P0638 - Error Code | Rocket 3 Roadster 2018

buddazero

.060 Over
Joined
May 19, 2018
Messages
150
Location
New York City
Ride
Triumph Rocket 3 Roadster 2018
Hey,

So, I'm not an expert but I do have Tune ECU to check in on stuff. My Rocket Setup is:

The moment it happened, I started the bike and noticed that the number on the gas meter (the one that tries to guess how many miles you have left) was a lot higher since I've last turned it on. After riding less than a mile the Engine Light came on. Few hours later, I used Tune ECU on my phone and saw the error code P0638.

What I did next was deleted the error code, and Ran a 2nd Throttle Test, I heard the engine do it's thing, and it said Test Complete, and it didn't display anything. I then turned on the bike, and the Engine light didn't come on. Does that mean the test did its thing and it's basically saying "everything is working fine?"

It just so happens I'm going in Friday to service my bike. If it does happen again, hopefully they can fix it, I'll still tell them what happened even if the engine light doesn't come on.

How can I on my own resolve the issue, can I access the 2nd Throttle underneath the Bear Claw? The Ram Air Kit is most likely above it as well, are there instructions to take it off?

Thank you for reading,

Best,

Budda
 
As i recalect a friends bike had that code and i cleared it and it never came back. Must hav have been a sticky 2nd tps.
 
TURBO200R4 said:
As i recalect a friends bike had that code and i cleared it and it never came back. Must hav have been a sticky 2nd tps.
Click to expand...

What do you mean by sticky?

Also, I rode the bike all day today...and the engine light never came back on. Maybe it was just closed incident that happened for like a second?
 
Seems to me that this error can come from when resistance to the secondaries moving occurs, detected possibly via increased current draw by the stepper motor which makes ECU throw the code.
Can you pop off the air filter and see if the throttle butterflies move smoothly and freely?

Perhaps your issue was the same as mine, sporadically coming and going until this adjustment was made.
Or maybe some lube in around the linkages & springs between throttles will sort it.

 

I have the Ram Air Filter Kit, I've been comfortable taking my bike part, I did the whole exhaust header system myself, but have not yet taken off the Ram Air, I need to find some documentation on how to do so, or maybe I'm remembering it wrong, I do think the Ram Air filter kit is right above it.

Either way, I'm getting it serviced and I told them before hand, and they mentioned that they were going to check everything, BUT I would like to do it myself in the future. I keep learning this about my bike it's so funny
 
my advice is to leave that 2nd throttle motor/actuator alone and not touch it!
if it is screwed up u have to replace the throttle body assy.
 
TURBO200R4 said:
my advice is to leave that 2nd throttle motor/actuator alone and not touch it!
if it is screwed up u have to replace the throttle body assy.
Click to expand...
Right now I've been riding and the error hasn't popped up-but Like I said, I will mention it to the dealership. They have a Rocket so I trust them, they've been good to me so far.

If it is messed up they'll know what to do.
 
buddazero said:
Right now I've been riding and the error hasn't popped up-but Like I said, I will mention it to the dealership. They have a Rocket so I trust them, they've been good to me so far.

If it is messed up they'll know what to do.
Click to expand...

yes install new throttle bodies
 
TURBO200R4 said:
my advice is to leave that 2nd throttle motor/actuator alone and not touch it!
if it is screwed up u have to replace the throttle body assy.
Click to expand...

You can't really go wrong with it, the 2 bolts only allow a very small degree of rotational play.
The stepper is built into the throttles pretty good.
All you're doing is centering it so it isn't causing a bind on the buttlerly vane.
 
The dealership took a look when it was getting serviced. The throttle body was physically off. He was surprised that the bike didn't stall on me. That was probably when the engine light came on.

Anyways, all is well!
 
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