1998 Taurus Crankshaft Angle Sensor / Synchro / Cam Position Sensor

[rjs985]

My SES light lit recelntly. The ODB2 reader said the camshaft sensor was faulty. I read all related posts in this forum. I took of the sensor and inspected the synchro. both look great. It is allot different looking than the 97 taurus pics. For starters, the magnet on the sensor is not in the center, it is on the outter side. Second, the synchro's vein is not a C schape like the 97 pics. This vein is actually much smaller and is about 1/6 of a circle.

I verified that this is normal with the replacement parts offered me by Napa. Since the replacement synchro / "crankshaft angle sensor" looks the same, I decided to only replace the sensor.

I then replaced the sensor and after I started the engine for the second time, the SES light lit again and spit the same codes.

Now, I am confused. Am I barking up the wrong tree? Why does Napa call this a Crankshaft Angle Sensor? Did I take off the wrong sensor?

[GPFred]

Did you clear the code after doing the repair? If you didn't disconnect the battery or had the codes cleared, the light will remain lit until the code is cleared. Just trying to help diagnose the problem.

[shorod]

The Crankshaft Angle Sensor and the Camshaft Position Sensor would definitely be a different sensor. Which engine does your Taurus have? I don't think that there is an engine in the Taurus lineup that only uses one sensor, but I'd have to check my 1998 MY service manual to be sure. I guess technically the PCM could use camshaft position (with more than usual resolution) to determine crankshaft position, but I don't think Ford does that.

-Rod

[rjs985]

Originally Posted by GPFred

Did you clear the code after doing the repair? If you didn't disconnect the battery or had the codes cleared, the light will remain lit until the code is cleared. Just trying to help diagnose the problem.

I did both. I disconnected the negative lead on the battery while servicing it and cleared it with a laptop. This code came back both times after I did so.

[rjs985]

Originally Posted by shorod

The Crankshaft Angle Sensor and the Camshaft Position Sensor would definitely be a different sensor. Which engine does your Taurus have? I don't think that there is an engine in the Taurus lineup that only uses one sensor, but I'd have to check my 1998 MY service manual to be sure. I guess technically the PCM could use camshaft position (with more than usual resolution) to determine crankshaft position, but I don't think Ford does that.

-Rod

I have the SOHC v6 3.0L U. Apparently Napa doesn't sell the camshaft synchro. The looked it up and selected camshaft synchro and it came back as crankshaft angle sensor, with two options, with and w/o step on plug. It looks just like the cam synchro.

Anyways it looks fine. I took some digital pics of the vein and am going to look at it again tonight to see if it moved. Maybe it siezed?

I am also following a ford service manual for that trouble code. I am stuck at the part where I need a break out box ($$$) to test the resistance and voltage. It is all leading me down the path to a bad PCM.

I find it hard to belive an open or short all the sudden appeared in this circuit. It was a very cold morning when this errored (~10 deg faren). I could beleive a PCM problem. But now how do I replace/program that?

Is it time to send to the, gulp, dealer? I would hate for them to just start replacing parts and bill me.

[shorod]

You can carefully backprobe the connector for the CPS to see if it is outputing the appropriate signal.

-Rod

[rjs985]

Originally Posted by shorod

You can carefully backprobe the connector for the CPS to see if it is outputing the appropriate signal.

-Rod

How? Do I disconnect the harness and connect a meter to the two leads on the CPS or do I somehow tap into the two leads while the harnes is connected to the CPS?

What voltage should I look expect? And if I already replaced the CPS, does it mean the synchro is not spinning fast enough? I have the CPS off now and verified the vein in the synchro moved since the last time I looked at the vein.

[shorod]

To backprobe a connector, you insert pins/leads into the back side of the connector to make your measurement.

The service manual should explain what voltage to exect. I would expect it to be a square wave of 5Vdc amplitude. Ideally, you would use an oscilloscope to make this check, but a multimeter could work as well. If the Vdc measurement seems very unstable, try using Vac.

-Rod

[rjs985]

Originally Posted by shorod

To backprobe a connector, you insert pins/leads into the back side of the connector to make your measurement.

The service manual should explain what voltage to exect. I would expect it to be a square wave of 5Vdc amplitude. Ideally, you would use an oscilloscope to make this check, but a multimeter could work as well. If the Vdc measurement seems very unstable, try using Vac.

-Rod

I tested the wiring and everything else, per the service manual. It is all pointing at the PCM. Now I am having a hard time getting two parts places to agree on the correct replacement PCM. I would like to understand the PCM differences and calibrations. The service manual doesn't explain this at all. Just that it must be able to be reprogrammed out of the car. Some parts places say they have to some say they dont. Any ideas or thoughts?

[wafrederick]

You can get the sychronizer from the dealer only,dealer part only and is not cheap.