open loop/closed loop
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Joined: Mar 2014
Posts: 34
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From: Danville, IN
open loop/closed loop
*2001 Dodge Dakota Sport 3.9L 42RE trans short bed Std. Cab*
What conditions must be met to make the system go into the closed loop mode? It seems like mine goes CL really quick and that's when it starts idling very rough. Also, just as it goes CL, the STFT for bank 1 and bank 2 goes to a value of -33.6% and stays there for about 30 seconds or so until the idle finally starts smoothing out. Then the values start to gradually change towards zero or more than zero.
During this time of rough idling, you can't drive the truck otherwise it will backfire through the intake/throttle body.
The Catalytic Converter Monitor should be run once per trip.
My scan tool shows it as either:
1) Never been run, or
2) Been run but never completed.
The EVAP System Monitor should be run once per trip.
My scan tool shows it as either:
1) Never been run, or
2) Been run but never completed.
The scan tool shows the same status for the CAT and EVAP every time I connect it and check the system. What could prevent these monitors from doing their jobs?
There are no DTC's.
What conditions must be met to make the system go into the closed loop mode? It seems like mine goes CL really quick and that's when it starts idling very rough. Also, just as it goes CL, the STFT for bank 1 and bank 2 goes to a value of -33.6% and stays there for about 30 seconds or so until the idle finally starts smoothing out. Then the values start to gradually change towards zero or more than zero.
During this time of rough idling, you can't drive the truck otherwise it will backfire through the intake/throttle body.
The Catalytic Converter Monitor should be run once per trip.
My scan tool shows it as either:
1) Never been run, or
2) Been run but never completed.
The EVAP System Monitor should be run once per trip.
My scan tool shows it as either:
1) Never been run, or
2) Been run but never completed.
The scan tool shows the same status for the CAT and EVAP every time I connect it and check the system. What could prevent these monitors from doing their jobs?
There are no DTC's.
Last edited by littlereddakota; Apr 30, 2014 at 07:12 PM. Reason: add more info
Section Moderator
Joined: Dec 2010
Posts: 4,858
Likes: 47
From: MA
Do you have the FSM? Chapter 25 pretty much explains what may be going on:
There are situations when the Task Manager does not run a test if another monitor is in progress. In these situations, the effects of another monitor running could result in an erroneous failure. If this conflict is present, the monitor is not run until the conflicting condition passes. Most likely the monitor will run later after the conflicting monitor has passed.
There's a lot more there too. What is your coolant temp showing? That is used to help determine open/closed loop.
There are situations when the Task Manager does not run a test if another monitor is in progress. In these situations, the effects of another monitor running could result in an erroneous failure. If this conflict is present, the monitor is not run until the conflicting condition passes. Most likely the monitor will run later after the conflicting monitor has passed.
There's a lot more there too. What is your coolant temp showing? That is used to help determine open/closed loop.