spark on the plugs. Coil lead switched tells me that it is the lead and not the coil itself.
Did measure all the cables in the ignition system for a broken wire or a short. No problems to find. 
Hall sensor and ECU not jet replaced as symptoms are a little more complex.  I thought that the engine should stay running when only two cylinders work - correct ?  Also, the starter motor does crank but not full power, gives a few cranks and I need to push the starter button again. Battery is good as it works properly on my other k100 motor. Also checked the brushes on starter motor - still as new, almost 12 mm long on the edges.
To exclude everything before I swap Hall sensor and ECU what wiring and/or relay I should measure ?
What could be the problem ? Or is it simple that the ECU causes the starter to crank difficult.
Thanks for your suggestions.

    

2Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Thu Jul 23, 2020 5:15 pm

92KK 84WW Olaf

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If starter is weak and battery is fully charged possibly brushes or other problem in it. Brush kit OEM is cheap.


__________________________________________________
1992 K100LT 0193214 Bertha Alaska Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 105,200 miles
1983 K100RS 0011171 Fricka 606 29,495 miles Damn K Pox Its a Bat outta Hell Now 36,188  miles
    

3Back to top Go down   Hall sensor - ECU problem ? Empty No go on Thu Jul 23, 2020 5:51 pm

daveyson

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Hi Oote,

Which leads were swapped, and what happened after that?

It's probably too early to say, but a simple hall sensor test is shown with photos on the thread "Starter issues - K100RS"


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
    

4Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Thu Jul 23, 2020 9:16 pm

RicK G

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The injection gets i signal to fire from the hall sensor for cylinders 2-3 so that is why it wont fire even on 2 cylinders. Start by checking the hall sensors there is a how to on this subject


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

5Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Wed Jul 29, 2020 5:15 pm

oote

oote
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@RicK G wrote:The injection gets i signal to fire from the hall sensor for cylinders 2-3 so that is why it wont fire even on 2 cylinders. Start by checking the hall sensors there is a how to on this subject

Thanks Rick and also the others for the trouble shooting suggestions. Helpful ! I replaced today the ICU. First just plugged it in and got again a spark on c2-3. Put it all together and again no spark... So I again took of the tank and rechecked all the wiring for a loose contact or break to the ICU. No problem in the wiring to find. Starter-motor with this other ICU does turn over normal.
I was wondering is there a relay that could cause the ICU to malfunction or even to break down after one of two short engagements on the C 2-3 ICU internals?    Thanks in advance for your input.

    

6Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Thu Jul 30, 2020 2:54 am

oote

oote
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@92KK 84WW Olaf wrote:If starter is weak and battery is fully charged possibly brushes or other problem in it. Brush kit OEM is cheap.
Richard Metz wrote that the ground of the starter is going through the ICU.

"You’d think the ground side of the relay would be wired directly to a chassis ground, as it is on many machines, but this is not the case on the K100. In fact the ground is provided thru the ignition brain and on thru the HES!!!! That’s why an intermittent HES problem causes on-off-on-off starter operation with the starter button held down."  https://ibmwr.org/index.php/1998/04/01/starter-electrical-problems/

By switching the ICU the weak starter symptoms went away. Now still having the c 2-3 spark problem to solve....

    

7Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Thu Jul 30, 2020 9:48 am

Laitch

Laitch
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@oote wrote:To exclude everything before I swap Hall sensor . . .
Test the Hall sensors first. Have you found the test in the Portal's Tech Page section in the category Testing the Hall Sensors?


__________________________________________________
1995 K75 77,000 miles
Hall sensor - ECU problem ? Usa-lo10
    

8Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Sat Aug 01, 2020 12:38 pm

oote

oote
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I have 3 Hall’s and did do three test: Ohm / Volt / Amp


test 1- Ohm

  —  reading works only when negative of the ohm meter is on pin 4  and + on pin 3
( Pin coding is as ‘Bert 2009’  -  https://servimg.com/view/20230085/9 )

Sensor 1: unblocked and blocked*

4-3   zero Ohm /  no resistance

4-5   2.5K Ohm   

4-2   2.5K Ohm  



Sensor 2: unblocked and blocked

4-3   100% resistance

4-5    2.5 Kohm

4-2   100% resistance



sensor 3: unblocked and blocked

4-3   2.5K Ohm

4-5   2.5K Ohm

4-2   2.5K Ohm



* No difference between unblocked and blocked sensors makes sense as the ohm meter does not activate the sensors, it just measures the internal resistance of the sensor.




