Crankshaft position sensor
Thread Starter
JK Newbie
Joined: May 2021
Posts: 1
Likes: 0
From: Bowie
Crankshaft position sensor
Hey y’all!
So, I’ll try to streamline this thought process.
2 weeks after we bought the Jeep, it died while driving it a few different times. My husband figured out that if he unplugged the crankshaft position sensor and plugged it back in, it would get us back home.
He bought one from oreillys just to see if that would fix it. We went another 2 weeks and coming home from Wichita he said he thought it had reduced power, but we went to pass a truck and it just started beeping and flashing lights and the CEL was flashing. It would still drive 60-65 but was like in a limp mode. We supposedly had bumper to bumper warranty so he said I’ll just take it in so i don’t have to mess with hunting it down. We found out later that they had changed our coverage plan at the original dealership but failed to tell us and and it wouldn’t cover anything electrical. The part that they said it needed (the crankshaft position sensor pigtail) wasn’t covered but we said well- go ahead as they kept assuring us they had their master mechanic working on it.
Ok. So they changed that and it still didn’t fix it. They Called us and said now it’s the PCM/ECM. That’s $999 and on back order, and asked if they wanted us to order it. He said no, we would order a remanufactured one and he could put it on himself. I hurriedly ordered one with overnight shipping from flagship one. They said it would be there Thursday. That’s cutting it really close, right!?
We paid $480 yesterday and hauled it home on the trailer.
The codes they were saying it was throwing were p0300 (multiple misfires) and p0335 (crankshaft position sensor). They had wrote in their paper P0355 (ignition coil #5) so we stopped and bought one of those on the way home and he changed that out first and it didn’t change it at all. Still turned over forever before it started, rough running due to misfires, no power and flashing CEL. So, i think that they mistyped that— meaning to write 335.
Anyways while he was underneath it he saw that the same CPS was still in it so he pulled it out and put the factory CPS in it and it started right up. No codes, no lights... ran fine. Seriously. **blank face**
Since i had already ordered a new electronic control module since that’s what the guy kept saying was the problem and my husband “fixed it” with a crankshaft position sensor swap, i cancelled the order to save $400 on a part we don’t need and can’t send back.
He called the service dept this morning and argued the price we paid yesterday for nothing and they said no- it is the computer because they put a brand new crankshaft position sensor and a used one in it to test it, but they never wrote it down or told us they did that until he asked this morning. Hmmm..
My husband thinks they didn’t really put one in it, or maybe they did try to change it out, but before they changed out the pigtail? One of our friends told us that their Jeeps have been very picky for all OEM parts. So My husband is going to stop and buy a new crankshaft position today.
My concern is —- could it be the computer still?
Bad connection?
Our friend didn’t think so bcz he said it wouldn’t go bad and then fix itself and back and forth if it was the computer?
Whaaaat is it???
I just don’t want to get stranded half way to Florida!
I need someone who has some common sense and knows the book protocol to think through the crankshaft crap.
So, I’ll try to streamline this thought process.
2 weeks after we bought the Jeep, it died while driving it a few different times. My husband figured out that if he unplugged the crankshaft position sensor and plugged it back in, it would get us back home.
He bought one from oreillys just to see if that would fix it. We went another 2 weeks and coming home from Wichita he said he thought it had reduced power, but we went to pass a truck and it just started beeping and flashing lights and the CEL was flashing. It would still drive 60-65 but was like in a limp mode. We supposedly had bumper to bumper warranty so he said I’ll just take it in so i don’t have to mess with hunting it down. We found out later that they had changed our coverage plan at the original dealership but failed to tell us and and it wouldn’t cover anything electrical. The part that they said it needed (the crankshaft position sensor pigtail) wasn’t covered but we said well- go ahead as they kept assuring us they had their master mechanic working on it.
