Error 16

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Wanderer

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I'll preface this with: I'm gonna assume it's my fault, it always is.

So after a very long winter break, my new WestCo battery arrives and I haul it to the garage to put it in. I'm extremely embarrased to admit that I bumbped the ratchet against a forkleg and got some good sparks for the briefest of seconds. It didn't even leave a pit. After a good but of self berating I finish the install. Quick check on the the Datel and it reads 12.9v. OK...Bike on, fuel pump whirrs, I thumb the starter, it spins strong. But it doesnt start.

I'll spare you the mundane basic troubleshooting, but I realize I smell gas, musta flooded it somehow. No Probs, I have 4 NGK Iridiums, so I stick them in real fast. Yep, old plugs are wet. Hmm.

Thats when I notice the error code 16

From the Yamaha manual:

Error Code 16

A stuck throttle position sensor is

detected.

Or,

Faulty intake air pressure sensor pipe

system; a hose is detached, causing

constant application of the atmo-

spheric pressure to the sensor; or, the

hose is clogged.

Probable Causes:

• Open or short circuit in wiring sub lead.

• Open or short circuit in wiring harness.

• Defective sensor (stuck throttle position sensor).

• Intake air pressure sensor hose is detached, clogged,

kinked, or pinched.

• Malfunction of the intake air pressure sensor in the interme-

diate electrical potential.

• Malfunction of the atmospheric pressure sensor in the inter-

mediate electrical potential.

• Malfunction in ECU

Ok so, flooded smell, wet plugs, code 16. Throttle bodies are stuck wide open, seems pretty basic.

I've disconnected the wiring harness to the tank(no fuel pump) and spin the starter, after about 5 seconds it catches and *would* start, were there fuel to continue the combustion. So, its definately the TPS is sticking the throttle bodies wide open.

Everything points to the Stuck TPS but the bullets about the wire harness short and ECU malfunction scare the f%$k outta me especially in conjunction with the aformentioned sparks.

So the real question: What did I break, How did I break it, and How do I fix it?

Once again, I bow to you FJR gurus.

 
Ok so, flooded smell, wet plugs, code 16. Throttle bodies are stuck wide open, seems pretty basic. I've disconnected the wiring harness to the tank(no fuel pump) and spin the starter, after about 5 seconds it catches and *would* start, were there fuel to continue the combustion. So, its definately the TPS is sticking the throttle bodies wide open.

Everything points to the Stuck TPS but the bullets about the wire harness short and ECU malfunction scare the f%$k outta me especially in conjunction with the aformentioned sparks.

So the real question: What did I break, How did I break it, and How do I fix it?
Just so you get your head around the concept, the TPS doesn't control the position of the throttle plates in the throttle bodies. Your right hand does. The throttle plates in the FJR's injection system work just like throttle plates on a carb. The TPS measures how far the throttle plates inside the throttle bodies are opened, relative to 0=closed, 100=wide open. By measuring the amount the throttle plates are open, controlled by the right handgrip, the ECU knows how much fuel to inject into the motor, hence the name Throttle Position Sensor. The TPS only measures throttle plate movement. It doesn't control the position of the plates.

So stop thinking that the code 16 means your throttles are wide open. Don't want "wrong" thinking to lead you to making incorrect assumptions.

You didn't say if you attempted another restart after re-plugging your fuel pump....did you attempt to re-crank it?

My personal suggestion at this point would be to enter the diagnostic sequence, as outlined in the FSM, reset the Code 16, attempt a restart with everything plugged back in, and see if the code comes back. And remember, if you really flooded the motor badly, it still might require a restart attempt with WOT, i.e., Wide Open Throttle, to help clear excess gas that may remain in the cylinder. Putting in dry plugs was a good idea.

 
RH,

Good info. in my freaked out state I never stopped to realize that the plates are actuated by wire while the TPS is an electronic monitor. Makes sense.

In response to your post, I tried several unplugs-replugs/restarts of the plugs in the bottom of the tank after I read the code would go away once the condition wasnt detected anymore. I also unplugged several other things in an attempt to find an reset the TPS. It came up with more error codes that were alleviated when the connections were restored. (13 and 14) I even undid the 2 screws that attaches the fitting from the fuel line to the fuel rail and turned on the key. Fuel Pump works good. =D

My main concern having mulled it over for an while is still the flooding issue. If the pump is off and thus doesnt fill the rail, the bike will sorta start which tells me that its running off the residual fuel in the rail/TB's. I confirmed this by doing it 3 times. All three ended the same. As soon as the fuel pump is working, the system gets a ton of fuel and it gets flooded. Tried this twice more in sequence with the no fuel pump scenario.

Something is allowing the cylinders to recieve way too much fuel.

 
Last edited by a moderator:
I should have paid closer attention to your personal info sooner.

I see you have an '03 FJR. Have you had your TPS recall done? Maybe you actually DO have a TPS issue that's reporting incorrect throttle position values to the ECU, causing too much fuel to be injected, resulting in flooding.

I'd suggest going into the DIAG mode as per the FSM and check your TPS operation. My FSM is at the office, so I don't have access to the sequence at the moment, but when you enter the correct code value, you sould see 15 to 17 on the display with the throttle at idle position, and 95-97 in WOT position. Plus, reading the DIAG screen while SLOWLY operating the throttle from idle position to WOT, you should see a smooth increase in the display numbers with no jumps or gaps in the numbers as the throttle rotates. AND the number should increase while you turn the throttle.

If you see the numbers jump around up/down/up/down while turning the throttle, you're seeing a bad TPS -- a known problem item, hence the factory recall.

 
Went back to work on the bike this morning:

03'Silver: Connectors look good. I took apart ALOT of them just to make sure.

RH: Diag TPS reads 15 at 'idle' and 100 at WOT, smooth and linear all the way up so I guess thats out. The TPS recall was done.

To further the diagnostics, the first thing I did this morning was try to crank it. Having sat all night on the centerstand it came very close to starting. It quickly started smelling of gas, including at the exhaust.

I reset the code and tried starting it again. the code didn't reappear in the 2-3 times I turned on/off the key but it still floods.

 
Update:

I guess I fixed it.

I disassembled and cleaned everything between the fuel pump and the throttle plates in the TB's. didnt see any varnish or debris but you never know.

Reassemebled everything and after a few tries she fired up so I went for a 25-30 mile ride Still idles a bit rough, but I believe that to just be old gas.

I'm not sure exactly what I fixed, but a thorough cleaning of the FI system seems to have done it.

 
I'll preface this with: I'm gonna assume it's my fault, it always is.
So after a very long winter break, my new WestCo battery arrives and I haul it to the garage to put it in. I'm extremely embarrased to admit that I bumbped the ratchet against a forkleg and got some good sparks for the briefest of seconds.
I didn't hear any of the FJR guru's mention this, so let me suggest that in the future you disconnect the negative terminal first to avoid any unitentional "welding" on the bike. :dribble:

 
For future reference on any computer controlled motor vehicle when disconnecting the battery you should always dissconnect the negative battery terminal first to prevent damage to the ECM.

 
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