And it had been running so well....

'04 RT, 102k, recently started idling poorly. It hasn't been serviced since last fall.

I installed a AFxied Lambda adapter (setting 7)last year and it's been running great up until recently.

Symptoms:

Hard to start. If I add more throttle than the fast idle lever, it will start, but only idles around 600 rpm and wants to stall. At speed, it runs fine, no issue. But idle speed is way down and it's rough even when warm.

I'll pull the panels off soon as it's due for an oil change/throttle body cleaning.

I hooked up my GS911 and it had a "4400: Lambda-Control, Lower control limit reached", which wasn't present at the moment but had occurred 82 times previously.

Bad O2 sensor possibly?

thanks,

RPG

'04 RT, 102k, recently started idling poorly. It hasn't been serviced since last fall.

 

I installed a AFxied Lambda adapter (setting 7)last year and it's been running great up until recently.

 

Symptoms:

Hard to start. If I add more throttle than the fast idle lever, it will start, but only idles around 600 rpm and wants to stall. At speed, it runs fine, no issue. But idle speed is way down and it's rough even when warm.

 

I'll pull the panels off soon as it's due for an oil change/throttle body cleaning.

 

I hooked up my GS911 and it had a "4400: Lambda-Control, Lower control limit reached", which wasn't present at the moment but had occurred 82 times previously.

 

Bad O2 sensor possibly?

 

thanks,

 

RPG

Morning Rick

I'm on my way to a meeting so don't have much time to put into this response (will come back & add more later if needed).

On the o2 sensor being the starting low cold idle issue-- possible but unlikely. The o2 sensor by itself has no effect on starting fueling BUT if it is acting up it could skew the adaptives enough to effect starting commanded fueling. As a quick test just remove fuse 5 overnight, then next morning re-install fuse 5, do a new key-on TPS re-learn, then start as normal (this will re-set all the stored adaptives & give a fresh slate for starting. If it starts & cold idles better then possibly an o2 issue.

Your problem sounds more like fouled spark plug or a stick coil issue so possibly look into that area. If a fouled lower spark plug they can start harder & definitely have a lower poorer idle but still run OK going down the road.

If your problem just popped up out of no-where & it isn't a fouled spark plug or a bad stick coil then suspect a tank of fuel that has a very high alcohol content (run your tank low then fuel up with non alcohol fuel (you still riding out to Lansing area for work?, if so then the Sunoco station in Brighton has 91 octane non alcohol gasoline).

morning D.R.

The problem has been slowly getting worse over the last week or so. I've had a few tanks of fuel in that time, so my gut thinks it's not the fuel. We just moved to the Irish Hills area (s. of Jackson), and the local BP has non-ethanol fuel so I'll try that next tank to get a baseline.

10-4 on the fuse 5 removal. I'll do that this evening and check it in the morning.

I did insert my spark plug tester tool on the left side stick coil and it flashes. Not the greatest designed tool IMHO as it was tough to get the one end seated on the central plug. I couldn't get it locked in on the right side, but I'll try again tonight.

I'll have the panels off when my shipment of Amsoil arrives and I'll know further after checking out the lower plugs.

Thanks as always.

btw, soooo many nice roads out this way and a much better ride to the Lansing area than from Dee-Toilet.

RPG

'04 RT, 102k, recently started idling poorly. It hasn't been serviced since last fall.

 

I installed a AFxied Lambda adapter (setting 7)last year and it's been running great up until recently.

 

Symptoms:

Hard to start. If I add more throttle than the fast idle lever, it will start, but only idles around 600 rpm and wants to stall. At speed, it runs fine, no issue. But idle speed is way down and it's rough even when warm.

 

I'll pull the panels off soon as it's due for an oil change/throttle body cleaning.

 

I hooked up my GS911 and it had a "4400: Lambda-Control, Lower control limit reached", which wasn't present at the moment but had occurred 82 times previously.

 

Bad O2 sensor possibly?

