Crank position sensor test? -
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back > Models > Jeep Wrangler Forums > TJ Wrangler Technical Forum > Crank position sensor test?

FS: Wranger BRIGHT License Plate LED! Just $3! Great valueBlack Friday and Cyber Monday Sales at JeepHut.comThe Jeep Forum Discount is ON!

Unread 06-20-2010, 09:41 PM   #1
Registered User
Join Date: Mar 2010
Location: reno
Posts: 1
Crank position sensor test?

I have a 1998 Jeep Wrangler 2.5L. Manual Transmission and I am getting a P1391 code. I tested the cam position sensor and it tested ok. How do I test the crank position sensor?

nvwoody is offline   Reply With Quote Quick reply to this message
Unread 06-20-2010, 09:54 PM   #2
Registered User
2011 JK Wrangler 
Join Date: Aug 2004
Location: Norman, Oklahoma
Posts: 295
You might just remove it and clean it first, as the clutch wears the magnet will collect fragments and not read correctly, while its out inspect it for cracks.

2011 Flame Red Rubicon (2-Door) with every option.
SoonerYJ is offline   Reply With Quote Quick reply to this message
Unread 06-20-2010, 11:04 PM   #3
Registered User
1986 CJ7 
Join Date: Sep 2009
Location: Colorado
Posts: 43
Any chance you've got access to a scope?

That's the only way I know of ~really~ testing one.
1986 CJ7
2003 TJ
2012 Overland
"Temporarily Detained" maybe, but ~never~ stuck...
Unbalanced is offline   Reply With Quote Quick reply to this message
Unread 06-21-2010, 12:49 AM   #4
Registered User
2004 TJ Wrangler 
Join Date: Jan 2008
Location: Lincoln Nebraska
Posts: 3,246
A quick way to know is it will turn over, but it won't spark if it isn't working. The problem with that theory is however other things failing will do the same thing I.E. coil, cam sensor, and so on down the line.

I had a ZJ that those went bad every so often, we found out it was due to the valve cover gasket leaking, the oil would trickle down onto the CPS and cause it to fail.

Build Thread:
Dad's Build Thread:
OEM Fog Light Connectors, Conversions, and Extension Info:
JeepnBlake is online now   Reply With Quote Quick reply to this message

Quick Reply

Register Now

In order to be able to post messages on the forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools

Suggested Threads

Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. is not in any way associated with Jeep or the Chrysler Corp.