Evening Folks...
Hope this is the place to post these questions...
Started a thread on the general forum and still having some issues.
I spent all day today cleaning and checking things out on the bike.
Under the tank and wiring is now factory clean...all connectors have been unplugged...cleaned and treated with contact grease...including the EFI and ABS computer plugs.
Bike runs perfectly when cold...but after about 30 min of highway riding and you come to a stop light...you can hear an intermittent miss at idle...when you try to take off...it just falls flat and runs on two cyl...at about 1500/2000 rpm...all four light up and it runs perfectly. seems to break down under load until it makes a few RPM. It has new wires and plugs. I swapped the coils around and it seems the miss still stays on 2/3...this was done on the stand and a bit hard to tell without a load on the bike. On the road...runs like a freight train. Suggestions??? Thought I'd start with replacing the Hall effect sensors. I may have some old coils that would work for testing too.

My ABS light is still blinking...been through the reset procedure and still flashing.
Would love to find a method to read the error codes as there's not a dealer anywhere near.
I'm sure there are Ohm reading for the wheel sensors etc...be a place to start at least.
Should be a method of testing the pump motors as well... Any ABS Gurus our there????
Thanks,
ED

ABS I Diagnostic Methods

By Brian Curry
September 1998

Generally when the ABS lights start flashing, people start seeing dollar signs since there seems to be very little info on it out there, and what is there, has you testing using the BIG DOLLAR $$$ BMW test tool.

This is some info on how to find out what is causing the fault using a Volt Ohm Meter (VOM) and then how to investigate and narrow it down more using that same VOM. This is written based on ABS I. ABS II is similar, but has different codes.

The fault code is indicated at the diagnostic connector that the BMW tool connects to. On my K75 the diagnostic connector is located on the bike right side under the side panel. It plugs into a blue "blank" connector tiewrapped to the frame. There are three pins on this connector. I was not able to detect any voltage on the outer, number 1 and 3 pins.

The center, number 2, pin is where the fault codes are indicated. This pin has about 0.5 to 0.75 volts on it with the bike shut off. When the ignition is turned on, the voltage rises to about 10 volts. When all is well, it stays at 10 volts. However, if there is a fault, it drops towards zero (pulses) in a periodic manner. When there is a fault, every so often, the voltage pulses downwards toward 0 volts. The number of pulses, indicates the fault number. In other words, if it pulses downwards 4 times, that indicates that there is a problem with the fault code number 4 items. The pulsing also occurs when the ignition is first turned on and the voltage is rising to ~10 volts, but it is easier to spot when it occurs periodically later. I was able to see the pulses easily using an analog meter. It can also be seen using a digital meter. There is not enough current available to light a light. I tried.

With the fault code number, troubleshooting can proceed.

First the ABS plug is numbered as shown below. Yes, it is a PITA to get the ABS brain out and the plug disconnected from the ABS I but some tests have to be done from there. With the pin sockets toward you, and the cable on the right, it is numbered from the right to the left, bottom and then top. This is important.

25 14

____________________________________

| \_______

| _______ Cable

|____________________________________/



13 1

System voltage test. Power is supplied on Pin 15, and Pin 14 is ground. Connect to them, and confirm that when the ignition is turned on, the voltage is the same as at the battery.

Fault Code 1 - Front Pressure Modulator
ABS connector pins of interest	6,9,10
Test Value	resistance
Resistance 6-9	~4.48 k-ohms
Resistance 6-10	~16.7 K-ohms
Resistance 9-10	~19.5 K-ohms

If an open is indicated, check the wires from the brain plug to the Modulator plug. If those connections are OK, the modulator is bad.

Remove the ABS relay in the electrical box under the tank. The relay is at the front of the box, on the left side, just beside where the front wiring harness enters the box. Measure resistance from the ABS relay socket to ground. Measure from 87 to frame ground. It should measure 17.4 K-ohms.

Socket:

30

_________

| __ |

| |

87 | | __ | 86

| | __ |

|_________|

85

Again, if it is open circuit check from the socket to the Modulator plug. Then check from Terminal 31 of the Modulator to ground. Again, if the wiring is good, the modulator is bad.

With the ignition off, the ABS relay socket connection Pin 30 should be the same as the battery voltage. If not, check that connection point is secure, and the red wire from the battery to connection point 30.

Fault Code 2 - Rear Pressure Modulator
ABS connector pins of interest	7,11,12
Test Value	resistance
Resistance 7-11	~4.48 K-ohms
Resistance 7-12	~16.7 K-ohms
Resistance 11-12	~19.5 K-ohms

If an open is indicated, check the wires from the brain plug to the Modulator plug. If those connections are OK, the modulator is bad.