 

thanks,

 

RPG

To DR's always good list, I would add that the 4400 error you're seeing is caused by the Motronic not being able to add or remove enough fuel to hit 14.7:1 or in your case about 14:1 (and for anyone who still doubts that the Motronic is a learning/adapting ECU, this is proof that it is). Several things can cause that: a leaking in tank hose, or other cause for low fuel pressure. You can check that with a return volume test. Any significant misfiring can also lead to excess oxygen that the Motronic is unable to add enough fuel to correct (not that more fuel is the answe to misfiring). It could also be your O2 sensor is weak but that would be last on my list. Clear the errors and see if they come back while you work on DR's list.

morning D.R.

 

The problem has been slowly getting worse over the last week or so. I've had a few tanks of fuel in that time, so my gut thinks it's not the fuel. We just moved to the Irish Hills area (s. of Jackson), and the local BP has non-ethanol fuel so I'll try that next tank to get a baseline.

 

10-4 on the fuse 5 removal. I'll do that this evening and check it in the morning.

 

I did insert my spark plug tester tool on the left side stick coil and it flashes. Not the greatest designed tool IMHO as it was tough to get the one end seated on the central plug. I couldn't get it locked in on the right side, but I'll try again tonight.

 

I'll have the panels off when my shipment of Amsoil arrives and I'll know further after checking out the lower plugs.

 

Thanks as always.

 

btw, soooo many nice roads out this way and a much better ride to the Lansing area than from Dee-Toilet.

 

RPG

Morning Rick

Yes, Irish Hills is a super riding area but lately that area seems to have a lot of traffic except for very early in the morning (I have a friend that lives on Wamplers Lake). You did pick a great place to move to (well except for Nascar weekends).

As for a coil test-- see if it will run on JUST the lower plugs, then see if it will run on JUST the upper plugs.

I'm just west of Wamplers off of 12 (Lake LeAnn).

thanks for the tip on the plugs. I'll verify with that test.

Thanks very much!

RPG

the other thing I wanted to mention is that my GS911 indicated battery voltage at less than 9vdc. But checking the battery with my Fluke, indicated a normal 13.6vdc.

thanks,

RPG

the other thing I wanted to mention is that my GS911 indicated battery voltage at less than 9vdc. But checking the battery with my Fluke, indicated a normal 13.6vdc.

 

thanks,

 

RPG

Afternoon Rick

The GS-911 gets it's battery voltage from system voltage as it obviously has no direct access to the battery posts.

This could be telling us something-- like the large red wire at the battery (+) post has a high resistance connection (is it corroded looking or just hanging by a thread?)

Of some other high resistance area in the wiring harness (like an internal solder connection or a partially broken wire near the steering neck).

Or even a negative side connection corrosion issue.

Run another GS-911 test & if it still shows low then use a good digital DC volt meter & start checking voltage points and/or voltage drops on each circuit including the ground side. Maybe look at voltages at all the ign & battery fed fuses. If you find a low one then that might point to where to start looking, circuit wise.

9 volts to the coils or fuel injectors could surly cause bad or low cold idle.

My 04 RT had a large drop across the key switch. It powers three coils.

the other thing I wanted to mention is that my GS911 indicated battery voltage at less than 9vdc. But checking the battery with my Fluke, indicated a normal 13.6vdc.

 

thanks,

 

RPG

 

Afternoon Rick

 

The GS-911 gets it's battery voltage from system voltage as it obviously has no direct access to the battery posts.

 

This could be telling us something-- like the large red wire at the battery (+) post has a high resistance connection (is it corroded looking or just hanging by a thread?)

 

Of some other high resistance area in the wiring harness (like an internal solder connection or a partially broken wire near the steering neck).

 

Or even a negative side connection corrosion issue.

 

Run another GS-911 test & if it still shows low then use a good digital DC volt meter & start checking voltage points and/or voltage drops on each circuit including the ground side. Maybe look at voltages at all the ign & battery fed fuses. If you find a low one then that might point to where to start looking, circuit wise.

 

9 volts to the coils or fuel injectors could surly cause bad or low cold idle.

 

 

Morning D.R.

I have the panels off so tonight I'll do some investigating.

The steering head harness (ignition switch) was repaired about six years ago after the power wire was frayed and hasn't been an issue since, AFAIK. But that bears an inspection again.

Appreciate the info.

RPG

My 04 RT had a large drop across the key switch. It powers three coils.

thanks Roger

Because of the voltage drop and natural short dwell time of the 1150 dual spark I added a second load relay to power them from the battery. It's not a hard job and I noticed that the engine was smoother, right away.

