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ECU refuses to reset or clear

Posted: Sat May 28, 2011 8:02 am
by Amoxin
Hey, so I have done the reset procedure for clearing codes, disconnected the battery over night, even removed the ECU, inspected, and re-installed. I cannot get these codes to go away! They are still there on the ECU before I even start the car for the first time after the supposed reset. Think my wiring is shot? How often do these fail? Any first hand experience on this subject? Thanks!!

Re: ECU refuses to reset or clear

Posted: Tue May 31, 2011 7:35 pm
by Legacy777
What codes come up? What codes come up when just doing the active mode diagnostic with the green connectors?

Re: ECU refuses to reset or clear

Posted: Tue May 31, 2011 8:59 pm
by Amoxin
Hey, thanks for the response. the codes that are sticking are...

14 Fuel injector inoperative (Abnormal signal emitted from monitor circuit)

15 Fuel injector inoperative (Abnormal signal emitted from monitor circuit)

16 Fuel injector inoperative (Abnormal signal emitted from monitor circuit)

17 Fuel injector inoperative (Abnormal signal emitted from monitor circuit)

22 Abnormal voltage produced in knock sensor monitor circuit

23 Abnormal voltage input entered from air flow sensor

24 Air control valve inoperative (Abnormal signal produced in monitor circuit)

32 Oxygen sensor inoperative

41 Faulty learning control function

49 Use of improper air flow sensor


and the code that pops up after about 5 minutes of driving with the diagnostics mode enabled is 22 (Knock sensor)

Re: ECU refuses to reset or clear

Posted: Wed Jun 01, 2011 6:28 pm
by Legacy777
I would start with the knock sensor since it is the code that comes up under the diagnostic mode.

Have you downloaded the service manual and checked the knock sensor using the diagnostic procedure listed?

http://bbs.legacycentral.org/viewtopic.php?f=12&t=14485

What year and model legacy do you have?

Re: ECU refuses to reset or clear

Posted: Thu Jun 02, 2011 8:20 am
by Amoxin
Problem SOLVED. I picked up a white connector knock sensor today, tightened it down to 17 ft lbs and now I have no codes. This has got to be one of the strangest management systems ever...most of the signs were pointing towards ecu failure. I own a 1991 SS.

Thanks!

Re: ECU refuses to reset or clear

Posted: Tue Jun 07, 2011 5:55 pm
by Legacy777
Glad you got it taken care of.