WJ engine speed circuit malfunction - JeepForum.com

 
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post #1 of 6 Old 03-23-2010, 12:39 PM Thread Starter
kjcrosby52
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WJ engine speed circuit malfunction

Codes are P0320 and P0725, intermittent problems include engine stopping on idle, speeding on idle, sometimes at highway speed a violent jerk, then trans goes into limp-home mode (no first or overdrive). Could it be the crank position sensor, or maybe just an intermittent bad wiring connection, or something else?

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post #2 of 6 Old 03-23-2010, 01:55 PM
ezflip
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I would start with the Throttle Position Sensor. They have been known to create every symptom you have described.

~James
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post #3 of 6 Old 03-23-2010, 02:25 PM
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P0320 indicates a bad crankshaft position (CKP) sensor. Without that sensor, the engine will run poorly if it runs at all.

Signals from the CKP sensor is also how the PCM gets engine speed information. The P0725 code indicates that is not happening.

To me it's a no brainer. Replace the CKP sensor.
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post #4 of 6 Old 03-23-2010, 02:36 PM
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Ahh ha, I didnt catch the two codes the first time I read it. Definitely start with the CKP. The connector may have just popped off or a wire frayed. So check that before replacing the sensor.

~James
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post #5 of 6 Old 03-29-2010, 02:41 PM Thread Starter
kjcrosby52
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WJ engine speed circuit malfunction

I replaced the crankshaft position sensor, all seems great for now. Since the problem was intermittent, only time will tell for sure. Removal is a chore because the space is so limited. Just 2 bolts to remove the starter working from underneath, but only space for about one notch of wrench turn, so it took awhile to turn them both out. I did not take the wires off the starter, just swung it up somewhat out of the way. The bolt that holds in the sensor took many little one-notch turns to get out, too, then it's hard to get a hand up in there to wiggle the sensor out. Prying does not work well, you just have to wiggle and pull and be patient. Then I pulled it all down to where I could get both hands on the connector and worked at that for a few minutes before it finally came off. Reinstallation was easy but also took time, one little wrench turn at a time. Be patient, it just takes persistence.
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post #6 of 6 Old 03-29-2010, 02:54 PM
rm2001wj
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I guess if you can put it up on a rack and had good selection of tools, it might not be so bad. Otherwise it is indeed a PITA. I ended up having mine towed to the dealership when mine needed replacement. Hope the problem is definitely solved.
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codes , engine speed , grand cherokee , obd-ii , wj jeep

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