Because of the voltage drop and natural short dwell time of the 1150 dual spark I added a second load relay to power them from the battery. It's not a hard job and I noticed that the engine was smoother, right away.

Roger, you mean a 2nd relay in addition to the one already powering the lower plugs?

thanks,

RPG

Rick, I don't think there is a relay for the lower plugs. That coil power runs right to ignition switch (as does the +12V for the stick coils on many dual sparks). The relay I'm talking about is something called a 2nd Load Relay that BMW added mid way through the '04 production run that powers the stick coils separately. If you have it it is usually located to the left of the Coding Plug in the electrical box.

Rick, I don't think there is a relay for the lower plugs. That coil power runs right to ignition switch (as does the +12V for the stick coils on many dual sparks). The relay I'm talking about is something called a 2nd Load Relay that BMW added mid way through the '04 production run that powers the stick coils separately. If you have it it is usually located to the left of the Coding Plug in the electrical box.

HI Roger, I'm certain I have that as there is a relay to the left of the coding plug. I've verified the relay is good. Other tests to commence this evening.

Thanks,

RPG

Afternoon Rick

Here is the 2nd load relief (upper coil) power relay.

Afternoon Rick

 

Here is the 2nd load relief (upper coil) power relay.

 

 

Afternoon D.R.

Yes sir. I gots one a them in my RT. If I recall, my RT was built May or June of 2004.

Last night I was able to check spark on main and lower plugs. Spark is fine, lower plugs were oil fouled. Main's were replaced with Autolite's, lower's with NGK.

I pulled fuse 5 and let it sit over-night. It starts and idles better. I ran another GS911 log before removing fuse 5 and it's still showing low battery voltage. I'll start probing further this evening. Battery cables are clean and tight. Ground is good between left throttle body and engine case.

I see in the log at 193.232 sec, the Lambda closed loop control goes back to Open? Not sure why that would happen.

I'll share more after looking for the low voltage source. Battery voltage is 12.79 at rest, 13.98 when idling.

6967.txt

Last night I was able to check spark on main and lower plugs. Spark is fine, lower plugs were oil fouled. Main's were replaced with Autolite's, lower's with NGK.

 

I pulled fuse 5 and let it sit over-night. It starts and idles better. I ran another GS911 log before removing fuse 5 and it's still showing low battery voltage. I'll start probing further this evening. Battery cables are clean and tight. Ground is good between left throttle body and engine case.

 

I see in the log at 193.232 sec, the Lambda closed loop control goes back to Open? Not sure why that would happen.

 

I'll share more after looking for the low voltage source. Battery voltage is 12.79 at rest, 13.98 when idling.

Afternoon Rick

Yes, something going on with that battery voltage-- I have an older GS-911 data dump (I'm pretty sure it was from you as I have it labeled RPG ) & it shows 12 to 14 volts where you show 9 & 10 volts now.

That open loop might be due to the o2 sensor cooling off as the internal o2 heater might not be getting enough current to heat properly (I stress might on this as it is just a guess).

See what your upper coil voltage, fuse #5 voltage, fuel injector voltage, & o2 sensor heater voltage is running when you are seeing the 9 & 10 volts on the GS-911. In fact see what the voltage is on all fuses when you are seeing 9 to 10 on your GS-911. If you look at the fuses there should be a little window on each end of the top surface with a little metal in that window (allows a voltage probe of both sides of fuse with fuse still installed). Not all fuses have this feature but if yours do then it makes it real easy to do voltage probes.

If you can get to it see what the voltage is going into the ignition switch then coming out of the ignition switch (might tell us something).

Also-- look to make sure that your o2 sensor pig tail isn't hanging down & contacting the hot exhaust.

I also think we need to get Roger involved with this one.

Last night I was able to check spark on main and lower plugs. Spark is fine, lower plugs were oil fouled. Main's were replaced with Autolite's, lower's with NGK.

 

I pulled fuse 5 and let it sit over-night. It starts and idles better. I ran another GS911 log before removing fuse 5 and it's still showing low battery voltage. I'll start probing further this evening. Battery cables are clean and tight. Ground is good between left throttle body and engine case.

