I need to check the cam and crank sensors in a 90 Legacy as they are suspect (pulled code 11 from ECU). Is there a good way to check the crank angle sensor before replacing it at a cost of $300? Same question for the cam angle sensor. . .

Either/both sensors are little more than a coil wrapped around a center that sense the proximity of a metal bit on the back of the crank/cam pulley. So, you would use an ohmmeter. As to the value, I just looked and couldn't find one, but I would *think* in the neighborhood of 500 ohms. (I am sure someone will be by that knows) Let's just say, if "open" or "shorted", you can consider the sensor "dead".

 

Remember too, as these cars age, there is a whole lot of wiring (and several connectors) between either of these sensors and the computer. A closed wire seldom "goes bad", but connectors do.

I had the same problem, crank sensor giving errors in my 91 legacy. Took it out and cleaned the connectors with a brush and some connector (contact spray) put it back and sprayed thin layer of waxcoat over it to keep any moist and dust out. Never stopped working since.

Yeah, both of those are in line with what i was thinking. Before I replace the thing, I want to make sure it is really bad.

Anybody knows why a crank position sensor is around 300$ 92-94 and 25$ 95 on? How can such a simple part cost so much and then almost nothing? I guess the're not interchangeable?

Use an analog meter set on the lowest setting. When the metal tab passes by the sensor, it generates a small voltage spike. You can test this by hand cranking the engine. Also check for any opnes or shorts with an ohm meter. Usually if the car says the sensor is bad, its bad. Not much gray area here. Get one used from someone here, thats what i did.

 

 

nipper

Usually if the car says the sensor is bad, its bad. Not much gray area here.

 

 

I completely disagree with this statement.

 

My own experience and countless stories here on the board show that faulty connections often lie at the heart of CELs coming on for a sensor.

 

ESPESCIALLY the crank sensor. In fact simply tapping the key to *start* quickly, but not long enough for the engine to fire, will throw *ghost* codes for Crank, Cam, starter, or all 3.

 

I ussually ignore those codes entirely until EVERYTHING else has been checked.

i consider that part of the sensor, i should have clairified.

 

nipper

i consider that part of the sensor, i should have clairified. I meant to say the sensor circuit (which does include the connector).

 

nipper

 

PS, another possability (a longshot but it happens) is that a tooth is missing off the ring that generates a pulse for the sensor.