kmurphy165
Sep 25th, 2006, 6:15 pm
Hi, Folks. Ok, here goes part 2 of my trouble with the anti lock brake sensor cable.
As a reminder, two days after getting back from CCR without any troubles with the LT at all, I pulled out of the garage to see that the brake system completes the self test, but does not complete the pull a way test. Applying the brakes results in the general warning light coming on and the brake / anti lock warning light flashing at the slow, 1 hz cycle. According to the chart in the owners guide book, that means that at least 1 anti lock circuit is not working. Driving out to Beemers and More, I saw the speedometer flip flop and quit working. I immediately surmised that the fault was in the rear wheel speed sensor cable breaking. When next I looked down, the speedometer was working again. !!!!!!! :confused:
So, I removed the sensor, checked for chafing in the outer cable, removed sections of the outer cable to check for chafing of the inner wires. I rigorously checked the continuity of each wire, end to end and across the sensor. With help, I checked the continuity of both wire/circuit scenarios within the cable while the entire cable was repeated flexed to see if there was an intermittent break. No such break was detected, not was a broken wire ever detected. So, after learning that yes, shrink wrap can be over heated, I repaired the cable insulation and reinstalled the sensor and cable on the bike.
And of course, it doesn't work! :eek: The pull a way test doesn't complete and the speedometer isn't working.
Now, please note the following observations:
1) across the two prongs inside the sensor cable plug, I see 25.60 m ohms resistance. If the one or both wires inside of the cable was broken, then there would be infinite ohms. If one wire inside of the cable was shorted to the other, I would see a shorted continuity, i.e. little or no ohms resistance.
2) while slowly rotating the rear wheel with the sensor installed, I see no change in resistance of the sensor/cable. It seems to me that I read on the archived posts a comment from Mr. Shealy that there should be a change in resistance shown by the sensor as the segments on the wheel ring pass in front of the sensor.
3) the rear wheel brake reservoir has been carefully filled to exactly the max mark. This with the bike on the center stand in the garage on the level garage floor. I see no level marks relative to the rear fill cap on the rear wheel brake circuit reservoir. It appears that the brake fluid level is consistent all across the reservoir, front to back.
4)During the test ride, the brake warning light indicated that the system self test is completed and the pull a way test does not complete.
5) Both front and rear wheel sensors have been cleaned of all debris and the rear wheel sensor has been tested with both all three original spacers in place and with only two spacers. No difference in result.
6) I disconnected the negative terminal of the battery for close to an hour to allow the onboard controllers to reset to default condition and to clear any codes. I carefully followed the switch on, open throttle fully twice before starting and test riding.\
7) The brake servo boosters are working.
8) the battery tender is plugged in at all times the bike is parked in the garage.
9) the sensor cable connector plug is firmly inserted in the harness connector and the retainer clip is double checked to be engaged.
I'm inclined to suspect that the sensor on the rear wheel has failed and is not sensing the segments on the wheel ring passing in front of it. Or, the anti lock controller has failed. I truly wish that our community's experts would throw in on this as I'm at a lost and the local BMW dealer wants $90 to hoot the bike's moronic box to their diagnostic guesser to read any codes. If I have to resort to either the official dealership, or my shop, the problem will not be fixed for many months and the bike won't be ridden because I cannot afford to spend several hundred dollars on repairs.
Well, that's all I can recall to report on this problem. I want to express my appreciation to all who offered ideas and support when I first brought this problem to the community the first time.
Thanks again in advance for all advice and help.
Puzzled Karl
As a reminder, two days after getting back from CCR without any troubles with the LT at all, I pulled out of the garage to see that the brake system completes the self test, but does not complete the pull a way test. Applying the brakes results in the general warning light coming on and the brake / anti lock warning light flashing at the slow, 1 hz cycle. According to the chart in the owners guide book, that means that at least 1 anti lock circuit is not working. Driving out to Beemers and More, I saw the speedometer flip flop and quit working. I immediately surmised that the fault was in the rear wheel speed sensor cable breaking. When next I looked down, the speedometer was working again. !!!!!!! :confused:
So, I removed the sensor, checked for chafing in the outer cable, removed sections of the outer cable to check for chafing of the inner wires. I rigorously checked the continuity of each wire, end to end and across the sensor. With help, I checked the continuity of both wire/circuit scenarios within the cable while the entire cable was repeated flexed to see if there was an intermittent break. No such break was detected, not was a broken wire ever detected. So, after learning that yes, shrink wrap can be over heated, I repaired the cable insulation and reinstalled the sensor and cable on the bike.
And of course, it doesn't work! :eek: The pull a way test doesn't complete and the speedometer isn't working.
Now, please note the following observations:
1) across the two prongs inside the sensor cable plug, I see 25.60 m ohms resistance. If the one or both wires inside of the cable was broken, then there would be infinite ohms. If one wire inside of the cable was shorted to the other, I would see a shorted continuity, i.e. little or no ohms resistance.
2) while slowly rotating the rear wheel with the sensor installed, I see no change in resistance of the sensor/cable. It seems to me that I read on the archived posts a comment from Mr. Shealy that there should be a change in resistance shown by the sensor as the segments on the wheel ring pass in front of the sensor.
3) the rear wheel brake reservoir has been carefully filled to exactly the max mark. This with the bike on the center stand in the garage on the level garage floor. I see no level marks relative to the rear fill cap on the rear wheel brake circuit reservoir. It appears that the brake fluid level is consistent all across the reservoir, front to back.
4)During the test ride, the brake warning light indicated that the system self test is completed and the pull a way test does not complete.
5) Both front and rear wheel sensors have been cleaned of all debris and the rear wheel sensor has been tested with both all three original spacers in place and with only two spacers. No difference in result.
6) I disconnected the negative terminal of the battery for close to an hour to allow the onboard controllers to reset to default condition and to clear any codes. I carefully followed the switch on, open throttle fully twice before starting and test riding.\
7) The brake servo boosters are working.
8) the battery tender is plugged in at all times the bike is parked in the garage.
9) the sensor cable connector plug is firmly inserted in the harness connector and the retainer clip is double checked to be engaged.
I'm inclined to suspect that the sensor on the rear wheel has failed and is not sensing the segments on the wheel ring passing in front of it. Or, the anti lock controller has failed. I truly wish that our community's experts would throw in on this as I'm at a lost and the local BMW dealer wants $90 to hoot the bike's moronic box to their diagnostic guesser to read any codes. If I have to resort to either the official dealership, or my shop, the problem will not be fixed for many months and the bike won't be ridden because I cannot afford to spend several hundred dollars on repairs.
Well, that's all I can recall to report on this problem. I want to express my appreciation to all who offered ideas and support when I first brought this problem to the community the first time.
Thanks again in advance for all advice and help.
Puzzled Karl