bobcopro
Oct 28th, 2006, 7:15 pm
I had the opportunity to listen in on a speaker phone conversation between a tech and the rep from BMW-NA. The guy actually seemed to know what he was talking about. He was a level II tech. God knows how many levels they had!
The abrupt throttle behavior just off of idle (bucking) was caused by the injector mapping of the on-board computer. Versions of the software prior to 7.0 were set to shut down (return to idle level) the injectors whenever the TPS sensor went to zero (throttle fully released.) This is of course what gives you engine braking. The abruptness of this transition of throttle position closed to just barely open (or visa - versa) is what caused the bucking. Version 7.0 of the software was set to shut the injectors down sequentially one at a time during this closing of the throttle and bring them back up one at a time if the throttle was barely opened again, relieving the bucking condition. They had some issues of run on however (bike failing to engine brake properly) on some units. They released 7.0.1 which changes the algorithm for the timing of injector shutdown (made the sequence faster.)
They have a theory that the bikes that are stalling may have any issue with the throttle slides shutting completely instead of going into the position for idle (bike starves of air.) They are trying to figure if this is an issue of the algorithms in the software or of the slides misinterpreting the supply voltage.
Lastly he asked about the high idle conditions. The NA tech asked if the TPS had been reset to see if that clears the problem. Reset requires the battery be disconnected for 10 minutes. After re-connect the key should be turned to the on position (do not start) and the self diagnostics allowed to complete. Then fully open and close the throttle 3 times. Shut the key off, wait for the 70 second time out for all to power down. Then start the bike and test it.
It seems they believe these problems are not directly related which is why some have some problems and not others.
Of course after all this my bike refused to take the update after 9 attempts. My local tech is good and has been doing BMW for 25 years, but he's not computer savvy. I'm waiting to here back on this, but I suspect he should have removed power to the bike at some point and given the computer a chance to reset. It would claim it took the update, then report the previous version. I'm going to pull the batter cable tonight just to see if it will load the update upon reboot. It seems this may be an issue that causes others who have had the 7.0 update to still have bucking problems, if my mechanic had not gone back and rechecked he would not have known the update didn't take. Maybe there's an advantage to having your tech insecure about computer stuff!
I hope this long winded posts help some. I do not guarantee the accuracy of any of this and will not give my mechanics name as evidently BMW doesn't like customers listening in on tech calls. It does sound like they are working on these issues.
The abrupt throttle behavior just off of idle (bucking) was caused by the injector mapping of the on-board computer. Versions of the software prior to 7.0 were set to shut down (return to idle level) the injectors whenever the TPS sensor went to zero (throttle fully released.) This is of course what gives you engine braking. The abruptness of this transition of throttle position closed to just barely open (or visa - versa) is what caused the bucking. Version 7.0 of the software was set to shut the injectors down sequentially one at a time during this closing of the throttle and bring them back up one at a time if the throttle was barely opened again, relieving the bucking condition. They had some issues of run on however (bike failing to engine brake properly) on some units. They released 7.0.1 which changes the algorithm for the timing of injector shutdown (made the sequence faster.)
They have a theory that the bikes that are stalling may have any issue with the throttle slides shutting completely instead of going into the position for idle (bike starves of air.) They are trying to figure if this is an issue of the algorithms in the software or of the slides misinterpreting the supply voltage.
Lastly he asked about the high idle conditions. The NA tech asked if the TPS had been reset to see if that clears the problem. Reset requires the battery be disconnected for 10 minutes. After re-connect the key should be turned to the on position (do not start) and the self diagnostics allowed to complete. Then fully open and close the throttle 3 times. Shut the key off, wait for the 70 second time out for all to power down. Then start the bike and test it.
It seems they believe these problems are not directly related which is why some have some problems and not others.
Of course after all this my bike refused to take the update after 9 attempts. My local tech is good and has been doing BMW for 25 years, but he's not computer savvy. I'm waiting to here back on this, but I suspect he should have removed power to the bike at some point and given the computer a chance to reset. It would claim it took the update, then report the previous version. I'm going to pull the batter cable tonight just to see if it will load the update upon reboot. It seems this may be an issue that causes others who have had the 7.0 update to still have bucking problems, if my mechanic had not gone back and rechecked he would not have known the update didn't take. Maybe there's an advantage to having your tech insecure about computer stuff!
I hope this long winded posts help some. I do not guarantee the accuracy of any of this and will not give my mechanics name as evidently BMW doesn't like customers listening in on tech calls. It does sound like they are working on these issues.