Remove the ABS relay in the electrical box under the tank. The relay is at the front of the box, on the left side, just beside where the front wiring harness enters the box. Measure resistance from the ABS relay socket to ground. Measure from 87 to frame ground. It should measure 17.4 K-ohms.

Again, if it is open check from the socket to the Modulator plug. Then check from Terminal 31 of the Modulator to ground. Again, if the wiring is good, the modulator is bad.

With the ignition off, the ABS relay socket connection Pin 30 should be the same as the battery voltage. If not, check that connection point is secure, and the red wire from the battery to connection point 30.

Fault Code 3 - Front Wheel Speed Sensor
ABS connector pins of interest	1,2
Test Value	resistance
Resistance 1-2	~135 +/-20 ohms

If the reading is an open circuit, measure resistance from ABS connector pins 1 and 2 to the frame ground. It should be an open circuit. If it is not, check the wiring to the speed sensor. If the wiring is OK, the sensor is shorted internally and it will need to be replaced.

If resistance reading is not correct, check wiring from pins 1 and 2 to the front wheel speed sensor, and the plug connection at the front wheel speed sensor. If the wiring is good, the speed sensor is bad and needs replacement.

If the resistance reading is correct, replace the ABS brain.

Fault Code 4 - Rear Wheel Speed Sensor
ABS connector pins of interest	3,4
Test Value	resistance
Resistance 3-4	~135 +/-20 ohms

If the reading is an open circuit, measure resistance from ABS connector pins 3 and 4 to the frame ground. It should be an open circuit. If it is not, check the wiring to the speed sensor, if the wiring is OK, the sensor is shorted internally and it will need to be replaced.

If the resistance reading is not correct, check wiring from pins 3 and 4 to the rear wheel speed sensor, and the plug connection at the rear wheel speed sensor. If the wiring is good, the speed sensor is bad, and needs replacement.

If the resistance reading is correct, replace the ABS brain.




Fault Code 5 - Battery Voltage Too Low

Power (~12.6V) is supplied on Pin 15, and Pin 14 is ground. Connect to them, and confirm that when the ignition is turned on, the voltage is the same as at the battery.

If not: Check the battery charge and condition (Load test.) Check the pin 14 to frame ground connection. Check the battery, frame, and engine ground connections. Check ABS connector pin 15 to ignition switch terminal 15. Check wiring from the battery positive connector to the ignition switch.

If all the wiring is OK, replace the ABS brain.

Fault Code 6 - ABS relay
ABS connector pins of interest	17,19
Test Value	resistance
Resistance 17-19	<92 OHMS (LESS THAN 92 OHMS)

If an open circuit is indicated check ABS connector pin 17 to the ABS relay socket terminal connection 86, and check ABS connector pin 19 to the ABS relay socket terminal connection 85. If the wiring is good, then check the relay.

If the resistance is off, measure between relay terminals 85 and 86. If it is not less than 92 ohms, replace the relay.

Fault Code 7 - ABS Control Unit
ABS connector pins of interest	1,3,17
Test Value	resistance
Resistance	Open circuit to ground.

Measure between each of the pins and ground, it should indicate an open circuit. Pin 1 is the front wheel speed circuit and should be open to the speed sensor shell. Pin 3 is the rear wheel speed circuit and should be open to the speed sensor shell. Pin 17 is the ABS relay socket terminal 86 and should be a open circuit from it to ground. Also, from Pin 17 to ABS relay socket terminal 86, it should be a closed circuit.

If these indicate correct, the ABS brain is bad.

(In at least one instance the ABS faulted, indicating the ABS brain, but it would reset, and worked fine afterward. So, there might be some conditions that are intermittent and self curing. If so, knowing how to reset the brain and see if it has cured itself, may have saved you a BUNCH OF MONEY.)




Fault Code 8 - Outside influence
Speed sensor gap

This fault can be caused by low battery voltage, loose wheel speed sensor, or incorrect speed sensor gap.

The battery voltage has already been tested by now, testing sequentially. Grab them, and check that the sensors are secure. Check the speed sensor gaps. My front wheel sticker says 0.35-0.65 mm. However the Service manual and the owner's manual say that it should be 0.60-0.65 mm front, and rear. It is to be measured where the chisel punch point is on the speed sensor (toothed gear).

ABS Warning indicator is continuously on
ABS connector pins of interest	18,19
Test Value	resistance
Resistance 18-19	110 +/-20 ohms

If it is not correct, check from ABS connector pin 18 to the ABS warning relay terminal 86 and, check from ABS connector pin 19 to the ABS warning relay terminal 85. (The warning relay is in the electrical box, front right, just to the right of the wiring harness entry. The relay terminal orientation and numbering are different from the ABS relay.)

