[2ndAmend]

I always baby my cars and never run hard until they are fully warmed up. But even though the car is warmed, it seems to go open loop if I shut it off and go inside a store for 10min. With the M6, the obvious clue that it is in open loop is that the throttle does not let up immediately when I am off the pedal, when I push the clutch the engine rev’s due to the no-load even though I am off the pedal. To avoid this I need to let off the pedal a second or two before pushing the clutch during open loop.

QUESTION:

Is there any objective way to know when the car goes closed loop? Is there some display somewhere that will tell me?

Thanks!

 

[akras]

I just go by oil temperature: I don't exceed 2,000 RPM until it's 140F (it's a 6MT), and consider it fully warmed up and ready to be pushed when the oil reaches 180F.

Why do you care if it runs open loop if the mechanicals are warm enough? The computer makes the decision to go open loop based on many factors (including, likely, the temperature/efficiency of the catalytic converters, which get cold when you stop for a few minutes), but why should you be concerned with that?

 

[baabootoo]

I was always under the impression it was like 160F? Not at thermostat opening, but warm enough where you no longer need extra fuel enrichment. I would guess that you could find it out by researching it. Have you tried monitoring the AF ratios at startup?

 

[2ndAmend]

Have you tried monitoring the AF ratios at startup?

Good idea, I will start watching that.

 

[2ndAmend]

Why do you care if it runs open loop if the mechanicals are warm enough?

OCD. It makes me feel better to know it is ready when I lean on it. Also, during OL it might not be giving optimum performance. I try to take good care of my toys.

When I am concerned I watch the oil also, I like to see 195. OCD again.

 

[baabootoo]

So can we assu 😁 me that you have your oil analyzed at 500 mile intervals too????????????

 

[Rockster]

From my experience with other cars the ECM goes closed loop concurrent with the drop of the cold idle RPMs to hot idle RPMs.

If the engine controller is in closed loop mode it can return to open loop mode if you shut off the engine for a while. The sensors/converters cool down and upon restart these have to warm back up to their operating temperature. If the engine is not started from a dead cold state this doesn't take but a few moments.

The only way I know of how to know the ECM has switched from open loop mode to closed loop mode is to connect an OBD2 scan tool the car's OBD2 port and bring up the OBD2 mode reading.

It will tell you the mode the ECM is in:

Value	Description
0​	The motor is off
1​	Open loop due to insufficient engine temperature
2​	Closed loop, using oxygen sensor feedback to determine fuel mix
4​	Open loop due to engine load OR fuel cut due to deceleration
8​	Open loop due to system failure
16​	Closed loop, using at least one oxygen sensor but there is a fault in the feedback system

I do not recall ever bothering to observe my Hellcat and its ECM modes. I just relied on the fact the fast cold idle RPMs dropped as a sign the ECM had switched to closed loop operation. What I really paid more attention to was oil temperature to know when the oil and thus engine was at a hot enough operating temperature.

 

[2ndAmend]

So can we assu 😁 me that you have your oil analyzed at 500 mile intervals too????????????

LOL! Hell no! That costs $! I'm a cheap OCD! (Never less than 750. Kidding!)

 

[2ndAmend]

If the engine is not started from a dead cold state this doesn't take but a few moments.

Thanks Rock, I expected your post!

Moments in my case is a minute or so. Every month I drive an hour home on the hwy, fuel up then drive 3mi home. The car is always open loop coming out of the gas station, which is a bit annoying because it is holding the throttle for an extra second after I let off the pedal like I described in the initial post. No big deal, just a little embarrassing if I forget to let off the pedal early and the engine revs when I push the clutch in. I can't imagine what the programmer was trying to accomplish by doing this.

 

[Rockster]

Thanks Rock, I expected your post!

Moments in my case is a minute or so. Every month I drive an hour home on the hwy, fuel up then drive 3mi home. The car is always open loop coming out of the gas station, which is a bit annoying because it is holding the throttle for an extra second after I let off the pedal like I described in the initial post. No big deal, just a little embarrassing if I forget to let off the pedal early and the engine revs when I push the clutch in. I can't imagine what the programmer was trying to accomplish by doing this.

After driving an hour on the highway the taking a few minutes to gas up the car I would not expect it to take that long for the engine controller upon engine restart to switch back to closed loop mode. The sensors and converters are hot but course lose heat the moment the engine is shut off. But the sensors and converters are not out in the air but are part of the exhaust system all of which holds heat. IOWs there is a lot of very hot metal around the sensors and converters. My point is I would not expect the sensors and converters to cool that much in the few minutes it takes to fuel the car.

That holding the throttle may not be that reliable a sign the ECM is in open loop mode. My Scat Pack (6-speed) throttle is "slow" to close. This is the engine controller doing this to reduce emissions. Keeping the throttle open keeps air flow through the intake and this works to reduce emissions vs just letting the throttle close to its idle opening.

 

[2ndAmend]

That holding the throttle may not be that reliable a sign the ECM is in open loop mode.

It only does it after it is turned off a few min, every time I gas up. I was in a store today for 10 min and did the same thing. And I usually forget and get the stupid rev on the shift. Only lasts a minute or so, just enough to embarrass as I leave!

 

[2ndAmend]

Have you tried monitoring the AF ratios at startup?

Just started watching today after being in the store for 10 min, got the throttle hold thing, idle A/F=12.7. 5 min later at home it was 13.7. I'm going to watch this.