Hello,

 

I have a 91' Legacy 2.2L (169K miles) that the check engine light has been on for about 1 year. Half a year ago I checked the diagnostics (connected the cables under the steering wheel) and recieved about ten codes that didn't make much sense. Recently I took the car to the dealership and they said that they can't figure out why the light is on and suggested that we change the computer for ~$850!!! The wagon runs great but I need to get an emission test, In CA the light has to be off but functional (ie. comes on with first turn of the ignition) any suggestions?

 

The previous owner said that one time the light was on and the dealership said that it was b/c she had overfilled the gas tank. They charged her ~$100 and turned it off.

 

Thanks in advance,

Kirk

If you clear the codes it should initially put the light off and then run it until the light comes on again - do another code read this should give you a better idea of what the problem is.

 

Take a note of any codes stored and post them here.

 

Regards

 

DaveH

Battery disconnect for an hour. Idle the engine up to operating temp. Switch off. PRESTO!

You can find all the code information as well as reset procedures on my site. Go to the notes & tips section.

 

Also to reset the ecu you can pull the EGI/TCU fuse for 30 min. I believe it's fuse # 14 in the dash fuse panel.

 

Once you have the ECU cleared....recheck the codes and see what comes up.

OK, I reset the ECU and re-checked the error codes. The culprit appears to be the atmospheric pressure sensor circuit (#45).

My chilton manual has information about a pressure switch but no pressure sensor. Any help will greatly be appreciated.

 

Kirk

I never heard of this sensor.

Where are you in San Mateo? I am on South Fremont.

The atmospheric sensor on the non-turbos is in the ECU itself......unfortunately.....the only cure is to replace the ECU......

 

Does the light immediately come on after resetting the ECU....or does it take a while?

 

If it doesn't immediately come on, you could try resetting the ECU close to the emissions place and hope it doesn't go on.

 

Since your car is OBD1, they can't plug into it and figure drive cylces, etc.

Hey Kirk, thank you for posting this thread.

 

And I big thanks to Josh for pointing to his website where I could find out the somewhat complicated (to me) procedure for reading, clearing, and resetting codes.

 

Our son has an '87 GL-10 turbo 5-speed wagon, I have an '86 GL carbed 5-speed wagon, and our daughter recently purchased a '90 Legacy FI 5-speed wagon. All super cars. The "check engine" light has been on since Jenny bought the Legacy. I tried to use the procedure in the Haynes manual and failed to even locate the wire they said should either be disconnect or connected... frustrating. Your description, Josh, is clear, concise, and complete, and I'm now confident I'll be able to find the necessary wires under the dash and resolve the check engine light problem.

 

Much obliged to this forum. Sincerely, Rick Johnson

make a bulb bypass system using a timer circuit:headbang: