Resolved: CEL for Butterfly valves - / driving pedal position - Sensor A
 

Hi everyone. I was hoping to get some help from the more mechanically inclined. I am US military in Germany and my 8 threw a CEL and the TCS/DSC light stays one. This happens when I first try and start the car, even if I have just turned it off. When this happens my RPMs won't go over 2000 either. I took it to a German Mazda dealership and they read the code (for 20 euros) and it came back with:

Beschreibung - P2109
Drosselklappen - / Fahrpedalstellungs - Sensor A: Leerlaufstellung: Funktion

This translates to: Description - P2109
Butterfly valves - / driving pedal position - Sensor A: neutral: Function

I looked up the P2109 and it came back as the TP sensor minimum stop range/performance problem. :banghead:


EDIT: Ok - I originally thought the "TP" was tire pressure but it is Throttle Position.. Now this is making sense...


Needless to say - I'm a bit confused. They told me that the part I circled in the picture either needs to be 'cleaned' or replaced. When I first try to start the car, it faults, like I said. If I turn it off and then pop the hood, disconnect the electrical connection on the part circled in the picture - then plug it back in I can start the car and it will act normally (the CEL is still showing but the TCS/DSC light does out). The dealership also told me that they don't know if that part is the same for German Spec RX8s and for US Spec RX8s. Any help or guidance you could provide would be greatly appreciated. The German part, if it has to be replaced, will cost 460 euros. :Eyecrazy: If there are any good online parts vendors you could recommend that sells this part and will ship to an APO address using USPS Priority mail I would like to hear about them too. Thanks in advance for any help you all can provide. I am only 6 months from returning to the US, hopefully whatever solution works out will last long enough to get back to the US.

mkztg

That part pictured is the throttle body. It contains your butterfly valve that is electronically controlled. There is a small motor that opens and closed to allow more or less air into the engine.

If this valve isn't opening all the way, your engine will not get any more air to increase the power and thus limiting your RPMs....

So the dealership could be right, this could be the problem.


The part and connections you pictured look the same as my US spec. I can't be 100% sure though.

It will be easy to check+clean though using some hand tools and some throttle body cleaner (Seafoam "deep creep" if you have access to that)

That is where I would start. Disconnect the intake in front of the throttle body, turn the car to "on" (not engine running) and have someone verify that the throttle body is responding to the gas pedal position properly.

The other problem with this could be the sensor from the gas pedal is bad (which is the other code) That one I don't know too much about, you'll probably need a new pedal assembly.

Sorry I am not more help than that.

Vyndictive,

That was detailed information then I could get from the German mechanic. Its the whole language barrier. My car is US spec so the throttle body would be identical to yours. What the German dealership said was, they weren't sure if their part (Euro Spec) was identical to the US Spec one.

Thanks for at least cluing me in as to what that part is called. Like I said, there was a language barrier and the German mechanic couldn't think of the English word for the part.

I will check our automotive store here on post (very limited supply of anything - I have to special order my oil filters...) but I doubt they will have Seafoam.

Thanks giving me a place to start. :lol:

mkztg

Vyndictive just about nailed where to start.
I would inspect the TB flap (as pointed out above) and see if there is any build-up like oil sludge.
Then clean the flap itself.
You can open it fairly easily by hand, the stepper motor will give you very slight resistance.
While opening it, check to make sure the travel is consistent, meaning the motion doesn't skip/resist more at a certain position (like a belt skipping/slipping on a sprocket).

Jon,

Thanks for expounding on that. All the info I can get will help me when I work on this tomorrow. I appreciate your help.

This just proves what I have known all along - Rx8Club.com ROCKS...:)

-mkztg

I went to the auto craft shop (a place on post where you can work on your car - you can't work on your car at your house in Germany - environmental laws I think..) and they were all booked up so I won't get to try any of this until tomorrow.

I was talking to a friend here that is more mechanically inclined then I am and asked him if he thought this could be caused by bad gas.. Any thoughts from the experts here?

The only reason I ask is because my car was running just fine before I filled up with gas. About an hour after I got gas (car had been running most of that time) is when the problem first came up.

Is it feasible to think that I can clean out the throttle body and have this happen again because of the 'potentially bad' gas?

