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  #1  
Old 10-26-2010, 11:55 AM
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Re-learn procedure

Has anyone tried this relearn procedure after a major change:

* Set parking brake, start engine in "P" or "N" position.
Warm-up vehicle to normal operating temperature or until
cooling fan cycles.
* Allow vehicle to idle for one minute in "N" position. Select
"D" and allow engine to idle for one minute.
* Accelerate at normal throttle position (20-50%) until vehicle
shifts into top gear.
* Cruise at light to medium throttle.
* Decelerate to a stop, allowing vehicle to downshift, and use
brakes normally.
* Process may be repeated as necessary.

If so, does anyone know if the car has to be started cold or can it be started warm in step 1?
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Tony

1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads
2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil
2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil
1992 Red Ferrari 348 ts, 82,XXX, Redline everything
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  #2  
Old 10-26-2010, 12:48 PM
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Re: Re-learn procedure

Quote:
Originally Posted by Huskymaniac View Post
Has anyone tried this relearn procedure after a major change:

* Set parking brake, start engine in "P" or "N" position.
Warm-up vehicle to normal operating temperature or until
cooling fan cycles.
* Allow vehicle to idle for one minute in "N" position. Select
"D" and allow engine to idle for one minute.
* Accelerate at normal throttle position (20-50%) until vehicle
shifts into top gear.
* Cruise at light to medium throttle.
* Decelerate to a stop, allowing vehicle to downshift, and use
brakes normally.
* Process may be repeated as necessary.

If so, does anyone know if the car has to be started cold or can it be started warm in step 1?
If you have to relearn the maps, then it means your battery has been disconnected for at least an hour.... which is enough to cool the car back into open loop. The entire relearn process is done in closed loop when the car is warm, and the O2 sensors are hot enough to start detecting your exhaust oxygen.

This procedure is kind of useless, since most everything they ask you to do is experienced in regular driving anyways.
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  #3  
Old 10-26-2010, 01:39 PM
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Re: Re-learn procedure

Quote:
Originally Posted by SoCal LS-L View Post
If you have to relearn the maps, then it means your battery has been disconnected for at least an hour.... which is enough to cool the car back into open loop. The entire relearn process is done in closed loop when the car is warm, and the O2 sensors are hot enough to start detecting your exhaust oxygen.

This procedure is kind of useless, since most everything they ask you to do is experienced in regular driving anyways.
My impression is that this sequence will immediately reset the closed loop parameters and provide a decent starting point for them instead of waiting the 30-40 drive cycles it normally takes for the closed loop parameters to re-adjust either from current erroneous values (if you just replaced an O2 sensor, for example) or from default values (if you disconnected the battery).
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Tony

1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads
2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil
2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil
1992 Red Ferrari 348 ts, 82,XXX, Redline everything
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  #4  
Old 10-26-2010, 03:40 PM
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Re: Re-learn procedure

Quote:
Originally Posted by Huskymaniac View Post
My impression is that this sequence will immediately reset the closed loop parameters and provide a decent starting point for them instead of waiting the 30-40 drive cycles it normally takes for the closed loop parameters to re-adjust either from current erroneous values (if you just replaced an O2 sensor, for example) or from default values (if you disconnected the battery).


What resets the parameters is leaving the battery disconnected.... and they already have decent starting points.... default from factory.

The procedure outlined is so the ECU can relearn more efficient fuel and timing maps during

a) Idle, no load
b) Idle, TC load in gear
c) Normal acceleration
b) Normal sustained cruise

So my point is, this is experienced in normal everyday driving. LOOK at the instructions closely... "Process may be repeated as necessary".

So if you want, you can be the guy doing laps around his neighborhood trying to efficientize his car, OR you can just drive through town on errands when you need to, and it will be almost exactly the same and easier for you. You may lose $3 in fuel mileage, tops... I promise.
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New?? Find the downloadable SVX Online Service Manual Here
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  #5  
Old 11-20-2010, 08:57 PM
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Re: Re-learn procedure

So it has been about a month since I replaced the faulty O2 sensor and my long term fuel trim numbers are still high for that bank. I got a highway cruise value of about +14%. The other bank is petty close to zero. I ran a can of seafoam through the fuel system just in case it was a clogged injector but that didn't help. I am thinking of going to something more powerful like Redline SI-1 or the concentrated Chevron Techron. Any other ideas why the fuel trim would still be high? Maybe I should disconnect the battery for a half hour and just reset the whole ECU?
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Tony

1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads
2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil
2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil
1992 Red Ferrari 348 ts, 82,XXX, Redline everything
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  #6  
Old 11-21-2010, 03:16 PM
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Re: Re-learn procedure

Quote:
Originally Posted by Huskymaniac View Post
Maybe I should disconnect the battery for a half hour and just reset the whole ECU?
Would this be the first time you did it since replacing the O2?
__________________
Chris

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New?? Find the downloadable SVX Online Service Manual Here
RECOMMENDED READING for newer SVX owners Here some cool info if not fully accurate.
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  #7  
Old 11-21-2010, 04:42 PM
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Re: Re-learn procedure

Quote:
Originally Posted by SoCal LS-L View Post
Would this be the first time you did it since replacing the O2?
Yes but I guess I assumed that the ECU would have re-adjusted to the new O2 sensor by now. Bad assumption?
__________________
Tony

1996 Polo Green Subaru SVX LSi, 168,XXX miles, Redline D4 ATF, Redline 75W90 gear oil, K&N HP-4001 Oil Filter, Mobil 1 5W50 FS (3qt) and 5W30 High Mileage (4qt) Oil Blend, Motul RBF600 Brake Fluid, AC Delco A975C Air Filter, NGK BKR6EIX-11 plugs, Centric Rotors, Power Stop Evolution Carbon Fiber Ceramic Brake Pads
2005 Gray Acura RL, 165,XXX miles, Redline D4 ATF with Lubegard Platinum Protectant, Mobil 1 5W20 High Mileage Extended Performance Oil
2009 Red Toyota Venza, 123,XXX, Mobil 1 5W30 High Mileage Oil
1992 Red Ferrari 348 ts, 82,XXX, Redline everything
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