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any clues why blinking check engine light?

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I had my check engine light on for awhile, I replaced the sencors that were bad then took it back to see if there were anyother codes. No codes came up but the light was still on, they tried to erase the codes, and of course drove down the road three kms or so and the light came back on, took the car back and the tried clearing them again. They couldn't get them to clear so now I have a blinking check engine light. The mechanic said it could be a wiring problem. Any ideas?

I'd say Plugs / Plug Wires .. Do they have the CEL Come on w/ a loose gas cap in the early 90's roo's?

A blinking CEL means the problem is currently happening. A steady CEL means a problem was detected and noted. That's for OBD2...not sure if it's the same for OBD1. What sensor was the offender? A little more info on vehicle...year, model, miles, etc...

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A blinking CEL means the problem is currently happening. A steady CEL means a problem was detected and noted. That's for OBD2...not sure if it's the same for OBD1. What sensor was the offender? A little more info on vehicle...year, model, miles, etc...

Its a 92 Legacy with turbo. 220,000kms. No codes appear when plugged into the comp. Just replaced the 02 sensor knock sensor and airflow meter. Which caused the previously steady cel to turn off. then 5 min later started blinking, but no codes came up when checked.

Are the two green wires connected?

 

This being an OBDI car, all you have to do is plug two wires under the dash together, depending on what diagnostic you want to perform. Black wires is U-check mode, where you just turn the ignition switch to On and the CEL will flash the code at you. Green wires is D-check mode, where you drive the car around, and the ECU does an active diagnostic, checking for any codes that might be happening then. Either one works fine, I always do D-check.

 

But if it is in either of these two modes, the CEL will flash either the code at you, or flash steadily to say there are no codes. The CEL will continue to flash until the wires are disconnected.

  • Author
Are the two green wires connected?

 

This being an OBDI car, all you have to do is plug two wires under the dash together, depending on what diagnostic you want to perform. Black wires is U-check mode, where you just turn the ignition switch to On and the CEL will flash the code at you. Green wires is D-check mode, where you drive the car around, and the ECU does an active diagnostic, checking for any codes that might be happening then. Either one works fine, I always do D-check.

 

But if it is in either of these two modes, the CEL will flash either the code at you, or flash steadily to say there are no codes. The CEL will continue to flash until the wires are disconnected.

Im not to sure which wires to check, there are plenty of wires under there. If possible a pic would be awsome.

Another time i have seen a blinking flash is when the diagnostic indicator has been left plugged in or "the paperclip" in some of hte older cars (applies more to domestic though)

 

try taking the ecu completely out and let it sit over night. may just need a brake. electronics act weird sometimes.

 

good luck and keep us posted

 

Joe

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My 1990 legacy
well there is one side plugged in and the other side has a place for a connector but nothing is there. I wish i had a didgital cam to take a pic to show you.

On the photo above is my VW Vanagon/Subaru Legacy wiring harness. This is every wire that makes the engine run. The four bright yellow ones closest to you go to the ECU but see the green plugs right below them? Those two should not be plugged together normally. Same with 2 black ones that are 1 pin connector type. When plugged in one will show codes while driving, the other will only show them parked. Dont remember which one but I think the green ones are for drive mode.

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so if I just uplugg it nothing serious will happen. cause the green connector is plugged in on my car, but I didn't know anything about it so I just left it alone.

the green connector is the active diagnostic connector it should NOT be normally plugged in. It should ONLY be plugged in when you are trying to diagnosis a problem.

 

Unplug the green T connector.

Just a heads up. It is my understanding that the ignition needs to be OFF when changing this connector or the black one, otherwise the ECU can be damaged.

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I found the green plugs and they aren't plugged in. UI dont know about the black ones. Im not to sure which ones you are talking about. Just want to be sure before I start unplugging stuff. Not very confident with the wiring stuff. lol

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There should be two sets of plugs. One green and one black. They are both normally not connected unless you are doing some troubleshooting.

Great thanks guys unplugged both of them conectors and engine light is off. ( Awsome) I dont know why the mechanics I took it too couldn't figure that out. Both of the connectors were plugged in. Bot now I unplugged them and light is out. Thanks again.:)

K.I.S.S.-------------Keep it simple stupid, one of the best ways to diagnose a car problem. everyone makes the simple mistakes after you finish fixing the big problems. never fails.

 

 

 

 

 

 

 

~Josh~

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Well I un hooked the black connectors too get rid of the cel, like what was mentioned to do a few threads up. Everything was good when i unplugged the black connector, untill I had realized that my awd was not working with it unplugged. (Any other ideas) or why this happened? Thanks.

  • Author
Does your vehicle have the fuse for disabling the AWD?

No cant find the fuse. But the AWD works fine after I plugged the connector back in, Its just the check engine light is still on. But no codes.

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