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Check engine and traction control lights (error code P0394)

wmiller2

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Joined
Jul 14, 2020
Messages
3
Location
Fenton, MO
At high speeds sometimes my check engine light and traction control lights come on and stay on while the power is reduced. The error code is P0394 and one suggestion for this code was to replace the Cam sensor B, bank 2. This did not fix the issue and I am at a dead end. Has anyone else had this issue and been able to correct it? I can drive around town mostly with no issue, but at highway speeds this happens and with the traction light on the power is cut drastically!! Thanks in advance for any help!!!
 
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wmiller2

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Joined
Jul 14, 2020
Messages
3
Location
Fenton, MO
Yes, 3.6 engine. 2012 6-Speed manual transmission. I am not sure if the mechanic replaced the sensor with an actual Mopar part? Have you seen or heard of this issue? thx
 

BLACKJKU

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Feb 22, 2020
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Huntington In
I thought that when the traction control light was coming on when it wasn't supposed to was a wheel speed sensor, but then the ABS would probably be on also.
 

tkracus

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Joined
Nov 7, 2020
Messages
1
Location
Ohio
Mine is doing the same thing and looking for help as well. I replaced the sensor bank 2 which from my reading was the drivers side. I will go through and get more snapshot data of when it happened but after replacing the sensor it has been driven without issue for several trips but the first time I've taken it up to 80mph is when it tripped again which was around the speed it had before.
 
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BlackBetty2014

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Jan 9, 2021
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2
Location
Virginia
Mine is doing the same thing and looking for help as well. I replaced the sensor bank 2 which from my reading was the drivers side. I will go through and get more snapshot data of when it happened but after replacing the sensor it has been driven without issue for several trips but the first time I've taken it up to 80mph is when it tripped again which was around the speed it had before.
Same here. Replaced: both CPS, spark plugs, coils, rockers and lifters on passenger side and the exhaust camshaft. It only happens on the highway and if I give it a little too much pedal. If I carefully press the pedal to increase speed it doesn’t do it. But I can make it happen if I press the pedal more aggressively. Also she’s throwing other codes like: lost communication with FCM/TIPM, left hvac door moved to far (weird huh). My next investigation is to pull the TIPM and look for issues there. Anyone else having this issues?
 

BlackBetty2014

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Jan 9, 2021
Messages
2
Location
Virginia
Here’s a screenshot of the codes.

CB2F02D4-6B12-42AC-A79E-56482F8E3C40.jpeg
 

Mnkytweet

Member
Joined
Dec 8, 2019
Messages
39
Location
Patuxent River MD
I also have a 2012 6-speed JKU sport and I would have similar problems on long drives(with highway speeds), but never had reduced power. I used to make regular trips between southern MD and NC on 17. It never failed, about 4 hours into the 5 hour trip, traction control and CEL would come on and cruise control would kick off. Cruise control could always be re-engaged and I never lost power.

A couple of times, I tried the "turn it off and turn it back on" trick(sometimes in a parking lot, sometimes enroute), but the lights would stay on until the Jeep had been off for a few hours. I never found a for-sure solution, but I did find that all 4 axles seals had problems keeping the fluid on the right side of the seal. I changes all 4 bearings and seals over the last few weeks.

I have a road trip planned soon and hopefully can prove that my problem was the wheel speed sensors getting dirty and gummed up. I'll follow up after the trip.
 
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Mnkytweet

Member
Joined
Dec 8, 2019
Messages
39
Location
Patuxent River MD
I also have a 2012 6-speed JKU sport and I would have similar problems on long drives(with highway speeds), but never had reduced power. I used to make regular trips between southern MD and NC on 17. It never failed, about 4 hours into the 5 hour trip, traction control and CEL would come on and cruise control would kick off. Cruise control could always be re-engaged and I never lost power.

A couple of times, I tried the "turn it off and turn it back on" trick(sometimes in a parking lot, sometimes enroute), but the lights would stay on until the Jeep had been off for a few hours. I never found a for-sure solution, but I did find that all 4 axles seals had problems keeping the fluid on the right side of the seal. I changes all 4 bearings and seals over the last few weeks.

I have a road trip planned soon and hopefully can prove that my problem was the wheel speed sensors getting dirty and gummed up. I'll follow up after the trip.
Success! No traction control lights on 6 hour trip each way. Keep your axles sealed and the wheel speed sensors clean
 

Kordax25

New Member
Joined
Jul 30, 2022
Messages
1
Location
Tennessee
2013 JKU Sahara: So I have what appears to be a solution to my P0394 camshaft position sensor bank 2 problem. Mine was going into limp mode. Check engine light and traction control light would come on. Always at highway speeds around 3,500 rpm and around 70 mph. I replaced the sensor with an after market part and then with a mopar part but it still was happening. I checked for 5 volts on the pigtail on both bank 1 and bank 2, both were good. I bought the wiring replacement but thought I would try one more thing before cutting into my harness. I replaced the CRANKSHAFT position sensor on the bottom side of the engine. Took 2 minutes to swap out and cost me $24. I have not had it happen since. Now mind you, mine was tripping basically every time I was on the interstate. On two hour trips, it wouldn’t be uncommon for it to trip 20+ times. I got really good at turning off the engine and turning it back on while moving. So, if you haven’t tried this yet, give it a shot.
 

Steve3237

New Member
Joined
Jan 25, 2020
Messages
2
Location
Colorado
2013 JKU Sahara: So I have what appears to be a solution to my P0394 camshaft position sensor bank 2 problem. Mine was going into limp mode. Check engine light and traction control light would come on. Always at highway speeds around 3,500 rpm and around 70 mph. I replaced the sensor with an after market part and then with a mopar part but it still was happening. I checked for 5 volts on the pigtail on both bank 1 and bank 2, both were good. I bought the wiring replacement but thought I would try one more thing before cutting into my harness. I replaced the CRANKSHAFT position sensor on the bottom side of the engine. Took 2 minutes to swap out and cost me $24. I have not had it happen since. Now mind you, mine was tripping basically every time I was on the interstate. On two hour trips, it wouldn’t be uncommon for it to trip 20+ times. I got really good at turning off the engine and turning it back on while moving. So, if you haven’t tried this yet, give it a shot.
I had the same symptoms with my 2014 Jeep Wrangler Unlimited. Based on your experience I replaced the Crankshaft Position Sensor. Got 8.5 miles on the highway before it threw code C0394 again.
 

Steve3237

New Member
Joined
Jan 25, 2020
Messages
2
Location
Colorado
But did you also replace the cam position sensor?
The cam position sensor was replaced, and when the problem continued the cam sensors were then swapped with no effect. The vvt solenoids were also swapped, the PCM was flashed, and the oil had been properly changed over the last year with no issues.