Got a puzzle with my '92 Legacy wagon (206K miles).  Haven't had any indications of problems, i.e. no CEL lit when it is running, but decided to see if any codes were in the ECU and got one:  one long blink three short blinks when I plugged the green connectors together and turned the ignition key to on (= cam angle sensor error).  Checked the cam angle sensor continuity and got about 1600 ohms and something over a pulsing .2 volt cranking the engine with a voltmeter attached to the sensor plug (factory manual says anything over 0.1 volt is good).  So it is putting out a signal and has good continuity so why the CEL code but no "notification" via a blinking check engine light when running?  And clearing the code with the multi-step procedure in the service manual doesn't clear it.  A glitch in OBD software or my specific ECU?  Runs fine otherwise, so anyone know what might explain the 13 and inability to clear it? 

Obd1 will not blink the CEL if there is a problem. Actually unless there is a direct issue with a sensor (like the ECU is getting no signal at all from it) often there will not be a code at all.

 

I would suspect the signal from the cam sensor isn't reaching the ECU.

 

Cam sensor should be making AC voltage, did you check AC or DC volts?

Sensor output was measured as "AC" volts.

Had similar problem, cleaned the contacts with some sandpaper and replugged it. Deleted all codes and was never seen again. (on a 1991 legacy)