ECU / ECM Woes!
#1
12-01-2011, 02:57 PM
ECU / ECM Woes!
Ok, this is a long one, but I really appreciate everyone's input....I'm losing my mind with this!
The truck: 1990 F150 / I6 4.9L 300 / 4x4 / 5-speed standard trans.
I posted about an issue that I had with my F150 a few weeks back on another forum and thought I would try here too. The issue went away for about two weeks, but it suddenly happened again today. The truck started running rough as in missing / jerking a lot and the check engine light came on so I had a mechanic try to read the code. He said he couldn't pull any codes and recommended that I replace the ECM, or as some people call it, the ECU. (FYI: The plugs & wires and distributor are all new.) This issue has occurred on and off since I bought the truck two months ago. Although the check engine light came on today, when I turn the key off and restart it, the light goes off and it runs good for awhile, but then the problem comes back! I figure that it's time to take care of this by replacing the ECU / ECM as advised.
I removed the ECM / ECU and here are the numbers as they appear on the unit:
9223 1012
E9AF 14A624 AA (GTE)
F0AF-14A459-AA
Also, there is a sticker on the plug of the unit that reads: 586 ECM and Made in Canada.
I called a local Ford dealership parts dept. and asked them how to locate the part and what part number is "right" since they don't make new ECM / ECU's anymore. They said according to the spec's of my truck (see above), that the original Engineering part # is: FOTF 12A 650 BB, but that doesn't match the number (F0AF-14A459-AA) on the unit I removed. Without knowing the history of the truck, I wonder if someone replaced the original ECM / ECU with the wrong one, thus causing the intermittent problem I have now with it running rough?
Anyway, the Ford parts rep said the part number that I should look for is: FOPZ 12A 650 UA.
I called NAPA to order the part, but they recommended that I use part number: FOTZ 12A 650 BB, which is a re-manufactured part for $120.00 and a one year warranty.
The calibration code from the door jam of the truck reads: 0-51H-R02
Do I need to have this code programmed into a replacement unit?
Before ordering any parts, I'm curious if anyone has dealt with this issue or has any advice.
Thank you!
-Nabor J
The truck: 1990 F150 / I6 4.9L 300 / 4x4 / 5-speed standard trans.
I posted about an issue that I had with my F150 a few weeks back on another forum and thought I would try here too. The issue went away for about two weeks, but it suddenly happened again today. The truck started running rough as in missing / jerking a lot and the check engine light came on so I had a mechanic try to read the code. He said he couldn't pull any codes and recommended that I replace the ECM, or as some people call it, the ECU. (FYI: The plugs & wires and distributor are all new.) This issue has occurred on and off since I bought the truck two months ago. Although the check engine light came on today, when I turn the key off and restart it, the light goes off and it runs good for awhile, but then the problem comes back! I figure that it's time to take care of this by replacing the ECU / ECM as advised.
I removed the ECM / ECU and here are the numbers as they appear on the unit:
9223 1012
E9AF 14A624 AA (GTE)
F0AF-14A459-AA
Also, there is a sticker on the plug of the unit that reads: 586 ECM and Made in Canada.
I called a local Ford dealership parts dept. and asked them how to locate the part and what part number is "right" since they don't make new ECM / ECU's anymore. They said according to the spec's of my truck (see above), that the original Engineering part # is: FOTF 12A 650 BB, but that doesn't match the number (F0AF-14A459-AA) on the unit I removed. Without knowing the history of the truck, I wonder if someone replaced the original ECM / ECU with the wrong one, thus causing the intermittent problem I have now with it running rough?
Anyway, the Ford parts rep said the part number that I should look for is: FOPZ 12A 650 UA.
I called NAPA to order the part, but they recommended that I use part number: FOTZ 12A 650 BB, which is a re-manufactured part for $120.00 and a one year warranty.
The calibration code from the door jam of the truck reads: 0-51H-R02
Do I need to have this code programmed into a replacement unit?
Before ordering any parts, I'm curious if anyone has dealt with this issue or has any advice.
Thank you!
-Nabor J
Last edited by nabor j; 12-01-2011 at 03:29 PM.
#2
12-01-2011, 03:21 PM
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#3
12-03-2011, 07:42 PM
First: it's not common for the EEC to spontaneously die. It happens, but it's rare. Read this thread:
http://www.fordf150.net/forums/viewt...p?f=21&t=97221
So I don't think you're at the point of condemning your EEC yet. There are a LOT of possible causes for misfiring, and there are about 20 reasons why the guy might not have gotten any codes (the most likely is that he didn't know what he was doing). So read this caption & follow the link in it to the full procedure:
Then try it yourself - I bet you get a few codes. DON'T run out & buy all the parts whose names are mentioned in those code definitions! Get a digital multimeter & a Haynes manual:
Second: You should also try to get your hands on a fuel pressure gauge (Sears ~$40, or free rental from some parts stores), a screw-in compression gauge, & a vacuum gauge (MityVac).
. 
Third: If you eventually determine that the EEC is bad, buy the one NAPA recommends. If it doesn't work, return it and try one from CarQuest, Parts+Plus, Advance, or O'Reilly. Stay OUT of the zone.
http://www.mustangcentral.net/tech/part.html
http://www.fordf150.net/forums/viewt...p?f=21&t=97221
So I don't think you're at the point of condemning your EEC yet. There are a LOT of possible causes for misfiring, and there are about 20 reasons why the guy might not have gotten any codes (the most likely is that he didn't know what he was doing). So read this caption & follow the link in it to the full procedure:
Then try it yourself - I bet you get a few codes. DON'T run out & buy all the parts whose names are mentioned in those code definitions! Get a digital multimeter & a Haynes manual:
Second: You should also try to get your hands on a fuel pressure gauge (Sears ~$40, or free rental from some parts stores), a screw-in compression gauge, & a vacuum gauge (MityVac).
. Third: If you eventually determine that the EEC is bad, buy the one NAPA recommends. If it doesn't work, return it and try one from CarQuest, Parts+Plus, Advance, or O'Reilly. Stay OUT of the zone.
http://www.mustangcentral.net/tech/part.html
#4
12-04-2011, 01:31 AM
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I'm just gunna say it isn't common, but it did happen to me.
Does your fuel pump continue to run whenever you turn the key to run, but don't start the truck? If the eec is working correctly it will prime and shut off.
My "new" eec isn't code matched, I went to a junkyard and pulled one from another inline 5 speed truck, is it the correct one? No. Does it work? Yes.
My dad pulled one from a parts truck his buddy has, it's a 302 auto, just for the heck of it and of course it did nothing, but I did notice the one sticker on it says it's for a car, like a Taurus or something. Not sure how that makes sense.
Does your fuel pump continue to run whenever you turn the key to run, but don't start the truck? If the eec is working correctly it will prime and shut off.
My "new" eec isn't code matched, I went to a junkyard and pulled one from another inline 5 speed truck, is it the correct one? No. Does it work? Yes.
My dad pulled one from a parts truck his buddy has, it's a 302 auto, just for the heck of it and of course it did nothing, but I did notice the one sticker on it says it's for a car, like a Taurus or something. Not sure how that makes sense.