ECM test
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Intermediate
Joined: Jan 2010
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From: Canada
dcfatboy - this was after the bike was driven for 25-30 min and had sat for a few hrs. it was accross the terminals. (not running)
Old gunny - I'm inclined to aggree.
I'm getting the ECM tested on Mon. if it fails at all I am considering a thundermax ecm.
I'll let you know what turns up!!
Old gunny - I'm inclined to aggree.
I'm getting the ECM tested on Mon. if it fails at all I am considering a thundermax ecm.
I'll let you know what turns up!!
Last edited by drakenkade; Jul 17, 2010 at 01:29 AM.
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Intermediate
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From: Canada
OK went to the local HD dealer and.... the bike temp sensor wasn't being read by the ECM. I bought a new temp sensor and sure enough it made no difference. I wasn't really expecting it to as there isn't much to a temp sensor. I think that the temp sensor circuit in the ECM is fried. Also, one of the temp sensor wires was bare in the same spot that a ground wire had shorted against the pos. battery terminal. An all around crappy situation. At this point I think my choices are drive the way it is with the 100 or so miles to a tank and crap cruising conditions or replace the ECM.
Only problem with replacing the ecm is I have no idea where to turn. costs almost the same to put in one of the closed loop systems, (and I am not sure which is best for me) as it does for the stock.
Any suggestions or comments???????
Thanks
Only problem with replacing the ecm is I have no idea where to turn. costs almost the same to put in one of the closed loop systems, (and I am not sure which is best for me) as it does for the stock.
Any suggestions or comments???????
Thanks
Road Warrior
Joined: Mar 2008
Posts: 1,691
Likes: 3
Not relevant now, but per the original question. Easiest, though not easy, is verify the data you get from the ECM against direct sensor readings. Similarly the outputs aren't what's reported, i.e. the actual pulse width is not the reported pulse width. Mostly that takes a scope and a breakout box you can't buy makes it a lot easier. From a practical perspective you assume it is working fine until faced with evidence it definitely is not working. Like it keeps reporting an error that cannot possibly exist.
PS: hehe, guess I should have finished reading, seems relevant now.
PS: hehe, guess I should have finished reading, seems relevant now.
Last edited by LilBudyWizer; Jul 20, 2010 at 08:58 PM.
Club Member
Joined: Feb 2007
Posts: 1,678
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OK went to the local HD dealer and.... the bike temp sensor wasn't being read by the ECM. I bought a new temp sensor and sure enough it made no difference. I wasn't really expecting it to as there isn't much to a temp sensor. I think that the temp sensor circuit in the ECM is fried. Also, one of the temp sensor wires was bare in the same spot that a ground wire had shorted against the pos. battery terminal. An all around crappy situation. At this point I think my choices are drive the way it is with the 100 or so miles to a tank and crap cruising conditions or replace the ECM.
Only problem with replacing the ecm is I have no idea where to turn. costs almost the same to put in one of the closed loop systems, (and I am not sure which is best for me) as it does for the stock.
Any suggestions or comments???????
Thanks
Only problem with replacing the ecm is I have no idea where to turn. costs almost the same to put in one of the closed loop systems, (and I am not sure which is best for me) as it does for the stock.
Any suggestions or comments???????
Thanks
Road Warrior
Joined: Nov 2007
Posts: 1,984
Likes: 7
I believe TickTock is right. I don't think just Part of a ECM goes.
Go back to basic.
Parts, sensors, connectors both electrical and mechanical.
Then cause I went back and read this again there is tuning.
Looking at the parts on it I would think it needs tuning. That 55mm TB needs tuning to work on any bike.
Go back to basic.
Parts, sensors, connectors both electrical and mechanical.
Then cause I went back and read this again there is tuning.
Looking at the parts on it I would think it needs tuning. That 55mm TB needs tuning to work on any bike.
Last edited by Old Gunny; Jul 21, 2010 at 03:38 PM.
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Intermediate
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From: Canada
OK traced all the temp control sys. have continuity in all the lines and the intake and head temp sensors appear to be working fine.
Now I am really at a loss as to what to do next. I am leary of getting a new ECM due to the cost and uncertainty that it will correct the problem. Also, I was considering a thundermax or Twin tec tcfi III but I can't find anything good written about them. SOOO... If anyone has any ideas let me know.
I appreciate all the help so far... It really sucks when you spend this much money/time on a engine to have an electrical problem.
Oh ya. The bike was fully dynoed and running great 101hp 100tq. that is with a not so hi performance exhaust (2 into 2 @ 1/4 ") loud and cool looking but I plan on building a proper sys.
Now I am really at a loss as to what to do next. I am leary of getting a new ECM due to the cost and uncertainty that it will correct the problem. Also, I was considering a thundermax or Twin tec tcfi III but I can't find anything good written about them. SOOO... If anyone has any ideas let me know.
I appreciate all the help so far... It really sucks when you spend this much money/time on a engine to have an electrical problem.
Oh ya. The bike was fully dynoed and running great 101hp 100tq. that is with a not so hi performance exhaust (2 into 2 @ 1/4 ") loud and cool looking but I plan on building a proper sys.
Last edited by drakenkade; Jul 22, 2010 at 08:32 PM.
Road Warrior
Joined: Mar 2008
Posts: 1,691
Likes: 3
Are you throwing DTC codes for the head and intake temps or just not getting reasonable data off the ECM? I would think if you're throwing DTC codes then it would fallback on a reasonable default value. If it's not detecting the error then it likely uses whatever it's reporting.
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Thread Starter
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Intermediate
Joined: Jan 2010
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From: Canada
No DTC codes. Dealer used their diagnostic software and said the ecm was reading the bike a 40' and was therefore in cold start mode. Checked the two sensors in that circuit seem the be working. I just don't know enough about the sys to know where to go next??? Is there any other wiring I should check? I understand that the CHT and IAT require a 5v supply signal from the ecm. But, I don't know how to measure that. I only checked the lines for continuity.????
Thanks
Thanks
Road Warrior
Joined: Mar 2008
Posts: 1,691
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You should get 5V on the line without the sensor. With the sensor the voltage drop would depend upon the temperature, i.e. resistance the sensor presents. There's effectively a second resistor in the ECM and it's reading the voltage between the two resistors. With the circuit open the supply voltage should float 5v above ground. Complete the circuit and the drop across both is 5V and how much is across the sensor tells the resistance through the sensor relative to the second, fixed, resistance.
Since you have two temperature sensors out though it may not be that part that's bad, but, rather, something in common to both. That's the A/D converter that converts the voltage into a number the ECM can use. If so both would look find, but the value the ECM reports would be bad. If you're not getting 5V across the two lines when open then the ECM is definitely bad. You could actually hook a battery up to the sensor on a bench and a heat source to play with it. If you have the specs on it, i.e. how the resistance varies with temp, you could prove it's good or bad fairly easily.
Since you have two temperature sensors out though it may not be that part that's bad, but, rather, something in common to both. That's the A/D converter that converts the voltage into a number the ECM can use. If so both would look find, but the value the ECM reports would be bad. If you're not getting 5V across the two lines when open then the ECM is definitely bad. You could actually hook a battery up to the sensor on a bench and a heat source to play with it. If you have the specs on it, i.e. how the resistance varies with temp, you could prove it's good or bad fairly easily.