Problem with O2 Sensor 2007 R1200R

[botus]

find another bike and see how theirs behaves.....

 

[Roger 04 RT]

Spent hours today trying to solve this problem. Bought some new bmw female pins yesterday. Swapped out #90. Circuit belled out perfectly. Resistance of 0.02 ohms.
Same problem. Added.a new wire all the way back from pin 90 to the black wire on the O2 sensor. Same problem again. Cylinder 1 output trace constant at 0.45 v.

Rechecked the grey wire up to pin 43 on BMSK connector. 0.02 ohms also. Perfect.

Tried everything again. Same issue.

Re-made the pin connection at pin 90. Same problem.


Swapped O2 sensors- all 3 showed the same.

Am of the opinion that the open circuit the bmsk module is seeing is within the BMSK module itself.

Perhaps a dry solder joint within the module.

Anyway, it is certainly nothing to do with the wiring loom or O2 sensors.

A royal pain in the ass. 5 hours of highs / lows / swearing / ideas and disappointments.

Ah well, the bike rides great, loads of power and 50 mpg. May as well have to live with it

Any other ideas while I drown my sorrows in Guinness ?

Thanks all.

Fergus, I wouldn't live with the probem.

There is an O2+ and O2- lead and an open in either will cause your problem. If you're positive both wires are good up to the connector pins, your problem is in the BMSK. Also have you checked that you have continuity through the 4-pin connector that the O2 uses. Sometimes one of those pins pushes loose.

If you're careful you can open the BMSK and check the traces on the PCB from the two O2 pins to the first IC.

Another idea would be to disconnect the O2, start the bike, and measure the voltage at the harness on pins 3 & 4. Without the O2 connected you should measure around 450 mV.

 

[ferguscawley]

Fergus, I wouldn't live with the probem.

There is an O2+ and O2- lead and an open in either will cause your problem. If you're positive both wires are good up to the connector pins, your problem is in the BMSK. Also have you checked that you have continuity through the 4-pin connector that the O2 uses. Sometimes one of those pins pushes loose.

If you're careful you can open the BMSK and check the traces on the PCB from the two O2 pins to the first IC.

Another idea would be to disconnect the O2, start the bike, and measure the voltage at the harness on pins 3 & 4. Without the O2 connected you should measure around 450 mV.

Roger

Thanks for your reply. The connector at the O2 sensor is missing so this has been replaced with soldered joints.

I will disconnect the O2 sensor and measure voltage as you suggest in the next day or so and let you know what I observe.

If nothing there I'll open up the BMSK and try to trouble shoot that way.

Thanks again

Fergus

 

[botus]

repair plugs.... (not sure the one you need are listed...)

https://www.realoem.com/bmw/en/show...25-BMW-R_1200_GS_04_0307,0317_&diagId=61_2484

https://www.realoem.com/bmw/en/show...25-BMW-R_1200_GS_04_0307,0317_&diagId=61_2485

 

[Roger 04 RT]

Roger

Thanks for your reply. The connector at the O2 sensor is missing so this has been replaced with soldered joints.

I will disconnect the O2 sensor and measure voltage as you suggest in the next day or so and let you know what I observe.

If nothing there I'll open up the BMSK and try to trouble shoot that way.

Thanks again

Fergus

It’s not causing your “open circuit” problem but the O2 sensor gets its reference air through the space between wires. Because of that the wires should not be soldered which possibly starves it of outside air.

 

[ferguscawley]

It’s not causing your “open circuit” problem but the O2 sensor gets its reference air through the space between wires. Because of that the wires should not be soldered which possibly starves it of outside air.

Am not sure what you mean by that ?

The connector I'm talking about is the male 4 pin black connector that comes attached to the O2 sensor. Just an electrical connector. The corresponding female connector forms part of the bike's loom. This too is missing, so the O2 sensor is connected via 4 individually insulated soldered joints instead.

Fergus

 

[Mistacat]

I think what Roger is referring to is that the 02 sensor gets its reference air from between the wires , that is inside the outer insulation sleeve from the 02 sensor.
If you solder the wires it would be easy to tape up the outer insulation covering the four wires where the plug was, hence cutting off the reference air supply to the O2 sensor.

 

[Santa-2512]

I think what Roger is referring to is that the 02 sensor gets its reference air from between the wires , that is inside the outer insulation sleeve from the 02 sensor.
If you solder the wires it would be easy to tape up the outer insulation covering the four wires where the plug was, hence cutting off the reference air supply to the O2 sensor.

Thats interesting, my understanding was that the O2 sensor measured the amount of air in the exhaust gases and used

either a pre programmed set of reference values in the ECU or used the MAF &/or MAP data as reference values, and this data combined gave the lambda value

 

[ferguscawley]

I think what Roger is referring to is that the 02 sensor gets its reference air from between the wires , that is inside the outer insulation sleeve from the 02 sensor.
If you solder the wires it would be easy to tape up the outer insulation covering the four wires where the plug was, hence cutting off the reference air supply to the O2 sensor.

But the 4 wires leaving the head of the O2 sensor are just that - wires . Not sensors. They can't detect anything surely ?

