• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

  • Beginning April 1st, and running through April 30th, there is a new 2024 BMW MOA Election discussion area within The Club section of the forum. Within this forum area is also a sticky post that provides the ground rules for participating in the Election forum area. Also, the candidates statements are provided. Please read before joining the conversation, because the rules are very specific to maintain civility.

    The Election forum is here: Election Forum

Need help from the masters

heavyjetpfe

heavyjetpfe

New member
About a month ago I rode through the worst rain storm I've ever encountered. The morning after the storm I went to start my 06 12RT. The BMW CB wouldn't transmit, The BMW Motorad II GPS wouldn't give correct directions and the LED display for the engine computer looked like a Christmas tree. After leaving it in the sun and wind for a few hours the CB and engine computer seemed to straighten them selfs out. Now I have an intermintant shut down (extreme loss of power). This can happen at any speed or RPM. I've changed the air filter, fuel filter coils, plugs and O2 sensors. The BMW service department agrees there is a problem but the computer is not providing any codes. The mechanics at my dealer say they have never seen this before and the problem has been handed over to the engineers in Germany. Would any of the master techs. on this forum care to chime in. Thanks Ron
 
This may sound overly simplistic, but make sure your cables to your battery are good and tight, as well as clean. This, similar anyhow, is not that uncommon.

Jim :brow
 
Battery cables are clean and tight. Today the regional Rep told the service department to change the fuel pump. That should be installed tomorrow. I'll keep you all posted on the results
 
Fuel pump?

heavyjetpfe said:
Battery cables are clean and tight. Today the regional Rep told the service department to change the fuel pump. That should be installed tomorrow. I'll keep you all posted on the results
Click to expand...

Reminds me of the time my company car was not shifting properly and obviously needed a linkage adjustment . . the dealer "service advisor" asked me what octane fuel I was using.
 
The simple answer is very simple - connections or exposed wiring got wet. Some has dried out - some has not dried completely.

The trick is to find out what wiring is still wet. If I wanted to be perfectly methodical I would identify (from the book) every component which if bad generates a fault code. Then I would look elsewhere. First; when it dies is it losing fuel, ignition, or both.

If both, suspect the Hall Sensor wiring or the main ECU connector.

If one or the other - then proceed along the injector circuits or the coil circuits.

Or, take off all the plastic and the fuel tank, set it in the Sun, and blow a huge fan on it for a few hours.
 
PGlaves said:
The simple answer is very simple - connections or exposed wiring got wet. Some has dried out - some has not dried completely.

The trick is to find out what wiring is still wet. If I wanted to be perfectly methodical I would identify (from the book) every component which if bad generates a fault code. Then I would look elsewhere. First; when it dies is it losing fuel, ignition, or both.

If both, suspect the Hall Sensor wiring or the main ECU connector.
Click to expand...
Paul, there is no HES on hexheads - they use camshaft postion sensors instead..
If one or the other - then proceed along the injector circuits or the coil circuits.

Or, take off all the plastic and the fuel tank, set it in the Sun, and blow a huge fan on it for a few hours.
Click to expand...
I'd agree on cleaning all the connectors - I'd be R&R each one and making sure it's dry..
 
When it's not acting up get a spray bottle with water in it and start squirting 1 thing at a time until the symptoms appear. Then you'll know where to look. I've used this to fix a lot of cars over the years.
 
deilenberger said:
Paul, there is no HES on hexheads - they use camshaft postion sensors instead..I'd agree on cleaning all the connectors - I'd be R&R each one and making sure it's dry..
Click to expand...

Don,

What type sensors are they. Probably not mechanical switches so I'd vote for Hall Effect Sensors - 2 or 4 instead of 2. Probably sequential fuel squirt too.

My Ford Exploder has both a crankshaft sensor and a camshaft sensor. Or maybe more than one of each. Expensive little puppies too.

But I didn't know the Hexheads didn't have a crankshaft position sensor. But then again - I've never had to mess with one except to tighten the rear mudguard on one while we were touring in Africa. :)
 
PGlaves said:
Don,

What type sensors are they. Probably not mechanical switches so I'd vote for Hall Effect Sensors - 2 or 4 instead of 2. Probably sequential fuel squirt too.

My Ford Exploder has both a crankshaft sensor and a camshaft sensor. Or maybe more than one of each. Expensive little puppies too.

But I didn't know the Hexheads didn't have a crankshaft position sensor. But then again - I've never had to mess with one except to tighten the rear mudguard on one while we were touring in Africa. :)
Click to expand...

