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Primary/secondary resistance specs are there.For the LTs but same as the RS/GTs.


This for an older automotive single coil but the procedure is the same.

 

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Discussion Starter #143
Ok so the retest of the coil shows that both sides are within spec for resistance.

1 - 4 shows 0.9 OHM
2 - 3 shows 0.9 OHM

I see 12 volts being fed to the coils from the middle pin of wire coming in when key switched on.

Is there any way to test the ground wires coming in from the MCU?

Thx
 

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Both my coil packs test just like that from the link I gave you.I don't know where your 0.9ohm spec comes from?

From the LT forum:

Primary resistance 0.5 ± 0.05 OHMs
Secondary resistance 13.3 ± 1.3 KOHMs
 

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Discussion Starter #145
ok Thx

So I got that from previous test in this string that I got no negative response too. Obviously that was an indication of problem on my previous test.

And Ive not completed the test per link you gave me. I'll go back and read link again and test further.
 

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Discussion Starter #146
Ok so what am i doing wrong. Have my coil here on table.

Again between connector pin 2 (positive) and 1 (negative) pin I'm getting 0.9 OHMs and between pin 2 and 3 I'm getting the same 0.9 OHMs. Primary resistance correct?

When testing between pin 2 (positive) and any of the Secondary terminals (plug wire connections) I cant seem to get a reading.
 

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Both my coil packs test just like that from the link I gave you.I don't know where your 0.9ohm spec comes from?

From the LT forum:

Primary resistance 0.5 ± 0.05 OHMs
Secondary resistance 13.3 ± 1.3 KOHMs
Just to confirm I just tested my spare coil.
Primary is 0.5 Ohms
Secondary is 13 K Ohms

Same as the one on my bike as tested years ago.

Is that the problem or not? I can't tell you.

But what I remember is the coil ground wire being kind of cooked and failing an Ohm test so I had to replace it.
 

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Had been a while...secondary is between the spark plugs wire pins:

28392

Primary pins1/2 or 2/3, you have to let the reading stabilise.This coil shows 0.6 at first but a few seconds later will go to 0.5 or even 0.4.

28391
 

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Discussion Starter #149
Thx - Perfect

So got good readings on Spare.

Then went to garage and tested unit on bike

Primary
1-2 = 0.3
2-3 = 0.3

Secondary

Between - 2 - 3 = 13.39
Between - 1 - 4 = 13.11

So those reading appear ok don't they?

If so, I suspect wiring to MCU or MCU itself at pin 33???
 

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So if I understand the coils on the bike were 0.9 and now 0.3?

Either reading is out of specs according to the LT specs and both my coils packs.

So what are the "spare" good readings? Only takes a few minutes to switch coils.
 

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Discussion Starter #151
Ok so not getting good readings. The Primary resistance readings was not "settled" and showing higher than expected.

So I took the coil off the bike and set it on the table to test.

Once connected and letting the numbers settle down.

Primary Resistance

Pin 1 to 2 = 0.6 OHMs
Pin 2 to 3 = 0.6 OHMs

* I believe the variance may be related to Multimeter.

Secondary resistance .


1 - 4 = 13.24 OHMs
2 - 3 = 13.01 OHMs

Put back together and started bike - No spark seen on Cyl 2. Stopped there and pulled tank and looking at wiring. Don't know what else to do. Coil seem ok - So where to go from here.
 

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Looks good! My other cheap meter won't even read such a small resistance.

So continuity test the signal wire with the Ohmeter to see if it isn't broken? Brown wire goes to pin 33 at the ECU.
 

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Hopefully I can save you the tracking time?Pins marked on the back of the connector and yes one would have to look in the electrical jack in the box to find the pin numbers.

Pin 33, uppet third one from the front when standing on the L/H side.Strangely enough the spare ECU I bought years ago had corrosion at pin 33.I cleaned that but plating is gone.

28407
 

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Hopefully I can save you the tracking time?Pins marked on the back of the connector and yes one would have to look in the electrical jack in the box to find the pin numbers.

Pin 33, uppet third one from the front when standing on the L/H side.Strangely enough the spare ECU I bought years ago had corrosion at pin 33.I cleaned that but plating is gone.
Pierre, Dan,
See 2 attached photos - something I made for other forum members many years ago.

Pin 33 is ECU ground control from coil 3 pins connector (Pin 1) - to fire cylinder 2-3 pair
Pin 34 is just a normal ground (brown wire)
Pin 35 is ECU ground control from coil 3 pins connector (Pin 3) - to fire cylinder 1-4 pair

NOTE: as documented in upper photo , there is nothing connected to PIN 32

28408


28409
 

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Discussion Starter #156
Thx Both!

Yea, i can't do thigs the easy way and kind of OCD. I had to sit down with manual and open up the equipment box and found the plug was numbered. Then I went through and wrote down number and color of wire for each pin. Took that back to table and created spreadsheet while confirming with MCU/Wiring diagram in Clymers manual.

Can't attach XLS so copied in below.