Ok. So they changed that and it still didn’t fix it. They Called us and said now it’s the PCM/ECM. That’s $999 and on back order, and asked if they wanted us to order it. He said no, we would order a remanufactured one and he could put it on himself. I hurriedly ordered one with overnight shipping from flagship one. They said it would be there Thursday. That’s cutting it really close, right!?
We paid $480 yesterday and hauled it home on the trailer.
The codes they were saying it was throwing were p0300 (multiple misfires) and p0335 (crankshaft position sensor). They had wrote in their paper P0355 (ignition coil #5) so we stopped and bought one of those on the way home and he changed that out first and it didn’t change it at all. Still turned over forever before it started, rough running due to misfires, no power and flashing CEL. So, i think that they mistyped that— meaning to write 335.
Anyways while he was underneath it he saw that the same CPS was still in it so he pulled it out and put the factory CPS in it and it started right up. No codes, no lights... ran fine. Seriously. **blank face**
Since i had already ordered a new electronic control module since that’s what the guy kept saying was the problem and my husband “fixed it” with a crankshaft position sensor swap, i cancelled the order to save $400 on a part we don’t need and can’t send back.
He called the service dept this morning and argued the price we paid yesterday for nothing and they said no- it is the computer because they put a brand new crankshaft position sensor and a used one in it to test it, but they never wrote it down or told us they did that until he asked this morning. Hmmm..
My husband thinks they didn’t really put one in it, or maybe they did try to change it out, but before they changed out the pigtail? One of our friends told us that their Jeeps have been very picky for all OEM parts. So My husband is going to stop and buy a new crankshaft position today.
My concern is —- could it be the computer still?
Bad connection?
Our friend didn’t think so bcz he said it wouldn’t go bad and then fix itself and back and forth if it was the computer?
Whaaaat is it???
I just don’t want to get stranded half way to Florida!
I need someone who has some common sense and knows the book protocol to think through the crankshaft crap.
JK Jedi Master
Joined: Mar 2007
Posts: 14,800
Likes: 374
From: Midwest City, OK
Hi, Clementine. Sorry that your first post has to be about such a bummer experience. Troubleshooting electrical problems can be challenging, which is why those folks who have done a lot of work on a particular vehicle are usually the best resource: They know what common weaknesses in a specific vehicle's design cause certain issues because they've seen it a lot. However, based on your warranty description, it doesn't sound like you're dealing with a reputable dealer. In fact, I suspect that this vehicle had this problem before you bought it, and they did a little warranty wording trickery to ensure they wouldn't be on the hook to repair it. You may wish to obtain a Carfax report and see if maybe a visit to a lawyer is called for.
Meanwhile, last year a had a bit of trouble with my CPS and I'll describe that to you in case it should prove informative. But first, a bit of confusion for me. You wrote, "Anyways while he was underneath it he saw that the same CPS was still in it so he pulled it out and put the factory CPS in it and it started right up." Are you saying that the same CPS was the one you bought at O'Reilly's and that the factory CPS was the one that was originally in the vehicle when you bought it? Or that you bought a new OEM CPS and installed that?
Regardless, let me share my own tale of woe. Last year while driving the TransAmerica Trail across Oklahoma, I had very similar experience with engine performance and codes. In fact, I captured much of it on video; I'll post a link below in case you think that may be useful. Anyway, we were in the Great Salt Plains and it had rained heavily the night before. Driving through the water puddles on the plain, I had a check engine light similar to yours. I suspected it was water that had splashed up on some sensitive part of the vehicle (though I've done a lot of deep water fords in my Jeep in the past). We fooled with it, and had problems with it not starting, so called for a tow truck and towed it out of the park ourselves to wait for the tow truck. But after a few minutes the vehicle started just fine. Canceled tow truck and continued on, but decided to find an auto parts store and read the code the next day. The next day we found a Napa store, but their code reader did not read my Jeep's codes. Go figure. We decided to continue on, but a couple days later, with a very shallow water ford, my Jeep did it again. However, after about five minutes it started up with all codes cleared. So, we continued on. Upon return home, I did some research and decided to replace the CPS. Since it appeared to be a water intrusion problem, I also ordered the pigtail connector. Bought both parts from O'Reilly's. I installed the CPS, but the pigtail was in a very difficult to reach location. I figured it would be easier to change that when I had the transmission pulled next time for a new clutch (mine is a manual). When installing the new CPS, I put a bit of dielectric grease on the connector to help seal it against water. Bear in mind that I have decades of experience working on electrical systems--retired USAF avionics tech--and I wasn't willing to work on that pigtail until I had the transmission pulled so I could access the wire and make a proper repair. I also have a 3.8L, so mine may be more difficult to access than other configurations. Regardless, if you suspect that the dealer didn't change the CPS, did they really swap that pigtail? Anyway, my Wrangler has not had further problems. I haven't done any deep water fords since, but I have put a lot of miles on it in remote places. No further codes or other problems at all.
