Fault code P0320 (How can I test crankshaft position sensor?)

[Shropshirewrangler]

Laid the Wrangler (2002 I6 auto) up for the winter, battery disconnected.

5 months later re- connected battery and started as usual.

Left it for 2 weeks and the battery was flat, jump start failed.

Fitted new battery, it now cranks well but won't start.

Used the built in diagnostics pulled fault P0320 Crankshaft position sensor.

But the actual meaning of the code, as I understand it, is that the E.C.M. is not receiving a signal from the C.P.S. so could it be a blown fuse, faulty wiring or something else?

Before skinning my knuckles and teaching the neighbours kids a new, blue vocabulary, is there a way to test the CPS in situ with a multi meter?

 

[glowell222]

Laid the Wrangler (2002 I6 auto) up for the winter, battery disconnected.

5 months later re- connected battery and started as usual.

Left it for 2 weeks and the battery was flat, jump start failed.

Fitted new battery, it now cranks well but won't start.

Used the built in diagnostics pulled fault P0320 Crankshaft position sensor.

But the actual meaning of the code, as I understand it, is that the E.C.M. is not receiving a signal from the C.P.S. so could it be a blown fuse, faulty wiring or something else?

Before skinning my knuckles and teaching the neighbours kids a new, blue vocabulary, is there a way to test the CPS in situ with a multi meter?

What a drag.

Check out this vid-I used this to test mine in the past.

 

[Shwiftypickle]

Best way to diagnose it would be to probe the signal wire with a lab scope and look at the wave form comparing it to a known good waveform. Also check your input power to make sure the pcm is sending proper voltage to the sensor.

 

[Shwiftypickle]

Also check for any abnormal play in the housing it mounts to.

 

[Shropshirewrangler]

Thanks for your help chaps.
Do crankshaft position sensors tend to give symptoms before dying or do they just crap out suddenly?

 

[CharlesHS]

You might see the tachometer read abnormally before the engine dies...
IF the engine dies you can pour cool water on the CPS and then crank over the engine; it should restart (will only work a few times before it doesn't).
I have recommended this procedure to members in our Jeep group numerous times while on the trail.

 

[glowell222]

Thanks for your help chaps.
Do crankshaft position sensors tend to give symptoms before dying or do they just crap out suddenly?

Sometimes you will see a code stored that says something along the lines of "pending crank position sensor failure", not sure of the exact wording. Personally, I didn't have any warning from a driving or performance perspective-it just would not start one morning, and the code was same as yours.

 

[Shropshirewrangler]

Sometimes you will see a code stored that says something along the lines of "pending crank position sensor failure", not sure of the exact wording. Personally, I didn't have any warning from a driving or performance perspective-it just would not start one morning, and the code was same as yours.

Thanks again - looks like grazed knuckle time

 

[glowell222]

Thanks again - looks like grazed knuckle time

It's actually pretty easy to get at from underneath, on the port side.