test 2 - Volt

sensor 1 unblocked  - 12 volt  (with is correct with the LED test light ‘on’ as it means there is a voltage)

sensor 2  - zero / no voltage

sensor 3 unblocked  - 12 volt



I conclude sensor 2 is broken.



test 3 - mAmp  (This test compared to the ohm readings becomes interesting for me.)

sensor 1 , my meter max out at 150mA , de arrow goes all the way in the corner.

sensor 2 / 0 mAmp

sensor 3  about 20 mAmp




I made a short cranking with the replacement ICU to test or it all worked, I got a spark so concluded hall sensor is good but when starting up the motor for real and it would not start having again no spark on cylinder 2-3 (The coil is good)



Is it possible that sensor 1 has broken the ICU because it sends a to high mAmp through the ICU circuit ?
( Why only the circuit of c 2-3 ?)

Anybody has had that problem to ? 

Is my diagnostic reasoning correct ?

I will replace this time both Hall sensor and again the ICU…. 
 Twisted Evil

    

9Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Sat Aug 01, 2020 1:35 pm

Laitch

Laitch
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@oote wrote:I will replace this time both Hall sensor and again the ICU…. 
 Twisted Evil
If your intention is to replace the Hall sensor i]first[/i] then try starting the engine, that is a useful strategy.

If your intention is to replace both before trying to start the engine, that won't indicate which was faulty until they are tested in the engine separately.


__________________________________________________
1995 K75 77,000 miles
Hall sensor - ECU problem ? Usa-lo10
    

10Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Sat Aug 01, 2020 2:02 pm

oote

oote
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I did not know what was faulty and as the Hall sensor worked / got a spark by test cranking ! I assumed the Hall sensor is okay.
The LED light test does not take the amp overload between ICU and the hall sensor in consideration. If you look at my test my sensor looks to be okay. Also, and very important, I can not find fault tests on Amp 'communication' between the hall sensors and the ICU. I am eager to know and I want to make sure before I go replacing further parts that the Amp overload is what causes the ICU to break down.

Can you please do the ohm / Amp test on a hall sensor, pins 4-3, and post your results ?
Your not helping me only, there must be more people out there with the same diagnostic problem.
Thanks in advance.

    

11Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Sat Aug 01, 2020 2:28 pm

Laitch

Laitch
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@oote wrote: I assumed the Hall sensor is okay.
Thanks in advance.
You shouldn't need to assume anything; knowing is better. You've made your description of this test more complicated than I can comprehend on a Saturday. How about trying this test description from the troubleshooting guide?

Any good sensor should light the LED until something metallic, like a feeler gauge, is introduced in to the sensors gap, the LED will then go out.
 
Any sensor that doesn't light the LED or doesn't go out when the sensor gap is obstructed is defective.


__________________________________________________
1995 K75 77,000 miles
Hall sensor - ECU problem ? Usa-lo10
    

12Back to top Go down   Hall sensor - ECU problem ? Empty Hall - ICU problem SOLVED ! on Sat Aug 08, 2020 6:23 am

oote

oote
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Motor is fixed and drives again !  3 Hall's and 3 ICU later... 

My Hall (#1)was good according the LED test but did not work under normal working condition as posted before. Although my old Hall was not broken doing the LED test and sparked by short test (looking at the sparkplug and a short cranking), under load it stopped the ICU from functioning. That has thrown me off as my diagnostic conclusion told me I burned two ICU's. When I finally placed the Hall that measured 2.5kOhm on all pins, all three the ICU worked normal.
Why the ICU stop functioning normal on my old Hall I do not know. My conclusion from doing the various tests is that there was to many mAmp between pin 4-3.
I searched study or there is an Amp overload protection within the ICU but did not find information on it.
Hope this of help to the next person with the same problem.
Happy riding ! Very Happy

    

13Back to top Go down   Hall sensor - ECU problem ? Empty Re: Hall sensor - ECU problem ? on Sat Aug 08, 2020 9:38 am

Laitch

Laitch
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Life time member
cheers


__________________________________________________
1995 K75 77,000 miles
Hall sensor - ECU problem ? Usa-lo10
    

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