P2187 - with normal fuel trims???

Hi Guys

Joined today cause I have an issue I want to clear up and cause I work on my car myself. A little technically inclined.

So my car gives P2187 - System Idle Bank 1 lean. Did some research. No apparent vacuum leak to be present.

My question is, how does this fault gets activated? I am presuming LTFT+STFT exceeds a certain value during idle which triggers this.

Part I don't understand, when checking the fuel trims with my Torque App, the LTFT is never higher than 3.1% and STFT seldom passes 10%.

After reset, Fault appears around driving FOR ABOUT 100km's.

TIA

Sorry Guys

Forgot to ad it's an Opel Corsa OPC (1.6 turbo) 2012 model.

Anyone?

Question is what logic does the PCM use to activate this fault?

Being an Opel, I'm not gonna have access to service information to look up the actual code set criteria. But I think you're right on with your thinking that the trims will have to exceed a combined value for a set amount of time to set that specific code. 25% or higher is a good bet.

Do you still have access to the Freeze Frame data associated with that code? That'd be the first step to understanding when this code sets. If there's any way you can post that data here, that'd be awesome.

The US didn't get the 1.6L turbo, unfortunately. BUT, it appears very similar to the 1.8L engine we see in the Sonic and Cruze. If that's the case, then there's possibilities for internal vacuum leaks from the PCV system that won't show up with normal testing. First confirm when the code sets, and we can go from there.

chee_dee wrote: when checking the fuel trims with my Torque App, the LTFT is never higher than 3.1% and STFT seldom passes 10%.

After reset, Fault appears around driving FOR ABOUT 100km's.

TIA

Keeping in mind that that is when it isn't faulting - so as mentioned freeze frame data may show very different readings when the fault code is set.

Hi guys, thank so much for the responses. I only have the torque app to work with, but I have an idea when and how the fault will appear each time, will try and get freeze frame data of it.

I have found the problem. The boost pipe just below the turbo had a stripped clamp. So it looked and felt tight but leaked under boost.

I did not reset the error after fault was fixed to see if it will go away, and it did after about 100kms of driving.

LTFT now sitting at -1.6 to -0.8 constantly. As opposed to +2.3 to +3.1 with the leak present.

I would thing the PCM will look at a raised fuel trim from around +2.5 and after a certain time of staying there, this fault gets locked.

Thanks for the assistance guys.

Congrats! What led you to start checking out the hot side of the intake?

LTFT now sitting at -1.6 to -0.8 constantly. As opposed to +2.3 to +3.1 with the leak present.

See, now I'm kinda confused. :silly: The code indicates a lean at idle, but you'd think the stripped clamp would cause an issue under boost. Plus, those numbers are reasonable, yet obviously the PCM is happy now.

Wondering if those long term numbers are weighted differently than I'm used to. As in, 1% on the long term equals 10% in short term? Just speculating.

Problem is still present. I am starting to think that it does not look at the fueltrims to activate the error. Since I started looking for this problem the LTFT has been +3% at a point and after changes (boost leak and also removing cone filter), it now stays at -1.6%.
I am starting to wonder if it does not look at the RPM at idle... The EML light always goes on when at idle. Never when driving. Sometimes it goes on when coming to a stop street after a 30 min trip, and sometimes on start up when the car is NOT cold.
I only have the Torque App to play with currently so as far as I know I cannot do get freeze frame data. Unless I am recording the values when the fault activates.
Think I need to start looking at the rpm values. Seems to be around 750-790 rpm when at operating temperature.