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Old 03-05-2005, 12:38 PM   #1
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Default Exactly what triggers closed loop status?

I scaned my car and according to my scan tool, when my coolant reaches 195 degrees, on my stock thermostat, the car still doesnt enter closed loop. Could there be another problem
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Old 03-05-2005, 04:13 PM   #2
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I sure thought it was coolant temp.... that'* weird. You o2 isn't knocked loose right? if that'* unplugged, it won't go into closed loop.
You mightwant to try and replace your coolant temperature sensor?
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Old 03-05-2005, 04:16 PM   #3
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i got it let me write it up for ya
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Old 03-05-2005, 04:24 PM   #4
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Loop status- Tech 1 dispays open or closed loop

Closed loop displayed indicates that the PCM is controlling fuel delivery according to the O2 sensor voltage. In open loop the PCM ignores the O2 sensor voltage and bases the amount of fuel to be delivered on the TP sensor, engine coolant teperature, and MAF sensor imputs only.

Closed loop operation should begin when the the O2 sensor becomes active, engine coolant temperature exceeds 50*C (122*F) for more than 30 seconds and the PCM has seen 1200 RPM or greater for 10 seconds.

At extremely high ambient temperatures or when towing a trailer it is possible for the system to remain in open loop operation to control catalyic converter temperatures
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Old 03-05-2005, 04:29 PM   #5
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Quote:
Originally Posted by 95naSTA
You mightwant to try and replace your coolant temperature sensor?
That'* what came to my mind.



Check its resistance at varying temps (hot/cold water?)?



[/guess]
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Old 03-06-2005, 01:45 AM   #6
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I'm thinkin O2 sensor.
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Old 03-06-2005, 10:41 AM   #7
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I'm thinking MAF sensor based on his post in Forced Induction. Are you spraying nitrous on the MAF?
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Old 03-06-2005, 11:35 AM   #8
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I dont even have the kit on. I think my coolant temp sensor works fine, when i scan it, it doesnt seem to be acting abnormaly, it starts out at a low temperature and works its way up with the gauge and all. and my O2 sensor voltage is normal too.
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Old 03-06-2005, 03:21 PM   #9
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IF it has to go into open loop status before it starts to read the O2 sensor then how can the O2 sensor being bad prevent it from going into closed loop. I know the ecm knows its there because when i scan it i can see the voltage bounce around. And the scan tool detects temps by the volatage coming out of the coolant temp sensor just like the Ecm does right? so if the scan tool can recognise a change in voltage, then the ecm can too right?
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Old 03-06-2005, 10:26 PM   #10
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How can i find out if there is a tps or maf sensor problem. What should the voltage be on each of those and what is there to look at?
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