Here's the link to that part of the video where I first experienced the problem, though I'm not sure how informative you'll find it. Skip to 15 minutes to see the first time (skip ads--Google forces them on my non-monetized channel). The video series does return to this problem a couple times, but spread through various videos.
Good luck! Your Wrangler is an awesome vehicle with which to get out and about. I hope you get it fixed up ASAP and continue to explore your world.
Meanwhile, last year a had a bit of trouble with my CPS and I'll describe that to you in case it should prove informative. But first, a bit of confusion for me. You wrote, "Anyways while he was underneath it he saw that the same CPS was still in it so he pulled it out and put the factory CPS in it and it started right up." Are you saying that the same CPS was the one you bought at O'Reilly's and that the factory CPS was the one that was originally in the vehicle when you bought it? Or that you bought a new OEM CPS and installed that?
Regardless, let me share my own tale of woe. Last year while driving the TransAmerica Trail across Oklahoma, I had very similar experience with engine performance and codes. In fact, I captured much of it on video; I'll post a link below in case you think that may be useful. Anyway, we were in the Great Salt Plains and it had rained heavily the night before. Driving through the water puddles on the plain, I had a check engine light similar to yours. I suspected it was water that had splashed up on some sensitive part of the vehicle (though I've done a lot of deep water fords in my Jeep in the past). We fooled with it, and had problems with it not starting, so called for a tow truck and towed it out of the park ourselves to wait for the tow truck. But after a few minutes the vehicle started just fine. Canceled tow truck and continued on, but decided to find an auto parts store and read the code the next day. The next day we found a Napa store, but their code reader did not read my Jeep's codes. Go figure. We decided to continue on, but a couple days later, with a very shallow water ford, my Jeep did it again. However, after about five minutes it started up with all codes cleared. So, we continued on. Upon return home, I did some research and decided to replace the CPS. Since it appeared to be a water intrusion problem, I also ordered the pigtail connector. Bought both parts from O'Reilly's. I installed the CPS, but the pigtail was in a very difficult to reach location. I figured it would be easier to change that when I had the transmission pulled next time for a new clutch (mine is a manual). When installing the new CPS, I put a bit of dielectric grease on the connector to help seal it against water. Bear in mind that I have decades of experience working on electrical systems--retired USAF avionics tech--and I wasn't willing to work on that pigtail until I had the transmission pulled so I could access the wire and make a proper repair. I also have a 3.8L, so mine may be more difficult to access than other configurations. Regardless, if you suspect that the dealer didn't change the CPS, did they really swap that pigtail? Anyway, my Wrangler has not had further problems. I haven't done any deep water fords since, but I have put a lot of miles on it in remote places. No further codes or other problems at all.
Here's the link to that part of the video where I first experienced the problem, though I'm not sure how informative you'll find it. Skip to 15 minutes to see the first time (skip ads--Google forces them on my non-monetized channel). The video series does return to this problem a couple times, but spread through various videos.
Good luck! Your Wrangler is an awesome vehicle with which to get out and about. I hope you get it fixed up ASAP and continue to explore your world.