Code 394

[Rich Ealahan]

2014 jku. With 142000 miles. So changed the head and gasket due to a blown head gasket. That part went well. Car runs great until i get the code 394 and Jeep goes into limp mode. Get both engine light and stability control light. So far i have done both cam position sensors, crankshaft position sensor, spark plugs, checked all grounds. Look good. Checked wiring harness. Looks good. Can’t. Help but to think it is caused by the new head. Never had a prob like this before i changed the head. I read intermittent voltage loss. What could cause this? Sick of spending money and time on this thing. Oh yeah. While I’m doing all this i also replaced almost the whole front end.

 

[tJKrider]

2014 jku. With 142000 miles. So changed the head and gasket due to a blown head gasket. That part went well. Car runs great until i get the code 394 and Jeep goes into limp mode. Get both engine light and stability control light. So far i have done both cam position sensors, crankshaft position sensor, spark plugs, checked all grounds. Look good. Checked wiring harness. Looks good. Can’t. Help but to think it is caused by the new head. Never had a prob like this before i changed the head. I read intermittent voltage loss. What could cause this? Sick of spending money and time on this thing. Oh yeah. While I’m doing all this i also replaced almost the whole front end.

Is there a ground strap from that head to the chassis/body? Just trying to think of what you may have taken off (and had to replace) when doing a head swap. If so, check the attachment locations to make sure they are robust...

 

[BLACKJKU]

Is there a ground strap from that head to the chassis/body? Just trying to think of what you may have taken off (and had to replace) when doing a head swap. If so, check the attachment locations to make sure they are robust...

This^^^^^^

I added a heavy extra ground from the neg battery post to my alternator.

 

[Rich Ealahan]

Other head. No ground on drivers side.

 

[Rich Ealahan]

Also upon further investigation. Last night i found oil leakage from cylinder #5 on the passenger side. Pretty substantial. This code can also be affected by oil pressure issues. Anybody have any info on this. I have yet to find any good outcome to this situation.

 

[Rich Ealahan]

Went and bought a 2017 grand Cherokee overland with a HEMI. Guess the wrangler goes in the garage until we can figure it out. Wiring harness removal and inspection may be next.