 

I see in the log at 193.232 sec, the Lambda closed loop control goes back to Open? Not sure why that would happen.

 

I'll share more after looking for the low voltage source. Battery voltage is 12.79 at rest, 13.98 when idling.

 

Afternoon Rick

 

Yes, something going on with that battery voltage-- I have an older GS-911 data dump (I'm pretty sure it was from you as I have it labeled RPG ) & it shows 12 to 14 volts where you show 9 & 10 volts now.

 

That open loop might be due to the o2 sensor cooling off as the internal o2 heater might not be getting enough current to heat properly (I stress might on this as it is just a guess).

 

See what your upper coil voltage, fuse #5 voltage, fuel injector voltage, & o2 sensor heater voltage is running when you are seeing the 9 & 10 volts on the GS-911. In fact see what the voltage is on all fuses when you are seeing 9 to 10 on your GS-911. If you look at the fuses there should be a little window on each end of the top surface with a little metal in that window (allows a voltage probe of both sides of fuse with fuse still installed). Not all fuses have this feature but if yours do then it makes it real easy to do voltage probes.

 

If you can get to it see what the voltage is going into the ignition switch then coming out of the ignition switch (might tell us something).

 

Also-- look to make sure that your o2 sensor pig tail isn't hanging down & contacting the hot exhaust.

 

I also think we need to get Roger involved with this one.

10-4. I will get back on it this evening. I didn't have time to pull the tank last night. Like I said, I did install a AFXied last fall. It DOES give the proper blinks when running (currently set to 7), but I wanted to check the connections anyway (behind the tank). And removing the tank allows me to look at the ignition switch wiring much easier.

Thanks very much as always!

RPG

I will look at the log later but my inclination is to find out why the GS-911 is reporting low voltage. I believe it measures after fuse 5 at the diag connector because it reads voltage even with the key off.

So I would put my negative dvm lead on battery negative and then measure the voltage at the diag connector: the ground pin, the red/yellow wire and the blue (D+) wire.

I looked over your data, other than the O2 voltage not varying and the low battery voltage it's fine. The Motronic went open loop when you dropped the fast idle lever, then you moved the throttle so it took a while to regain closed loop. It's possible your TB sync is a bit off but don't worry about that now. Let's figure out why that battery voltage reading is so low. Then we can figure out why the O2 voltage doesn't vary in closed loop.

 

10-4. I will get back on it this evening. I didn't have time to pull the tank last night. Like I said, I did install a AFXied last fall. It DOES give the proper blinks when running (currently set to 7), but I wanted to check the connections anyway (behind the tank). And removing the tank allows me to look at the ignition switch wiring much easier.

 

Thanks very much as always!

 

RPG

Afternoon Rick

This in addition to what Roger posted not in place of.

If you are removing the fuel tank then you have many more options. So you might have a better chance of isolating the voltage drop area.

When your GS-911 is showing that the low voltage problem is present measure voltage from battery (-) post to fuse #3, #5, #6, #10 -- If ALL of those fuses show low voltage then suspect a high resistance problem right at the battery where the smaller red wire attaches.

If only one or two show low voltage or they all show different voltages then suspect a problem in the solder joint (inside the main harness) where the red B+ wires are all tied together.

If the voltages at fuse #3, #5, #6, #10 all show reasonably close to battery voltage but your GS-911 still shows it low then re-measure the fuse #3, #5, #6, #10 voltage, only this time instead of using the battery (-) post as the ground base use the engine block (good clean connection to that). If the fuse voltage shows OK using the battery (-) post as the base ground connection but it shows low using the engine block as the base ground then suspect a grounding issue at the negative battery post or at the engine block (very difficult to get to).

If no smoking gun is found then to add to Rogers suggestions above measure the voltage from fuse #3, #5, #6, #10 but use the brown wire at the diagnostic connector as the base ground point for your voltmeter (this should verify that the GS-911 is seeing close to the same ground potential as the battery (-) post)

Good morning Gentlemen,

I did some further testing last evening, but my ground point was the engine case, not battery ground. I did verify consistent voltage across all 10 fuses, although one of the pins on the diagnostic connector was reading 2 vdc lower. It was late and I didn't have my schematic to get the color code, but I'll be back at it this evening.