The Hexheads also have both. Crankshaft and camshaft sensors, allowing for fully sequential triggering of injection and ignition. They are analog inductive sensors (BMW's words), not HES, which identify the speed and reference of the crankshaft and the position of the camshaft. In addition, both cylinders have knock sensors and cyl head temperature sensors. All that and oil temperature, intake air temperature, and barometric pressure are fed into the BMSK.
In other words, you can burn poor gas from anywhere.
 
PGlaves said:
Don,

What type sensors are they. Probably not mechanical switches so I'd vote for Hall Effect Sensors - 2 or 4 instead of 2. Probably sequential fuel squirt too.
Click to expand...
Simple magnetic inductance ones - lot like the ABS sensor. They've been using the same ones on the cars for several decades.
My Ford Exploder has both a crankshaft sensor and a camshaft sensor. Or maybe more than one of each. Expensive little puppies too.

But I didn't know the Hexheads didn't have a crankshaft position sensor. But then again - I've never had to mess with one except to tighten the rear mudguard on one while we were touring in Africa. :)
Click to expand...
Yup - much more up to date on engine control than the oilhead was.
 
deilenberger said:
Simple magnetic inductance ones - lot like the ABS sensor. They've been using the same ones on the cars for several decades.
Click to expand...
I think the first one on the bikes was the speedo pickup on the K100/75. Simple and easier to test, etc. Pretty much ok with heat as well.
 
Don and Jack,

We know what happens when the HES wire bundle (with cracked insulation) gets wet in an Oilhead. Spurious signals and a confused ECU.

What happens (would happen) with a wet wire/bundle/connector from a Hexhead sensor? Do we know? Would it still confuse the ECU? Generate a code?
 
PGlaves said:
Don and Jack,

We know what happens when the HES wire bundle (with cracked insulation) gets wet in an Oilhead. Spurious signals and a confused ECU.

What happens (would happen) with a wet wire/bundle/connector from a Hexhead sensor? Do we know? Would it still confuse the ECU? Generate a code?
Click to expand...
Paul,

I'm hoping we never find out.. So far the bikes haven't had cracked insulation that I've heard of (this could be the first..) so no one has any experience with it. The wires that go to these sensors are located in areas that don't see the heat that the HES sensors/wiring were exposed to on the oilheads and the K bike engines. Hopefully that makes a difference, and hopefully BMW used wire with better thermal properties then was used on the HES sensors.

There have been some very isolated reports of too-tight-tie-wraps - but it's been quite sporadic and mostly limited (from what I've observed/heard) to tie wraps going to normally flexed sections of wiring (like to the steering head..)
 
I don't know what is the output impedance of the new sensors. Thinking about maybe a salty wet soaking, etc, which would parallel the impedance of the sensor and reduce it's output. The impedance of the speedo pickup was about 2.5 K ohms and although the wiring was in the open to some extent, at least one connector was, I don't recall any issues with it. In general, a distance of a quarter inch in a glass of water with a lot of ions in it would result in an impedance of about 10K ohms. I don't think that would short out the sensor significantly.
True that some of the tie wraps on the rear swing arm were so tight that they cut the wire in two inside the insulation. When you read the spec sheets on the HE sensors, they have a pretty low temperature limit. I remember thinking that I wouldn't have used them where they were used by BMW. The inductive pickups are more bullet proof in that regard.
 
still an expensive paper weight

I spoke with the service department today. They installed the new fuel pump as instructed by the regional rep. Surprise! it didn't help. I suggested that while we are waiting on regional to come up with another guess they unplug the harness for the computer, the fuel injection and the ignition. Then clean them with contact cleaner, dry and reinstall. The service rep thought that was a good idea and will have that done while waiting on the response from regional. Thanks for all the great input.
 
fixed

I got my RT back yesterday, The final verdect? electrical gremlins. No one could find anything wrong with the bike even though all agreed it wasn't running right. Yesterday the mechanic working on it removed the software (erased the bios?) and reinstalled everything again. I took it out for a test ride and it runs like new.

Now I'm wondering if Microsoft wrote the programing. LOL
 
You must log in or register to reply here.

Similar threads

R
HELP OILHEAD EXPERTS! Bike dies after running 5 minutes.
Replies
19
Views
3K
RPGR90s
RPGR90s
exgman
Looking Back 70 Years / Analysis from the Boston GLOBE
Replies
12
Views
2K
6322
6322
O
Hello and thank you
Replies
11
Views
4K
oconcon
O
D
2006 K1200S Stranded me; diagnosis questions.
2
Replies
23
Views
16K
dobervol
D
N
Review from Bagger test drive @ The Chip in Sturgis
Replies
3
Views
4K
smeg
smeg
Back
Top