GC check engine trouble

Apr 11, 2007 8 Replies

I have a 98 GC, 4.0 auto. The check engine light came on ant the code is P0720, output shaft speed sensor circuit. I got part # 1-04800879 (the sensor). Can somebody who has the factory shop manual scan me the troubleshooting/repair steps for this code.



The light has been on for a long time, but the JEEP was running fine. All of a sudden, it stopped shifting gears, stays in 1st, so it is now time to fix. I am going to change the sensor, but if I can get the directions from here, I want to go over the whole circuit.



Thanks John in Vegas



Thanks Bill. Jeff, Im not too concerned that I got the right one because the code reading says its the output sensor. When I bought the sensor, the dealer gave me a copy of the manual that explained the troubleshooting procedure for the whole circuit, but of course I cant find it. I guess I will crawl under it tonight and change it and hope the fault is in the sensor itself.

Thanks guys.

John > Bill sent a link that shows there are 2 speed sensors on the transmission.

I think I would go ahead and remove the driveshaft. Remember it's inch pounds. God Bless America, Bill 0|||||||0 mailto: snipped-for-privacy@aol.com

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OK you got me here. Why would I have to remove the drive shaft?

John > I think I would go ahead and remove the driveshaft. Remember it's inch > pounds.

More room for a BMFH! God Bless America, Bill 0|||||||0 mailto: snipped-for-privacy@aol.com

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I got the sensor changed, the check engine light is out, and it now shifts again. BTW, it was a little different than the directions, but the location was the same, Thank you.

Bill, do you have the directions for the trans. oil and filter change as well? I did it on my XJ and I think I remember that something was not exactly straight forward, but it was so long ago...

John > What Bill, does he administer the inch pounds one blow at a time? What's the

Hi John, I would drill and tap a drain plug in the torque converter, then change it like a Ford or GM. God Bless America, Bill 0|||||||0 mailto: snipped-for-privacy@aol.com

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I don't think drilling the torque converter is such a good idea, maybe the pan. Its got almost 100k on it, so I want to change the filter as well

John

"L.W. (Bill) Hughes III" wrote:

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