speedyquest Posted August 12, 2014 Report Share Posted August 12, 2014 Hello guys, I am looking for information about what exactly tells the ecu to go into its closed loop condition. I've done some searching but only came up with people discussing which thermostat to install. The reason I'm looking into this is because I recently built a v-mount setup for my car but at this point I believe its too efficient and isn't allowing the car to warm up enough to tell the ecu "ok dude, your all set" lol. I currently have a 180 degree thermostat installed and I'm guessing the first thing I could probably do is install a hotter one. Before I do that however I'd like to know the temp that the ecu looks for to go into its "closed loop". Any info or thoughts are appreciated, thanks. Allen Link to comment Share on other sites More sharing options...
mr-starion Posted August 12, 2014 Report Share Posted August 12, 2014 What your running temp? Link to comment Share on other sites More sharing options...
mr-starion Posted August 12, 2014 Report Share Posted August 12, 2014 Test your ecu coolant temp sensor. How does it run? Link to comment Share on other sites More sharing options...
speedyquest Posted August 12, 2014 Author Report Share Posted August 12, 2014 Well since I'm running the stock temp sensor currently I don't know what my actual temp is. I can only give you a position on the stock gauge. As far as the CTS working what does that have to do with? I will definitely need to get an accurate temp guage though. Link to comment Share on other sites More sharing options...
mr-starion Posted August 12, 2014 Report Share Posted August 12, 2014 It will affect the ecu knowing if the car is warm enough to be in closed loop. When doing modifications its always good to at least have a temp guage and a/f guage. Link to comment Share on other sites More sharing options...
speedyquest Posted August 12, 2014 Author Report Share Posted August 12, 2014 (edited) Well I know that, but the condition of my CTS isn't a factor here. I'm just wondering about the actual conditions that the ecu looks for. Hard data I guess lol. Edited August 12, 2014 by speedyquest Link to comment Share on other sites More sharing options...
89PalermoSHP Posted August 12, 2014 Report Share Posted August 12, 2014 Just out of curiosity, and I know this isn't exactly the information your seeking, is your CTS original or aftermarket? I had a heck of a time with my original one which was toast and found the aftermarket ones were junk. Put in a new OEM one and it made a world of difference. Link to comment Share on other sites More sharing options...
speedyquest Posted August 12, 2014 Author Report Share Posted August 12, 2014 (edited) I don't mean to sound un-thankful for you guys responding to this post but... did you guys read what I wrote? I'm not attempting to repair or diagnose anything. I am simply looking for information about when the ecu goes into a closed loop. My CTS is a non-issue. And to sate your curiosity it is not an oem stock CTS. I believe its one I purchased from Dad or rockauto taking care to ensure it was the correct one. Edited August 12, 2014 by speedyquest Link to comment Share on other sites More sharing options...
ucw458 Posted August 12, 2014 Report Share Posted August 12, 2014 The ECU goes into closed loop based on the CTS info alone. The FSM gives 4 temp references for testing the CTS. 32F, 68F, 104F and 176F Since 176F is the highest test point I'm willing to bet that around that temp the ECU goes into closed loop. Around 300-400 ohms or less. Having covered that, my setup has a stock temp 195F stat in it. If you look at my ECU when it's warming up you will see the temp spikes to 195 then the stat opens and the temp settles down to 176F and stays there. Idling, city traffic, freeway use, doesn't matter. It always stays around 176F. So if you are using a lower temp stat then your running temp could be colder than the ECU needs to see before it goes into closed loop. That would make it never go into closed loop. Link to comment Share on other sites More sharing options...
speedyquest Posted August 12, 2014 Author Report Share Posted August 12, 2014 (edited) Thank you ucw, and that is what I believe is happening. I won't know what temperature my system is getting to until I put in a different temp gauge (which I'll do soon), but I'm guessing my overly efficient radiator setup + low temp thermostat are causing this situation. Another thing to consider is that I havent even installed my aluminum radiator yet... that will exacerbate this too. Edited August 12, 2014 by speedyquest Link to comment Share on other sites More sharing options...
DMNDSTAR87 Posted August 12, 2014 Report Share Posted August 12, 2014 I run a 180degree tstat and i have both my radiator fans wired to come on at sametime and when fans fire up and its fairly cool temps outside my car sometimes will cycle between closed/open loop...just my 2 cents...Gig out Link to comment Share on other sites More sharing options...
StarquestRescue Posted August 12, 2014 Report Share Posted August 12, 2014 (edited) The o2 sensor must also be warmed up and working properly. The ecu test port repeats one blink if the the sensor signal is not operating normally. and goes to a steady on when it is. If the engine is running too rich the sensor can't warm up enough. Do you have a heated 3 wire o2 sensor? And if your foot is in the gas too far or air flow exceeds a certain point the ecu abandons closed loop. Edited August 12, 2014 by StarquestRescue Link to comment Share on other sites More sharing options...
Edde Posted August 13, 2014 Report Share Posted August 13, 2014 Testing the cts at upper limit temp is easy. Get it hot as it gets and throw an ohm meter across it. And test for the #1 code. Link to comment Share on other sites More sharing options...
speedyquest Posted August 13, 2014 Author Report Share Posted August 13, 2014 (edited) Well now that you mention the ecu error, I have a toggle that turns on an LED built right into my dash, and I've always had the error light flash oxygen sensor even when at "operating temp". I put that in quotes because of this situation where I don't think its reaching that temperature. Its interesting too because I planned on abandoning the stock oxygen sensor and instead using the output from my AEM EUGO wideband for the ecu. I should probably check to see that its heated... but I guess I'm curious now, how does the ecu know the oxygen sensor is working correctly? Edited August 13, 2014 by speedyquest Link to comment Share on other sites More sharing options...
dpstarion88 Posted August 13, 2014 Report Share Posted August 13, 2014 (edited) Pretty much what StarquestRescue said. The ecu knows the o2 sensor is working and turns off code 1 when the o2 sensor is up to temp. and is sending approximately 1V to the ecu. According to FSM it says to test for aprox. 1V from the o2 sensor while revving or "racing" the engine and while coolant temp. is between 185*F-205*F. Sounds like your ecu never receives that signal from the o2 sensor being bad. -Dave Edited August 13, 2014 by dpstarion88 Link to comment Share on other sites More sharing options...
StarquestRescue Posted August 13, 2014 Report Share Posted August 13, 2014 A wide band can only simulate a narrow band signal. The real deal is typically better than fake. Wide bands are also heated. The dip switches on the aem will need to be set correctly to simulate the signal. Link to comment Share on other sites More sharing options...
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