2002 R1150RT TPS Error Code

I'm helping a friend and fellow member with a 2002 R1150RT that is intermittently shutting down like it's been turned off, and not always restarting. The bike has had a new Hall sensor installed by the owner in the course of other work (clutch slave cylinder, alternator belt, brake flush) but had been exhibiting shutdown behavior before any of that work was started. Positioning of the Hall sensor and all pulleys was verified and timing checked out OK.

Aside from the Hall unit, the primary suspect has been the wiring harness up by the steering neck. That harness has been opened up--the green wire was showing serious damage so was replaced back to it's source on each end, and the red wire closely inspected but no damage was seen there.

The bike ran well for several days and a few hundred miles, then once again shut down and refused to restart. After retrieving the bike I checked for spark using a timing light (present) and read the codes with my GS-911, and found this:

288 "Throttle Position Sensor, Internal Fault on Upper or lower Potentiometer Slider. The fault is currently present."

The battery was then disconnected for 10 minutes or so, reconnected, and switched on so a TPS reset could be performed. After that the bike fired up and codes were cleared via GS-911. After a shutdown and subsequent restart the codes were read again and no faults were found.

I've not heard of common failures on the TPS sensors, and in this case the next step will be to trace the wiring from TPS to ECU, but my question is this: If the TPS signal is interrupted would the bike normally do an immediate shutdown or would it spit/sputter briefly before shutting down? I'd have expected a problem with the slider in the TPS would be a momentary issue that would be bypassed as the throttle was turned and the TPS pickup moved off the bad portion of the slider. Yes? No?

The next step is going to be to re-trace/re-inspect the wiring at the steering neck, bypass the sidestand switch, and possibly trace the wires and disable the engine cut-off switch then go for a long test ride and burn a tank of gas or two. If no shutdowns are experienced then the two switches can be reconnected one at a time and the test repeated--the owner doesn't mind doing test rides so long as I'm available to retrieve him with a trailer.

Any other suggestions would be welcomed!

Best,
DeVern

I used the google site search tool and came up with a couple of threads that might be worth reading:

https://forums.bmwmoa.org/showthread.php?57043-GS-911-Fault-Codes-(2002-R1200C)

https://forums.bmwmoa.org/showthread.php?95013-Bad-TPS-17K-miles-R1150RS

DeVern,

When you say “shutdown”, do you mean all dashboard lights off, like all electrical power gone? Or is it more like the engine stalled?

This is an early 1150. Is this a single spark or dual spark motor? Stick coils or central coil?

When it fails, is it dead electrics. Turn the key On, does the fuel pump cycle, do the dash lights come on? Does the starter motor turn the motor over? Tested for fuel coming out of the injectors?

m_stock10506 said:

DeVern,
When you say “shutdown”, do you mean all dashboard lights off, like all electrical power gone? Or is it more like the engine stalled?

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All lights and dash indicators function as normal-engine just suddenly stops running.

m_stock10506 said:

This is an early 1150. Is this a single spark or dual spark motor? Stick coils or central coil?

Click to expand...

Single spark, central coil

m_stock10506 said:

When it fails, is it dead electrics. Turn the key On, does the fuel pump cycle, do the dash lights come on?

Click to expand...

. Fuel pump and ABS both initialize normally, all lights and indicators function normally.

m_stock10506 said:

Does the starter motor turn the motor over?

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Motor cranks but does not fire, one reason the SS switch is on the suspect list. An inductive timing light does show spark activity present while cranking.

m_stock10506 said:

Tested for fuel coming out of the injectors?

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That test is scheduled for the next shutdown event. Unfortunately, that may be a while as my friend is joining me for a ride to the National on his other bike, and then has family commitments for several weeks after the rally.

Best,
DeVern

Your answers are very helpful. They clear up most of what’s happening.

Early 1150 bikes still had the hall sensor plate with the bad wiring harness. Even if that isn’t the primary reason for the problem, I would replace or repair the wiring if this is the bad wiring harness. GSAddict is on this forum and he repairs the HES. He has a great photo that shows the difference between the bad and the good factory harness. But, a hall sensor wiring harness problem doesn’t usually go away and come back repeatedly.

The sudden stop and won’t restart sounds more like a problem coil. I know folks say that the single coil rarely fails, but I replaced the coil in my 1100RT, and two friends also replaced coils in theirs.

Response from bike owner

m_stock10506 said:

Your answers are very helpful. They clear up most of what’s happening.

Early 1150 bikes still had the hall sensor plate with the bad wiring harness. Even if that isn’t the primary reason for the problem, I would replace or repair the wiring if this is the bad wiring harness. GSAddict is on this forum and he repairs the HES. He has a great photo that shows the difference between the bad and the good factory harness. But, a hall sensor wiring harness problem doesn’t usually go away and come back repeatedly.

The sudden stop and won’t restart sounds more like a problem coil. I know folks say that the single coil rarely fails, but I replaced the coil in my 1100RT, and two friends also replaced coils in theirs.

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I'm the bike owner and I just replaced the HES using a GSAddict unit. Appreciate all the help, especially from GTRider!

rrfullmer said:

I'm the bike owner and I just replaced the HES using a GSAddict unit. Appreciate all the help, especially from GTRider!

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Great to hear the outcome
OM

Response from bike owner #2

New HES and wiring. New ignition coil, wiring and plugs. The bike still kills when after 5 minutes or when the temp rises above 3 bars on the indicator. TPS error means new/used TPS. Maybe ECU? Maybe I'm out to lunch? Help please!

Go back to the beginning, grounds, fuses(actually pull them and check), make sure relays are seated, air filter, fuel filter, battery good, charging good, not too many keys on your key ring.

TPS is very robust on our bikes this vintage.

HES could be a culprit even though wiring is good. It needs a few things beyond wiring to work properly.

As a friend reminded me last night, take everything you know, ignore it and start over.

Just repaired an old John Deere that was a real mosquito killer by removing almost 2 quarts of oil from an overfilled crankcase.

Wadda ya alz think? 2 minutes or less to pull dipstick, another 2 to pull the excess, runs great but I will change the air filter.

Thinking less than hour to get 'er back to shape but I need consideration for my time. $4,000.00 to replace rings/pistons and so on or $500.00 for my time our a gift because the mantra, "keep it simple, stupid" is priceless.

rrfullmer said:

New HES and wiring. New ignition coil, wiring and plugs. The bike still kills when after 5 minutes or when the temp rises above 3 bars on the indicator. TPS error means new/used TPS. Maybe ECU? Maybe I'm out to lunch? Help please!

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TPS error means new/used TPS? Please explain what that means.

I have a '04 RT and my GS911 showed my TPS was ok, per it showing it in the green on the graph.

I was having intermittent stalling, poor idle issues, so I checked it with a ohmmeter, and found inconsistent resistance values across it's range.

It was replaced, bike has never run better.