Note: I did test for continuity from coil side of wire to pins on MCU.

Continuity Test Passed: Just tested again now!!
End of plug for coils 2 - 3 to PIN # 33
End of plug for coils 1 - 2 to PIN # 35

Was hoping that was the problem with non firing of coils 2 - 3. :(

Row NumberingWire ColorsComponents Serviced
Top
19​
Brown/GreenDiagnostic Connector
Top
20​
Yellow/GrayInjector Valve 1 - 4, Diagnostic Connector
Top
21​
Brown (Thick) To Frame Ground
Top
22​
Brown/YellowCoolant Temp Sensor, Air Temp Sensor, Throttle Potentiometer
Top
23​
Red/BlueMotronic Relay, Fuse Box 1 F4 (15A)
Top
24​
BlankN/A
Top
25​
Green/BrownOxygen Sensor
Top
26​
BlankN/A
TopBlank (27)Purple/Black Throttle ActuatorNo Numbering on plug
TopBlank (28)Purple/WhiteThrottle ActuatorNo Numbering on plug
TopBlank (29)Purple/YellowThrottle ActuatorNo Numbering on plug
Top
30​
Black (Skinny)Hall Sensor
Top
31​
OrangeHall Sensor
Top
32​
BlankN/A
Top
33​
Brown (Shielded) Ignition Coil 2 (Feed Cyl No. 2 -3)
Top
34​
Brown (Thick) To Frame Ground, Ties into Coil (Black and Brown) wires
Top
35​
Black Plus BlackIgnition Coil 1 (Feed Cyl No. 1 -4), Tachoneter
Row NumberingWire ColorsComponents Serviced
Bottom
1​
Green/BlackMotronic Relay, Fan Relay, Fuse Box 1 - F1(4A), Fuel Warning Light
Bottom
2​
Brown Hall Sensor
Bottom
3​
Green/YellowThrottle Potentiometer
Bottom
4​
Red (Thin Wire) Hall Sensor
Bottom
5​
White/Red Throttle Potentiometer
Bottom
6​
Brown/Blue Coding Plug
Bottom
7​
PurpleCoolant Temp Sensor
Bottom
8​
Blank N/A
Bottom
9​
White/Black Throttle Potentiometer
BottomBlank (10) Brown/PurpleCoding PlugNo Numbering on plug
BottomBlank (11)Black Oxygen SensorNo Numbering on plug
Bottom
12​
Yellow(Shielded)Oxygen Sensor
Bottom
13​
Brown/Blue Air Temp Sensor
Bottom
14​
Brown/GreenCoding Plug
Bottom
15​
Green/Blue Injector Timing Valve
Bottom
16​
Blue/Purple?Fuel Pump Relay
Bottom
17​
Blue/YellowFan Relay
Bottom
18​
Brown/BlackDiagnostic Connector, Fuel Warning Light Control Unit
 

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Discussion Starter #157
Well-Well

Now were getting somewhere!

For the "H" of it, I tested wiring from HALL Sensor to MCU (PINS 2, 4, 30, 31) - No worries continuity there.

Then I went ahead and removed the MCU and low and behold!!

Socket for PIN #33 shows "Corrosion" - Just like your spare Pierre!

And then I looked at the actual PIN #33 on MCU "Corrosion" Also!!

See attached pictures.

So is the recommendation to clean them up and reinstall MCU and see if that fixes it?

Thx Again folks
 

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Wow.....another one? Got some LPS or Corrosion Block? Either would clean that.And leave enough protection to prevent that happening again.

I like the Corrosion Block made by ACF-50 seeps right in and the little non-aerosol lasted me for years.Just got another one,good for another 10yrs?


I wonder if that corrosion could enter the ECU? I'll go look at what's inside mine, seal is already broken as I had moved my 296 chip in so will be easy to open.
 

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Pin on the ECU goes through the plastic/nylon block by 1/2"+.Looks molded in so corrosion shouldn't enter.
28417


Connector side? I removed a terminal, pretty easy.If required pull the pink lock thing away and push a needle in the little square opening to bend the metal lock tab on the terminal.Pull the terminal.

28418
 

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Pin on the ECU goes through the plastic/nylon block by 1/2"+.Looks molded in so corrosion shouldn't enter.


Connector side? I removed a terminal, pretty easy.If required pull the pink lock thing away and push a needle in the little square opening to bend the metal lock tab on the terminal.Pull the terminal.
..
.....
Pierre,
Thanks for the heads up I have never seen any such corrosion on mine last time I checked (8 years ago) at 100,000 KM.

WHY would it be only on pin 33 AND why we have not seen such corrosion reported on more K1200RS in last 15 years ?

I also keep track of K1200LT forum for last 10 years - many owners there have more than 150,000 miles AND no one has ever reported such problem or symptoms. In fact I know at least 2 with 300,000 miles in south part of USA. Only possible logic would be the much more complex fairing design is stopping water from coming under fuel tank. Basically the electrical junction box where Motronic is attached is same design on K1200LT as our K!200RS.
 
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