Acura TSX Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
68 Posts
Discussion Starter · #1 · (Edited)
Hey guys so I just replaced my throttle body with a newer used unit as my car was not holding rpms at idle and it kept dipping when I came to a stop. This was exacerbated with the AC on, so I at first thought my AC was overcharged. However I started noticing this symptom without the AC running. So I suspected that it was the TB as we don't have an IAC valve in the air box but rather a sensor in the TB.

So I just swapped it for a TB out of a TSX with a 109k miles. And when I started the car the VSA and Check Emissions light came on within the first few seconds and the car was idling high. Wondering where to go from here. I'm reading that the idle relearn procedure is necessary when replacing the TB. I installed this part with the battery disconnected.

Is it normal for the VSA and Emissions system lights to be on while the idle relearn is taking place? I was somewhat startled by that and shut it off not long after.

I did spill some coolant below the TB when i removed the hoses. So I'm letting it sit with the negative battery cable off and the hood up to let everything dry before trying again.

Hooked up my OBD II gauge. Got 1 code for P2176, Throttle Actuator Control System Idle Position Not Learned.
 

·
Registered
Joined
·
68 Posts
Discussion Starter · #2 ·
I swapped the old throttle body back on and the VSA and check emissions light came off. So I suppose those lights will automatically come on when you put on a new throttle body?
 

·
Registered
Joined
·
256 Posts
Coolant will not evaporate, at least not the glycol part.. And it will cause electrical gremlins. You need to hose it off good, and make sure any connectors which have gotten coolant in them are clean and dry.

Since you got the not learned code maybe it just takes time. I suppose you could try driving it around and see what happens. I'd look in my shop manual but I'm not at home right now.
 

·
Registered
Joined
·
68 Posts
Discussion Starter · #4 ·
Coolant will not evaporate, at least not the glycol part.. And it will cause electrical gremlins. You need to hose it off good, and make sure any connectors which have gotten coolant in them are clean and dry.

Since you got the not learned code maybe it just takes time. I suppose you could try driving it around and see what happens. I'd look in my shop manual but I'm not at home right now.
Thanks for the reply. Im thinking that leaked coolant isn't the problem at this point. After putting the old TB back on the VSA/Check Emmissions light went off.

When I put the new TB the car wasn't drivable because giving it gas was making the RPM's go up and down.

So with the old part back on I appear to be back to my original problem. I've included a video I took of it from a month ago. The problem appears to be getting progressively worse. I first thought this was happening only with the AC on(which i just replaced the compressor and other components). However it started doing this with the AC completely off, thus I suspected the TB. But is there anything else that might cause this? This "dipping" occurs in park and at idle when coming to a stop. There are no engine codes. I know that it is normal for some rpm's to dip and come back up as you turn on accessories, but this is not that and visibly not normal.

 

·
Registered
Joined
·
29 Posts
I had the vsa light problem with the check engine light it turn out to be the throttle positioning sensor the one on the passenger side by the strut tower with plastic cover, I replaced it with one from pick and pull because a new one was way to much and I wanted to make sure that was the problem. You can find them on pretty much any accord of the same year just make sure you get the right plug.
Motor vehicle Shipping box Automotive lighting Gas Machine
 

·
Registered
Joined
·
68 Posts
Discussion Starter · #7 ·
I had the vsa light problem with the check engine light it turn out to be the throttle positioning sensor the one on the passenger side by the strut tower with plastic cover, I replaced it with one from pick and pull because a new one was way to much and I wanted to make sure that was the problem. You can find them on pretty much any accord of the same year just make sure you get the right plug. View attachment 49608
Thanks for your reply man. Unfortunately the VSA and Check engine light only appeared when I swapped the throttle body. When I put my old one back on those lights went away. What I don't know is if that is a standard thing to happen when swapping TB's.

The part you are referencing is the Accelerator Position Sensor. I haven't noticed any issues accelerating. My problem is a very odd and worsening dip in my RPM's while idling and coming to a stop. I'm not sure the APP would cause this. I was suspecting that it was the TPS sensor in the throttle body since we don't have IAC valves in the TSX.
 
1 - 8 of 8 Posts
Top