when the servo opens the htev all the way it come to a stop and wont turn any more, the computer know where the servo is suppose to stop. if you disconnect the servo from the htev it will turn more than its suppose to and the bikes puter will know this and throw a code.

 

I would think the ecu would have a preset amount to turn the servo and therefore the valve should be in the correct position. What you're saying is the servo/ecu sense the valve at half or full opening and stop the servo at that point, right. I'm thinking HASS. I'll be curious to see what happens on Kid's because unless there was some sort of microswitch on the valve how would it sense the opening or closing events?? Good to hear yours is running great KID!

 

Thanks! It's nice and like I said, it's got a nifty growl to it!

Here's the deal with the MIL code #35...

It will trip IF:

1. Your HETV does not move freely, and/or;

2. Your servo motor itself is bad, and/or;

#2 is likely the result of #1. SO, if you're checking the valve itself, you should also check that the servo motor operates normally (procedure is in the manual).

My problem was #2 and never #1. My valve moved freely, but the pulley system on the servo had become damaged at some point with frayed wires, not allowing it to function, and resulting in stripped gears - so while we had the same result - his was caused by carbon and mine was human error (prevous owner, obviously).

So, if you're tripping the code after resetting it, it's more than likely because of the servo motor itself being bad, like I said, you can test it using procedures inthe manual. Mine is bad so I will trip the MIL everytime because that little nothingpart is just going to have to wait, lol.

I wonder if I can simply short the lead to the servo motor and convince the ECU everything is normal? Anyone think that would work?

As a side note,a faultyvalve in the airbox could cause the trip as well but I think we've all established, at least in our cases, that's not the problem.

 

Kinda unclear there...

I guess what I meant by that was,

If the valve can and will move freely with no cables attatched to it (not stuck), it will have some room to travel back and forth (because of the design it has to travel back and forth) and with the exhaust being shoved out of it, it will not stay in place.

I don't know if anyone misunderstood that or not.

 

Did you end up welding it?? Here's my thing. I want to do the mod. I don't want a malfuntion light. If pulling the cables and tacking the sucker open works, said and done. Here's the prob, does the ecu control the stopping point of the servo meaning if the cables are gone the ecu will not know the difference, no code. Or does theservo sense the valve hitting the stopping point meaning no cables the servo will continue to look for a stopping point and eventually set as code. Myself and Pitbike established it to be the ecu, and Bravehart said the valve stops it. ??? Mine functions normally now, just looking for that extra little. Anyone with a Hass elim should be able to answer this as the install on it removes the whole assembly.

 

No, if your servo motor is working properly it will continue to do so... it just won't have any cables in place to affect anything.

Lucky you, [:@]bastard...

Do it and let us know how it goes.

In your case you won't have to do anything other than remove the 5 10mm bolts on the sidestand-side of the HTEV housing. There will be another 10mm bolt under that cover. That bolt is under load of a spring so just be aware when you're pulling it off. Once you got it off, pull the valve out and reinsert it with the holes facing 9o'clock, 6o'clock and 3o'clock. The closed part of the valve goes facing up (12o'clock). Tack weld that bitch in place and put everything back together!

 

THX for the info, I'll let you know how it turns out.

 

just an update on mine....the bike is running VERY, VERY good...better than it has for a while and sounds better too. The last thing that is a minor irritant is the red MIL light because of the servo. It will be there until I find a used servo to replace it with.

 

Here is some technical info on how the servo motor operates:

Servomotors, in general, are typically comprised of a DC motor, gearbox (usually planetary), and at least a position sensor and some even include a rotational velocity sensor.

The servomotors used in motorcycle applications have a DC motor, planetary gearbox and a potentiometer (rotary variable resistor) as a rotational position sensor.

The ECU sends current to the DC motor. The motor turns, which rotates the planetary gears, which via cables turns the valve(s). At the same time the position sensor (potentiometer) inside the servomotor assembly also turns. A position signal comes from the position sensor, which of course changes to reflect any changes in the valve position.

The current sent to the motor is known as the ‘command’. The signal coming from the position sensor is called ‘feedback’.

During R&D engine development a ‘map’ is created, based upon engine variables, that identifies the ideal position for the servomotor. During engine operation, the ECU ‘looks’ at the map and compares it to the feedback (valve position) signal. If the two are the same, then it does ‘nothing’ (sends no current to the motor) because the valve is where it is supposed to be. If the feedback signal is different than what the map specifies, the ECU ‘looks’ at the difference between the map and the feedback and sends a ‘command’ current to the motor to turn it in the right direction to get it to where it needs to be. As the motor gets closer and closer to where it is supposed to be (because the ECU ‘knows’ this from constantly monitoring and comparing the feedback signal) the current signal (command) gets smaller and smaller, thus decelerating the motor so it just ‘glides’ into position.

Keep in mind, what I have just described happens on a very fast scale, so what I describe as ‘gliding’ looks to be an instantaneous smooth transition of valve positions.

 

Great info!