Also - if it is bad gas, should I replace my fuel filter too?

My car is old, its a 2004, but it only has 26,000 miles on it. I am the original owner - I don't know if that helps with trying to determine if the throttle body could actually be bad rather then just need a good cleaning.

Thanks again in advance for your help.

mkztg

Bad Gad: Modern gas is pretty stable... it can sit for a long time and still be fine. Long time I mean 6-12 months without any problems at all. I would eliminate bad gas.

Throttle Body failure IS possible, but there are a lot of '04s in here and it doesn't seem to be a common problem. Like Jon said, it could just be getting stuck at a certain level.

Still pull it off and clean it/inspect it.


Like I said before, it could be a malfunctioning gas pedal sensor (thats what the code would be) and it doesn't register anything past a touch of the gas pedal.

I think you can eliminate bad gas. My brother is in Germany also, stationed at Ramstien AFB (well, he's deployed currently.) And he has never had problems with leaving gas in his cat etc.
I think the EU has pretty tough standards on their gas... so I wouldn't even consider that a possibility.

Vyn,

Thanks for the reply. I am going to clean that out first thing tomorrow and hopefully that will fix it. If not I will have to take a look at the gas pedal sensor as well as the the throttle body itself. Hopefully it isn't too hard to narrow it down.

Again, thanks for your help. I hope your brother stays safe over in the desert. I got back in October from a 15 month trip - it was much too long.

mkztg

Had a similar code and 2k rev limit, it was the connector to another intake valve, the connector is a bitch to get at, it's under the airpump - exactly opposite the dipstick position (on the right side of the engine)

Good luck.

S

StealthTL,

Thanks for the feedback... I will check that too.. I don't suppose you have a picture of the connector? Like I keep saying, I am not mechanically inclined but visuals help me a lot. If not thats cool, I'm gonna check that out once I get the car up on a lift. Hopefully I can see what you are referring to.

Thanks again.

mkztg

No pics, but you can follow the wiring, it runs down behind the thermostat cover and to the grey, horizontal connector.

S

Thank you! :lol2:

Stealth,
I'm a little lost on what connection you are referring to.
Is this the harness:
Attachment 132504

Its not opposite to the dipstick, but its under the air pump.

^ your engine bay is gross. Are those bushes growing near your windshield wipers?

:)
Those are leaves from the fall season.
My car was parked under a tree.
That pic is from when my engine was flooded and I squirted the washer fluid into my maintenance ports.

No, it's down by the two lower intake 'nipples', between the engine and fender.

In that pic, it would be below the icky corroded air valve at top!

s

You are guys are so helpful.. I went out and took a picture.. Stealth - Is it the connector in the red box on the attached pic? You can ignore the circle, that is just my flashlight so I could see down in there before the flash on the camera went off..

If that is the connector, did you just disconnect and reconnect it? Did it need to be replaced to fix the similar problem you had?

Thanks.

mkztg

No that's not it, a bit more 'north-west' in the picture - try taking a shot of the lower nipples.....

I just gave it a couple of connects/disconnects to clean it up - code disappeared.

S

I think I found the nipples you are talking about -

Is this the connector? It is getting dark here in Germany so I had to take several pictures to even get these .. hopefully you can tell what I'm looking at..

If thats the connector - I can't reach it from the top. I'll have to try it from underneath when I get it on a lift tomorrow.

Let me know if that is the connector you were talking about.

Thanks!

mkztg

That's the one, in pic #2.

No guarantees, but that was MY solution.

S

Stealth,

Thank you very much.. I wasn't asking for a guarantee just some guidance. :lol2:

I really appreciate you Jon and Vyn helping me. I will try this first tomorrow and I think I will clean out the Throttle Body even if this fixes it. I will update the thread with what I know after working on it tomorrow.

Again - thanks to you all for your guidance.

mkztg

That's Jon... but close enough ;)

Sorry Jon... my fingers typed it wrong but I thought Jon in my head.. :)

:banghead:

Its all good. :beerchug:
Keep us updated on your findings.

worse case if you need the parts i have them and can ship to APO, i have a throttle body, gas pedal, and air pump wiring. lmk