K11 Owners Group

atlantaboblutz@live.com · Posted: Sun Jul 07, 2013 8:39 pm Post subject: No start problem - Motronic code

Been wrestling with a no start problem on my '94 K11 for 6 weeks or so. Been through every diagnostic including several conversations with the duck-meister. After having replaced a BUNCH of things (fuel pump,fuel pressure regulator, fuel pump connector, new battery, all new fuel hoses, all vacuum leaks caused by old rubber fixed, ignition switch, rebuilt starter, new plugs, cleaned injectors, tested relays, tested connectivity ... even replacement Motronic) here's where I am. and yes,,,side stand switch has checked out.

I haven't posted on this previously until I did all the baseline home work, diagnostics, fixed the weak elements proactively, etc. myself.

Motronic sends ground to fuel pump relay just long enough for 12v to hit the fuel pump and injectors...but for no more than a second before it takes it away. Not long enough for fuel pump to start, let alone run for the normal 3-4 seconds.

That lead me to the HES which I know rarely fails and if so normally it degrades with heat. Here's the problem...

One of the sensors looks like it has a white burn streak on it. That said, when you do the LED test for signals - signals are sent by each of the HES's when the plane of the magnetic is open and signal stops when plane is broken by metal. This happens both by bench testing (using a feeler gauge to break the plane) and on the bike when spinning the starter. Wire continuity is good through end to end, so I know there is no break in the wire.

BUT... the bike still won't send power to the fuel pump long enough for it to fire. If I manually provide power to the new fuel pump...she pumps like she's made just for pumping. She's living the dream!.

So...what do the diagnostic codes from the motronic say. Glad you asked! I had the same question and hooked that little 'ol LED up to the diagnostic port to check that out (just to double check the temp gauge flashes).

That bugger says no signal from HES upper and no signal from HES lower. No other fault codes. In case you are curious about the codes.... it is just a 1122 and 1133 until it (or I) turn blue in the face.

Well, to be honest, it did initially say the throttle position sensor was out of spec... but then I remembered I didn't hook the TPS back up after checking continuity and whether it properly received 12v when the rest of the circuit was energized. Embarrassing oversight! Unplugged the motronic ... reconnected the TPS... and only codes remaining were upper and lower HES sensors. the 'ol 1122 and 1133.

BTW.. having read the warnings about "ghost" HES faults, again unplugged the motronic for a bit... then hooked it back up... and spun the engine so HES had every opportunity to send those little signals just a jumpin up through that connector to the Motronic. did that several times just to be sure.

Still the Motronic reports missing upper and lower HES.

So...could my HES be bad in some way... sending signal... but not enough to make the Motronic happy????

Did I mention I'm going nuts with sever motorcycle withdrawal symptoms?

Laughing

_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

Scott_Anderson · Posted: Sun Jul 07, 2013 9:24 pm Post subject:

atlantaboblutz@live.com · Posted: Sun Jul 07, 2013 10:14 pm Post subject: Wires

Yes, I'm aware of the injector sequence but energized that circuit just to make sure nothing odd was going on that would impact.

I did ck connectivity right back to pins on motronic connector & nothing burnt that I can find.

It's confounding that I can light an LED test light yet the motronic still not be happy with what it sees

I did find a source just for the Honeywell spec sensors rather than the crazy expensive BMW kit.
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

Scott_Anderson · Posted: Sun Jul 07, 2013 10:46 pm Post subject:

Another shot in the dark theory, when the starter is turning, actual motor is turning too? not just the starter spinning and the sprague clutch not engaging? Verified by checking compression.

I don't want to assume anything, which is why I'm asking. When you say you rebuilt the starter(or bought a rebuilt), they can be assembled backwards causing it to rotate in the reverse direction.

And the starter clutches have been known to not engage as well.
_________________
Ride safe.

1995 K1100LT 0302044
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)
1997 R1100RT ZC62149(sold)

atlantaboblutz@live.com · Posted: Mon Jul 08, 2013 7:29 am Post subject: tested direction

Well the "is the motor turning in the right direction" was a curve I hadn't thought of. First, to confirm, I rebuilt the starter myself because I wanted to test all of the sub-components along the way and ensure everything was cleaned up. But your "is it going backwards" gave me a pang of "well darned if I'm positive or not". So... how to test this out?

Well I put a block of wood under the centerstand to make certain the back wheel cleared. Of course the motor won't turn if it is in gear if the clutch isn't depressed. With the clutch depressed the wheel won't turn. So, I manually put the girl in 5th, spun the starter (and therefore motor) and popped the clutch. Well the wheel correctly spun forward - an indirect indication that the motor is spinning forward. We're good in that regard.

I was thinking though that since the Hall Sensors are 180 each other, then they would still send alternating signals regardless of the direction of motion. So maybe for specifically an HES perspective it might not matter the direction. Something to ponder a different day. But... in any case, I am spinning the motor in the correct direction.

I left an initial detail out. This all started when I dis-assembled the bike for a spline lube and general maintenance of the rear end. I got everything put together and the bike ran well with one exception... the rear brake wouldn't bleed properly. I took it to the local dealer... he got the rear brake working and I rode her home. Next day morning this "no start" problem surfaced. That started me down the track of checking all electrical connections since perhaps brake fluid contaminated some of them... and so the journey and expense began. At this point, I think the events were unrelated. But they are haunting nonetheless since it ran so well and then suddenly ... poof. But, components can and do fail at unexpected times.
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

whyoldbill · Posted: Mon Jul 08, 2013 10:50 am Post subject:

Hey Bob, this is probably a long-shot, but check that you have 2 heavy gauge ground cables connected to the negative terminal of your battery.

