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weird flashing check engine light problem

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Old Apr 11, 2009 | 12:22 PM
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Default weird flashing check engine light problem

my check engine light is doing slow flash while the car is running. its as if i have a jumper in the plug you check codes with and its giving me a code 1 but there is no jumper in the plug. i get the same result with jumper in.

any ideas? counting on you RonJ for this one.
 
Old Apr 11, 2009 | 12:28 PM
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o and i forgot to mention the car doesn't have a misfire
 
Old Apr 11, 2009 | 12:33 PM
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Hi Kevin -- What year Civic/ECU/wire harness? Is it the Si? My first impression is that the service connector circuit has a short. What happens if you clear the ECU by removing the BACKUP fuse for a minute or so?
 
Old Apr 11, 2009 | 12:35 PM
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What model year? If it's OBDII try checking with a scanner, it might show you a code there.
 
Old Apr 11, 2009 | 12:45 PM
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sorry meant to put that info but i'm posting from my phone since i dont currently have access to a computer.

97 integra b18b with 00 civic si head. p28 ecu with odb2 to odb1 harness

 
Old Apr 11, 2009 | 02:18 PM
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When you insert a jumper wire in the service connector, you provide ground to the ECU. Your CEL is behaving as if the brown wire leading from the ECU to the service connector is grounded, despite having no jumper wire inserted. Disconnect the ECU connector that contains the brown wire leading to the service connector and test it for continuity to ground. There should be no continuity to ground unless the service connector is jumped. If you detect improper continuity to ground, check for damage in the brown wire, the ECU connector, or the service connector that is allowing the brown wire inappropriately to ground out.
 

Last edited by RonJ; Apr 11, 2009 at 03:13 PM.
Old Apr 11, 2009 | 02:46 PM
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Thanks ron i'll try this tomorrow when i'm home since i'm out of town.
 
Old Apr 11, 2009 | 02:50 PM
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Originally Posted by 315 Customs
Thanks ron i'll try this tomorrow when i'm home since i'm out of town.
Kevin, no problem. If the wire between the ECU and service connector is not grounded out, then you'll need to consider that the ECU is bad. Can you get a known good P28 ECU from someone to do a swap?
 
Old Apr 11, 2009 | 03:10 PM
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yea i'm sure i can find someone with a p28 if need be. i also have my stock LS ecu
 
Old Apr 11, 2009 | 03:14 PM
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Originally Posted by 315 Customs
yea i'm sure i can find someone with a p28 if need be. i also have my stock LS ecu
I assume you already tried clearing the ECU?
 



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