Car in closed loop mode at low throttle

[x6gas]

Just been looking at freescan on a warm-up cycle on my S4.

I had the battery disconnected and so the ECU was just reset and in learning mode.

I was a bit surprise that fairly early into the warm up, the car goes into closed loop mode (at least I assume that's what it means - the closed loop field goes to one) and stays there.

I thought that closed loop mode was only for throttle openings above 90%? Anyone have any ideas?

For what it's worth - freescan hasn't shown much up. The baro pressure is a little high at 0.87 and the MAP is a little high - I'm guessing that the MAP is down to a small leak somewhere on the inlet system.

[Dermot]

Closed loop is triggered when you have positive feedback from the O2 sensor. It starts when the O2 sensor is up to temp about 5 min after a cold start.

Open loop is when the ecu just pours in fuel blindly, only happens when a number of conditions are met eg. 95% TPS + high boost etc...

baro = 0.87 means it was a fairly nice day, totally in spec.

You are welcome to email me a log file.

Dermot

[Bibs]

Open loop is when the ecu just pours in fuel blindly, only happens  when a number of conditions are met eg. 95% TPS + high boost etc...

aka fun

[Paula&Marcus]

Just been looking at freescan on a warm-up cycle on my S4.

I had the battery disconnected and so the ECU was just reset and in learning mode.

I was a bit surprise that fairly early into the warm up, the car goes into closed loop mode (at least I assume that's what it means - the closed loop field goes to one) and stays there.

I thought that closed loop mode was only for throttle openings above 90%?  Anyone have any ideas?

For what it's worth - freescan hasn't shown much up.  The baro pressure is a little high at 0.87 and the MAP is a little high - I'm guessing that the MAP is down to a small leak somewhere on the inlet system.

<{POST_SNAPBACK}>

Ian,

Its just the other way round !

Car is almost all the time in closed loop, only when TPS is greater than 96% it will switch to open loop and does the fuelling via fixed tables.

Marcus

www.PUKesprit.de