Thanks for the additional information. I appreciate the detailed steps and I'll provide answers at my earliest convenience.

I'm thankful for the GS911 as if it wasn't for the low battery voltage, I would have put the panels back on, the bike is at least starting and idling fairly normal again, after the spark plug change.

RPG

Good morning Gentlemen,

 

I did some further testing last evening, but my ground point was the engine case, not battery ground. I did verify consistent voltage across all 10 fuses, although one of the pins on the diagnostic connector was reading 2 vdc lower. It was late and I didn't have my schematic to get the color code, but I'll be back at it this evening.

 

Thanks for the additional information. I appreciate the detailed steps and I'll provide answers at my earliest convenience.

 

I'm thankful for the GS911 as if it wasn't for the low battery voltage, I would have put the panels back on, the bike is at least starting and idling fairly normal again, after the spark plug change.

 

RPG

Morning Rick

That lower voltage pin at the diagnostic connector might have been the D+ (blue wire) as that circuit comes though the dash warning light resistance do depending on the load would measure a little lower voltage.

Good morning Gentlemen,

I did some further testing last evening, but my ground point was the engine case, not battery ground. I did verify consistent voltage across all 10 fuses, although one of the pins on the diagnostic connector was reading 2 vdc lower. It was late and I didn't have my schematic to get the color code, but I'll be back at it this evening.

Thanks for the additional information. I appreciate the detailed steps and I'll provide answers at my earliest convenience.

I'm thankful for the GS911 as if it wasn't for the low battery voltage, I would have put the panels back on, the bike is at least starting and idling fairly normal again, after the spark plug change.

I also see the O2 sensor voltage not fluctuating correctly, but the bike wasn't fully warm either. (only 160F). I'll graph that out on a warm engine.

RPG

Morning Rick

That lower voltage pin at the diagnostic connector might have been the D+ (blue wire) as that circuit comes though the dash warning light resistance do depending on the load would measure a little lower voltage.

afternoon D.R.

I was just looking at the schematic and saw the D+ connection to the alternator and I agree. thanks for clarifying.

RPG

Afternoon Rick

To BE SURE that you are catching the problem, are you measuring the fuse voltages with the GS-911 hooked up & also reading low voltage?

If a load on the battery circuit is not applied then it's possible that your open circuit voltage could measure close to good. (your meter alone won't put much of a load on a circuit).

The GS-911 takes its voltage reading from the Red/Yellow wire in the diagnostic connector--I just went and checked. That wire is connected to the fused side of fuse 5. The most likely thing causing that low voltage reading is either a high resistance fuse 5 or a grounding problem. As DR said you want the GS-911 attached when you're making the readings.

When I attach the GS-911 to my 2001 R1150GS. I can get a voltage reading on the GS-911 without turning the key on, using the iPhone app. You might try that first and see what voltage it reads. Then you could start the bike and see if the GS-911 reading changes. And at each step you can compare what the GS-911 reads to what you read with your DVM.

Thanks Gentlemen,

No, I was checking voltages last evening with the GS911 disconnected. But I'll connect and start testing.

Thanks,

Thanks Gentlemen,

 

No, I was checking voltages last evening with the GS911 disconnected. But I'll connect and start testing.

 

Thanks,

Evening Rick

If the GS-911 battery voltage doesn't show low just hooked to the diagnostic connector then try it with both key-on, & with engine running. Upper coils, fuel injectors, ign switch, headlight, fuel pump, Motronic, etc, about all accessories, are powered from the same red wire connected to the battery (+) post. All those things place a heavy load on the root of the B+ supply circuit.

Afternoon Rick

This in addition to what Roger posted not in place of.

If you are removing the fuel tank then you have many more options. So you might have a better chance of isolating the voltage drop area.

When your GS-911 is showing that the low voltage problem is present measure voltage from battery (-) post to fuse #3, #5, #6, #10 -- If ALL of those fuses show low voltage then suspect a high resistance problem right at the battery where the smaller red wire attaches.

Ignition off, connected to battery -, measurements are consistent @12.69vdc.

If only one or two show low voltage or they all show different voltages then suspect a problem in the solder joint (inside the main harness) where the red B+ wires are all tied together.