Socket:

___________

| ___ |30

| ___ |87a

| |

| | | |

86 | | | |85

|___________|

The wiring should have virtually no resistance to the socket. The relay coil resistance between pins 86 and 85 should be 110 +/-20 ohms.

ABS connector pin of interest	5
Test Value	resistance
Resistance	Open circuit to ground.

Measure from ABS connector pin 5 to frame ground.

If it is an open circuit replace the brain. If an open circuit is not indicated, check pin 5 to the ABS switch. If wiring is good, replace the ABS switch.




I would like to thank Steve Burkholtz who in a message back on 16 Oct 1997 noticed that the center pin voltage varied. Using a VOM to determine the fault codes takes some skill, but is WAY CHEAPER than using the BMW tool, which I think is about US$1500!

Also to be thanked is Richard Paton <RICHARD@DYNAMO.COM.AU> who on 15 Oct 1997 gave instructions for resetting the ABS.

Thanks to Rob Scott who confirmed that you can see the pulsing with a digital voltmeter. (And who saved himself a trip to the dealer to find out what was wrong, and reset the ABS computer.)

http://www.ibmwr.org/ktech.shtml Most answers are here.

hcritz
Keep it simple matey.
First clean your wheel teeth of the ABS with emery as the sensor cannot read it if full of crap. Probably just a maintenance problem.
Brian Curry's article is a great help, [thanks Brian]
You will find most problems are just simple to rectify.
Ajays.

If the same cylinders cut out after changing the coils around I would indeed look at the Hall sensors as they trigger the signal for the coils. Another thing could be the injection module which has been reported to aquire moisture.

Hey Ajays....
Thanks for the info...that will help a LOT...
Have you ever tried using an LED to watch the pulses??? May give that a try.
I think I still have an old analog VOM stached away in a cabinet somewhere...have to see if I can find it and if it still works.
I'll report back when I have time to sit down and go through all the test.
The ABS rings are clean...I will also take the sensors out and make sure they haven't built up any metal particals...seen that on autos with ferous material in the brake pads.
At this point I'm tempted to just remove the ABS relay and Light relay until I have more time! LOL
Thanks!!!
Ed

Hey Renez.
Going to try some old 3 ohm coils I have at the shop...make sure it's not a coil...then on to the Hall effect sensors.

Hi There,
Have you measured the battery voltage with a reasonably accurate meter at idle? The alternator does not charge at idle so the battery is discharging and if the voltage from the battery is lowish that will trigger the ABS into fault.

My suggestion is start simple, check battery voltage with the engine off, press the start button whilst monitoring battery voltage as you do that and then the battery voltage when it is idling.
Regards,
K-BIKE

Well...the mystery miss is solved, it ended up being the 2/3 coil. I put on a 3 ohm honda coil and all is good with the world. Dead steady idle and no stumble at start off. I may just get a couple of the Dyna 3 ohm ones and fabricate a bracket for them. It was very strange behavior for a coil to break down with those symptoms.
I'll tackle the ABS next week.
I did get the final drive for my R60/5 back together with new seals and gaskets.
Got the rim polished...respoked with stainless spokes...trued...the new tire installed...the swing arm off and stripped of grease and old paint. Busy Day! Been waiting on spokes to arrive...been missing my old R...it's my daily urban assault bike.

But how is that posible when youi have changed the coils and still the same cylinders were cutting out??

Happy you found the culprit, but it doesn't add up to me.

Hey Rene...
It was hard to determine which cyl. was dropping on the center stand with no load...I swapped the coils aound and it appeard that the miss didn't move. I was using a inductance timing light to watch the spark pattern....it was getting some weird patterns on the 2/3 circuit. Appears that it was just the coil though.
Swapped in the honda coil and it runs great.

Glad to see it is all up and running and the really useful part which I don't think I have come across anywhere is the option of a shock horror non genuine coil.

There is a lot of examples of the old coils with cracks so it is even possible you have two faulty coils which would make fault finding a tad difficult.

Sounds like we need a picture of the 60/5 when back together just for a bit of nostalgia.

Hello Phil...
I have been thinking the same thing...that maybe both coils are going bad. The 1/4 may be weak as well. The Honda coils generate a much hotter spark. I think I'll be safe and replace both.
I'll post some picts of the R here soon...hope to have it back on the road this week.

Well...got the ABS light off...not sure why though??? went through the ohm testing and did another reset and the light is off...I won't question success. By the way...an LED works well for reading the error codes...I had a 12V one and it wasn't real bright but def visible. I suspect on of the lower voltage ones would work nicely.
I was getting a code 7...of course...the worst...replace the brain one. I did take the brain box out and open it up...checked for bad solder joints etc...all looked OK.
I talked with Dynatec...and they have two coils that should work with these bikes...their Std Green 3 ohm and a newer more compact 3 ohm.
Thanks for the help!!!
Ed