My 97 had very similar symptoms a couple years ago, although mine was intermittent.
After much hair pulling, I found that one of my ground cables had fallen between the battery box and the rear fender and I simply overlooked it when reconnecting the battery.

I hope it's that simple for you.
Regards,
Bill
_________________
'02 - GL1800

The desired effect is what you get when you improve your interplanetary funksmanship - George Clinton

atlantaboblutz@live.com · Posted: Mon Jul 08, 2013 11:09 am Post subject:

atlantaboblutz@live.com · Posted: Mon Jul 08, 2013 11:16 am Post subject: does anyone know???

since I know I have enough signal from the HES to light an LED... does anyone know how many mA the signal from the HES should be? Maybe mine is below whatever the threshold is so although the signal is generated ... it may be invisible to the Motronic. Long shot...
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

atlantaboblutz@live.com · Posted: Mon Jul 08, 2013 2:16 pm Post subject: Re: does anyone know???

Scott_Anderson · Posted: Mon Jul 08, 2013 5:41 pm Post subject:

This next one may be a bit of a stretch, can you open the motronic connector cover so that you can get at the wire connections when it's plugged in.
Where im going here is, can you connect your LED at the HES input terminals of the motronic while it's connected and check for signal when the motor is turning.
That should give you an idea if the HES is putting out enough current for the motronic to see it. If the sensors are putting out week(when disconnected), and then when connected the motronic should "pull" the signal down low enough that you might not be able to see it with the LED.

That's good news that you have the starter turning the right direction. If it wasn't the motor would not turn at all because the starter sprague clutch would not have engaged.
_________________
Ride safe.

1995 K1100LT 0302044
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)
1997 R1100RT ZC62149(sold)

atlantaboblutz@live.com · Posted: Mon Jul 08, 2013 6:14 pm Post subject: checked with second motronic

Well, just to be sure, I plugged my old motronic (original to the bike) just to make certain it was seeing the same thing. Sure enough, after clearing out clutter codes... I repeated the code scan and the only two coming up were upper HES followed by lower HES.

Although it continues to baffle me, it sure is appearing to be the HES. I did find a spec which states a 40mA current comes out of a currently available HES sensor replacement. So maybe the signal from the current sensors is weak???
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

atlantaboblutz@live.com · Posted: Mon Jul 08, 2013 8:19 pm Post subject:

I got an amp reading as the motor was spinning. I saw several 39, 40 and 42 readings flip by amongst 15's, 0's etc.

the LCD display on the meter or the meter itself likely struggles to keep up. So erroneous readings are likely the result of either ramp up or ramp down the signal curve readings. An o-scope would the path to a perfect result. The fact that the range of 39-42 showed among the readings is likely when the meter saw the peak. This leads me to believe the sensors are correctly producing the signal in the correct working range... in the neighborhood of 40 mA

So, I'm leaning that the prime suspect is elsewhere.
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

whyoldbill · Posted: Mon Jul 08, 2013 9:04 pm Post subject:

atlantaboblutz@live.com · Posted: Mon Jul 08, 2013 9:51 pm Post subject:

well, I swapped all of the "same spec" relays with no change. Relay flips for about 1 sec. I know that because I can both hear and feel it flip (if I put my finger on it) when I turn on the ignition.

I can read (just momentarily) 12v at the power feed at the connector to the fuel pump... and then it drops to zero... consistent with what you feel/hear at the relay.

So, a couple of things come to mind....

1) I was going to take apart the "backside" of the motronic connector to make sure everything is clean and if not... clean it. Not sure how to do that but can probably figure it out.

2) does the motronic need to see anything from the fuel sending unit? The pump does not prime if the tank is on the bike and all fuel line hooked up. But, it it expects something from the fuel sending unit, then it would fail BOTH with the tank off and with the tank off if the fuel sending unit has a break/short. I've seen low fuel light triggered and never had a fuel gauge issue so this is low probability.

3) perhaps there is something in the down stream ignition... coils, or fuel injection. I have tested the TPS and it tests "good" I don't think I have a fuel injection relay on this generation.

coils throw 12v right though to pin 19 on the montonic so that looks good. 12v to pin 20 on the motronic as well.

Does anyone know what feeds pin 30 on the Motronic?
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

Scott_Anderson · Posted: Mon Jul 08, 2013 10:07 pm Post subject:

I don't know what to think.
You have HES signal to the motronic, yet the motronic doesn't activate the fuel pump OR the ign coils..... Neither motronic works.......

Even the fuel pump "ign on" prime time isn't there.

If I lived a little closer I'd bring one of my bikes over for some parts swap trial and testing.

Do I dare ask where you got your "extra" motronic, are you sure it's a good one......
_________________
Ride safe.

1995 K1100LT 0302044
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)
1997 R1100RT ZC62149(sold)

atlantaboblutz@live.com · Posted: Tue Jul 09, 2013 11:17 am Post subject:

atlantaboblutz@live.com · Posted: Wed Jul 10, 2013 12:50 pm Post subject: Can someone run a quick test.

With the gas tank connector UNPLUGGED, can you put a volt meter on the BIKE SIDE of the plug, connected to the green/white terminal ... tell me how many seconds that you see 12v on that particular wire. It is important to try this with the tank completely disconnected.

Thanks...

tore everything out of the relay box to physically inspect all wires...everything looked good....unfortunately.
_________________
Thanks,
Bob
Atlanta GA

'94 K1100 LT
'76 R75/6

whyoldbill · Posted: Wed Jul 10, 2013 2:23 pm Post subject: Re: Can someone run a quick test.

atlantaboblutz@live.com · Posted: Wed Jul 10, 2013 3:44 pm Post subject: Re: Can someone run a quick test.

whyoldbill · Last edited by whyoldbill on Wed Jul 10, 2013 6:21 pm; edited 2 times in total