crankshaft position sensor error??
 

Here goes one for the electrical / engine people....

My 1997 LSI runs and performs perfectly. It recently had its timing
belt, waterpump and some pulleys changed. All back together and it
runs like a top.

Problem: The check engine light comes on when you start it and
remains on. It is sending the code for the crankshaft position
sensor. Sensor tested fine, but changed it anyway. No luck. Did
complete troubleshooting of harness etc. per Subaru manual and all
checks ok. The crank pulley looks fine too with all of its teeth in
line where they belong for the sensor.

You can clear the code, start the car with no CEL on, but after you
shut it off, and restart, on pops the light. Using the OBDII tester,
when the ignition is on but not running you can clear the code fine,
and no codes found. A soon as the car is started, up comes the code
on the meter, and the next time the car is started, on comes the
light.

My mechanic gave up. He said that when these crank sensors go bad the
car does not run, and this one runs great!

I am at a loss here. Anyone else experience this and have a remedy or
suggestions?

Another question: The manual refers to two crank sensors, and one cam
sensor, but we can only find on each, the ones in the front center of
the engine under the alternator. Are there one or two cranks sensors?
Any help with its location and answers to above much appreciated!!

Happy Spring!!

Re: crankshaft position sensor error??
 

Hi there,
There three sensors in all, they all work together to produce the ignition point.

There are two above the crank, the one that is a 12o'clock is sensor 2. Sensor 1. is at 11o'clock. all looking from the front.

Sensor 1 gives a pulse every 30 degrees, Sensor 2 gives a set of pulses, 1, 3, and 2 sets, per rev. This tells which one for the 3 cylinders it is at. 3,2,5, or 4,1,6. The cam sensor then tells which of the 3 sets is the one that the cam shaft is ready for. Hey simple isn't it.:rolleyes:

Sensors 1 and 2 are the same part no. I think it was this pair or it may have been one of these and the cam sensor, that were the same, but there are only two part no for the three sensors.

Harvey. ;)

there are 2 crank sensors they are right below the alternater and right beside each other sounds to me like you are a tooth off on the timming.

The SVX has two camshaft sensors, and one crankshaft sensor. The two sensors that you see are the crank sensor and one of the cam sensors. If you are standing in front of the engine, the 2nd cam sensor will be on your right towards the front of the engine (near the cam gears). It is mounted onto a bracket.
Here's where it gets tricky though. Subaru uses one of the cam sensors AS a second crank sensor. So, technically it has two crank sensors and one cam sensor, even though if you replaced them all you would need to order one crank sensor and two cam sensors. WEIRD, HUH?!

We had a car in our shop last year that did something similar. It had a check engine light that would not go away. We replaced the sensor that the computer said was bad. No luck. Checked the harness, all connections, etc. No luck. So we called Subaru for help. They said the ECU might be faulty and throwing codes for no reason. So, we changed the ECU. No more check engine light!


Being a tooth off on timing would make your car run rough, so I doubt its that.



Dave

good info bad ecu hmmmmmm
 

Thanks everyone for your input thus far.

RedSVX95's description sounds the closest so far. Both "crank" sensors visable under the alternator are actually different.

How would one know if the timing was off a tooth? Would the car still run as well as it does if that was the case?

Any other ideas guys besides replacing the ecu?

Many thanks.

What would cause this in the ecu? Ideas? Also, where is the ECU located?

PS The code it is throwing pertains to the true crank sensor which has been replaced.