The sensor itself is in the exh gas flow sealed from external air via a sealing washer.

Maybe I'm missing something here ?

 

[Santa-2512]

But the 4 wires leaving the head of the O2 sensor are just that - wires . Not sensors. They can't detect anything surely ?

The sensor itself is in the exh gas flow sealed from external air via a sealing washer.

Maybe I'm missing something here ?

Yes and no

It would appear there are many types of O2 sensor,

some use data from the MAP & MAF to get a reference value for the air going into the system,

others use sample of ambient air drawn from the sensor itself (drawn from the air thats in the "void" in one of the electrical wires )

Some have holes in the base of the O2 housing to draw reference air in

The one's that sample air at point of operation, all suffer from one small inherent problem,

water or other contaminants can get drawn into the sensor and block it, thus preventing it from getting a reference value.

on a car, not a big issue as if your O2 sensor deep in water - youve got bigger issues to worry about..

But on a bike, theoretically it could give an issue if you like going through puddles

 

[ferguscawley]

Thanks for that lesson in O2 sensors. Much appreciated

 

[ferguscawley]

There are 4 small holes spaced equally around the external part of the sensor. Maybe that is where the reference air comes from ?

 

[ferguscawley]

Did as Roger suggested.

Disconnected the black and grey wires from the O2 sensor and connected my multimeter to the connector block to measure the bmsk output voltage.

At the start, ignition on, bike not yet started I saw 0.45V.

When I started it, the voltage fluctuated a little (went up to about 0.7 V) and then essentially decayed to zero.

See video below.

Subsequent tests gave no voltage with ignition on, engine not running, nor with engine running.

It's strange. There seems to be the correct voltage present at the (first) start and then it decays to zero.

Photo is of connection to loom.

https://www.youtube.com/watch?v=uYhQa1-ZYZ8

 

[Santa-2512]

2 wires are the heater circuit & 2 the Lambda sensor itself

The heater is to get the tip of the sensor up to around 600c (where its at its best to work)

you may be measuring the heater circuit?, once the sensor tip is warm, it does not need any help from the heater circuit

the voltage from the sensor has a very small range,

If i recall 0.97v to 1.3v

i would repeat your testing with all 3 sensors on both sides then compare results

 

[ferguscawley]

Santa

Am not measuring the heater circuit - they are the 2 white wires. I am measuring the voltage on the wires from the BMSK to the sensor (black & white) wires.

I'll swap another sensor in and try that again as well for comparison sakes

 

[Santa-2512]

Santa

Am not measuring the heater circuit - they are the 2 white wires. I am measuring the voltage on the wires from the BMSK to the sensor (black & white) wires.

I'll swap another sensor in and try that again as well for comparison sakes

no probs -

If you measure all sensors all 4 wires on each side, you should have a block of data that should point to where the issue lies

So you'll end up with 12 readings for the LH side & 12 readings for the right

once you have them, post them up - it may give us a bit more idea

 

[Roger 04 RT]

Did as Roger suggested.

Disconnected the black and grey wires from the O2 sensor and connected my multimeter to the connector block to measure the bmsk output voltage.

At the start, ignition on, bike not yet started I saw 0.45V.

When I started it, the voltage fluctuated a little (went up to about 0.7 V) and then essentially decayed to zero.

See video below.

Subsequent tests gave no voltage with ignition on, engine not running, nor with engine running.



It's strange. There seems to be the correct voltage present at the (first) start and then it decays to zero.

Photo is of connection to loom.

https://www.youtube.com/watch?v=uYhQa1-ZYZ8

Fergus—That’s surprising—you did have the black and grey wires disconnected, right? (Just saw the picture, looks good). I expected 450 mV stable (could be 500, but in that range). Can you run the same test on the good side?

Disconnect that O2 and measure the BMSK (bike) side of the connection.

 

[Roger 04 RT]

There are 4 small holes spaced equally around the external part of the sensor. Maybe that is where the reference air comes from ?

They might or might not be holes for reference air, I don’t know. As Santa2512 said, on the 1200 they are in an area where those holes could be compromised with rain and debris.

 

[Roger 04 RT]

2 wires are the heater circuit & 2 the Lambda sensor itself

The heater is to get the tip of the sensor up to around 600c (where its at its best to work)

you may be measuring the heater circuit?, once the sensor tip is warm, it does not need any help from the heater circuit

the voltage from the sensor has a very small range,

If i recall 0.97v to 1.3v

i would repeat your testing with all 3 sensors on both sides then compare results

Good explanation except the heater does come on periodically while riding depending on engine load. The O2 sensor range is 0-1V. Normally between 200-850 mV.

 

[ferguscawley]

Fergus—That’s surprising—you did have the black and grey wires disconnected, right? (Just saw the picture, looks good). I expected 450 mV stable (could be 500, but in that range). Can you run the same test on the good side?

Disconnect that O2 and measure the BMSK (bike) side of the connection.

Hi Roger

yep - sensor was disconnected so I was just measuring the voltage on the BMSK (bike side)

I will try the other (good) side and see what I get