If the voltages at fuse #3, #5, #6, #10 all show reasonably close to battery voltage but your GS-911 still shows it low then re-measure the fuse #3, #5, #6, #10 voltage, only this time instead of using the battery (-) post as the ground base use the engine block (good clean connection to that). If the fuse voltage shows OK using the battery (-) post as the base ground connection but it shows low using the engine block as the base ground then suspect a grounding issue at the negative battery post or at the engine block (very difficult to get to).

Ignition off, connected to engine case, almost identical readings across the fuses @12.68vdc

If no smoking gun is found then to add to Rogers suggestions above measure the voltage from fuse #3, #5, #6, #10 but use the brown wire at the diagnostic connector as the base ground point for your voltmeter (this should verify that the GS-911 is seeing close to the same ground potential as the battery (-) post)

Ignition off, again, nearly identical readings across all fuses when DVM - is connected to brown diag. connector, reading 12.68vdc

With GS911 connected and ignition on, fuse voltage checks are 12.69vdc, whether connected to engine ground, or battery ground.

GS911 registers 10.41vdc, ignition on, engine not running

GS911 registers 11.14vdc, engine running

I didn't open up the ignition switch harness yet, but I believe it has to be good as measuring voltage across the battery is nearly identical as measuring across the fuses. No?

Roger, I have a PC version of the GS911, which requires ignition on to get any readings. Fuse 5 measures .1 ohms

 

With GS911 connected and ignition on, fuse voltage checks are 12.69vdc, whether connected to engine ground, or battery ground.

 

GS911 registers 10.41vdc, ignition on, engine not running

GS911 registers 11.14vdc, engine running

I didn't open up the ignition switch harness yet, but I believe it has to be good as measuring voltage across the battery is nearly identical as measuring across the fuses. No?

 

Morning Rick

All your tests seem to indicate no problem with your bike's side of the system.

So that pretty well leaves a GS-911 issue or a problem in the power or ground circuits at the diagnostic connector. (ground side at diagnostic connector seems to test good with JUST the voltmeter load but it might act up with the GS-911 load on it).

So check the voltage with key-on at the diagnostic connector between the Red/Yellow (B+) wire & the Brown (Ground) wire, if those are close to battery voltage (over 12v anyhow) then suspect your GS-911 is reading incorrectly. Or, maybe re-test again by putting a small light bulb or test light in parallel with the voltmeter to simulate a load as that could show a resistance problem that your voltmeter load alone might not.

If it points to a GS-911 problem then try that on another BMW to see if also reads low on that bike.

Good afternoon D.R.,

I agree. All the voltage checks I've made on the bike side are good. Per your request, voltage at the Red/Yellow and Brown wire on the diag. connector reads an exact battery voltage.

My buddy is riding around L. Superior this week (K1300GT), and I've run diagnostics on his bike before, so I'll hook it up when he returns and then get a hold of the GS911 folks from there.

I would like to get it addressed as several tests are unavailable if the "system" reads low voltage; TPS adjustment being one of them.

Otherwise, the bike runs perfect again. Thanks to you and Roger04 for your guidance. And per Roger's tip, the throttle bodies were slightly out of balance. All good now, clean LBBS's too.

Rick

Good afternoon D.R.,

 

I agree. All the voltage checks I've made on the bike side are good. Per your request, voltage at the Red/Yellow and Brown wire on the diag. connector reads an exact battery voltage.

 

My buddy is riding around L. Superior this week (K1300GT), and I've run diagnostics on his bike before, so I'll hook it up when he returns and then get a hold of the GS911 folks from there.

 

I would like to get it addressed as several tests are unavailable if the "system" reads low voltage; TPS adjustment being one of them.

 

Otherwise, the bike runs perfect again. Thanks to you and Roger04 for your guidance. And per Roger's tip, the throttle bodies were slightly out of balance. All good now, clean LBBS's too.

 

Rick

 

Afternoon Rick

Did you put a little load (like a 12v test light) across the Red/Yellow and Brown at the diag. connector before measuring the voltage at the Red/Yellow and Brown wire on the diag. connector?

Digital meters put such a small load on a circuit that it can measure good voltage even with some series resistance in the circuit.

Hi D.R.,

I did just that actually.

Hi D.R.,

 

I did just that actually.

Rick,

Is everything back to normal with your bike?