When does the car enter closed loop mode

[aceventura]

Purely out of interest, does anyone know what tells the ECU to enter closed loop mode?

If it is the CTS, at what temperature does this happen?

[hako]

I checked some links but came up with some very complicated answers and definitions - here's the best one I could find:
Closed Loop Parameters

[delcowizzid]

starts from about 40 degrees coolant temp on most tunes some are higher.plus it depends on load on the engine all cruise areas are in closed loop up till close to full throttle.if need be i can be more specific.

[aceventura]

Thanks guys - very informative.

[aceventura]

Ok, now a have a real question associated with this.

I have been getting an intermittent Code 13, so I got an ALDL cable the other day and I was using EFILIVE to look at the engine parameters. I have two problems that I think are related: The ready status of the RH O2 sensor keeps changing and the fuel mode never become closed within the half an hour of driving

The LH O2 sensor becomes ready quite quickly, but the RH sensor is a problem. The sensors are fairly new (replaced this time last year, and done ~ 10000 km). The RH sensor constantly reads around 600 mV only oscillating small amounts, compared to the LH side, which oscillated with a large amplitude. I guess this is the old earthing problem on the RH O2 sensor in the VS.

I have attached screen shots from EFILIVE. In the dashboard mode the RH O2 is ready, but the status changed about three seconds after the screen shot was taken.

My questions:

Is there a time delay (in the order of minutes) that it takes to enter closed loop mode after the O2 sensors become ready?

Since putting a multimeter across the O2 sensor ruins them, does the leaking current also ruin them? Or is the leakage small enough that if I cut the pink wire (or fix the earth at the ecu), the sensor should still be ok?

Thanks for any help.

[aceventura]

Ok, I cut the heater wire on the RH O2 sensor. It now takes about 1 min longer to become ready (compared to the LHS sensor), but seems to be operating properly when hot (see attached image). So it appears the leaking current didn't damage the sensor. If I get keen, I will do the proper fix at the ecu, and solder the heater wire on the sensor back together.

However, according to EFILIVE, the car never enters closed loop mode - Is this a problem with EFILIVE, or the car??? Has anyone got any experience here?

[undar8ed1]

Ok, I cut the heater wire on the RH O2 sensor. It now takes about 1 min longer to become ready (compared to the LHS sensor), but seems to be operating properly when hot (see attached image). So it appears the leaking current didn't damage the sensor. If I get keen, I will do the proper fix at the ecu, and solder the heater wire on the sensor back together.

However, according to EFILIVE, the car never enters closed loop mode - Is this a problem with EFILIVE, or the car??? Has anyone got any experience here?

EFI live eval gave me the run around for months telling me that the TPS O2 sensor and CTS was faulty but no matter what I did I could not remove it, took it holden and they diagnosed it with the tech 1 and all that came up was air temp sensor changed that and the DTC light never came back.

[aceventura]

Yeah, I saw this too, but I think the problem with the error codes is related to the fact it is an evaluation version. I checked my codes with a paper clip before I used EFILIVE, so I knew it was lying.

All the other status flags appear to work fine, but the fuel mode never seems to move from open.

[aceventura]

I have done a little reading and from what I can tell, the signal from the O2 sensors only oscillates because the ecu is constantly switching between lean and rich mixtures once the car enters closed loop mode. So if my O2 sensor readings are oscillating, then the car must be in closed loop mode. Can anyone confirm this?

[alex2_s]

Browser Warning

read this regarding lean cruise feature etc

edit- browser warning???

[delcowizzid]

yes they will only swing when in closed loop mode ide say the flag isnt setting for some reason maybe due to being eval

[immortality]

funny things is, the LH O2 sensor does exactly that on my VS. bloody weird that is.

i'd take that article with a grain of salt, there are a few errors in it

[aceventura]

Thanks for your help everyone. I think most of it makes sense now.

Searching through the flags, it seems that EFILIVE has two different flags listed for fuel mode. I wonder whether the "fuel mode" I was looking at was actually the "lean cruise" mentioned above? Anyway next time I go for a drive I'll check the other one. However, based on what I have been reading, and delco's comments, I am no longer concerned about this as I am in no doubt that the car is entering closed loop mode.

[aceventura]

Ok, got the fuel mode sorted with EFI live - you tuning guys probably already know, but I'll put it in for future reference anyway.

The actual open-, closed-loop mode is FLAG 35, bit 6. I changed the dashboard to show this status flag, and it worked perfectly.

There is another parameter that EFILIVE claims is the fuel mode at FLAG 32, bit 2 (the status flag I was using). I am not sure what this is, but as alex2_s mentioned, it could be the lean cruise mode.

Cutting the pink wire appears to have cut my city fuel economy from ~15L/100km, down to ~12L/100km. Highway fuel economy hasn't changed much. I am still keen to do the proper fix on this though.

[immortality]

ahh, just found your thread.

in the first log you posted you can see that the O2's are swinging but in the lower part of the graph about 600mv peak. in the 2nd pic in the later post it's about where mine are around the 900mv at it's peak.

now that i re-wired mne both are the same so that was the main aim for starters. now i gotta see how it goes