For giggles, pull both those plugs and be sure they are gapped correctly, and not cracked....
The PCM will not go into "limp" mode as you think, be sure the coil didnt burn up... not likely, but it is possible
no spark on 2/5 cyl
ok a quick run down. I changed plugs on the 2007 Jku 3.8 6 spd. I wasnt done and the cylinder #2 wire was just hanging while I went to work then, my wife drives the jeep 2 blocks and the check engine light comes on, she sends me a text about the issue and I said "thats because I never hooked up the plug wire on #2 cyl" so, thinking this is no big deal I get home put the wire back on clear the code and start it up.........And it still misses on 2 and 5 cyl which means the coil so I buy a new coil,test the resistance on the plug wires,check continuity on the wires from coil to PCM,and new plugs,I disconect the Battery overnight ....And it still is not fixed does anyone know if something in the PCM goes into limp mode and needs reset like a reflash or maybe a hend held tuner like diablo intune would help ....... right now Im really in need of Ideas or answers :gluging:
1 - 15 of 15 Posts
The PCM will not go into "limp" mode as you think, be sure the coil didnt burn up... not likely, but it is possible
I am thinking you got the wires mixed up... if it was running fine before the tune I don't think you need a new coil NOW.
What kind of plugs did you buy....don't say e3.
Sent by horse and buggy
Sent by horse and buggy
TOTALLY FORGOT TO ASK THAT!!!
Yeah, super fancy plugs and the JK CAN-BUS system DO NOT get along! I have heard of good luck with aftermarket coils and wires- though I only run OEM .
Yeah, super fancy plugs and the JK CAN-BUS system DO NOT get along! I have heard of good luck with aftermarket coils and wires- though I only run OEM .
well the plugs are stock champions and no the spark plug wires are in their right location trust me there is no spark on 2/5 coil from the tests I performed this weekend it looks like the coil driver in the pcm has stopped working for that coil that the plug wire was disconnected on :suicide:
good news in a way! it was the PCM and its covered under the federal emissions warranty 8 year/80,000 miles wooo hooo:bounce:
Do the plugs and the CAN-Bus mix somewhere?Yeah, super fancy plugs and the JK CAN-BUS system DO NOT get along!
Well, I assumed so based on peoples postings about problems with non-OEM plugs. Namely E3.
Your pretty well versed in the JK though Ron, so I am guessing they in fact are NOT effected by CAN-BUS. That would mean that the wires arnt wither. That would mean that I may have skimped out on aftermarket plugs/wires based on faulty info.
The OPs problem is solved- but you could let me know if I am regurgitating faulty info.
Your pretty well versed in the JK though Ron, so I am guessing they in fact are NOT effected by CAN-BUS. That would mean that the wires arnt wither. That would mean that I may have skimped out on aftermarket plugs/wires based on faulty info.
The OPs problem is solved- but you could let me know if I am regurgitating faulty info.
Just another CANBus myth BSDo the plugs and the CAN-Bus mix somewhere?
So basically you almost finished a tuneup, forgot to tell your wife it wasn't done and burned up the PCM driving it with the plug wires dangling?
If that was the root cause, stinks that it would be that delicate. Glad the warranty covered it regardless.
Read a lot of complaints about E3's only for whatever reason.
If that was the root cause, stinks that it would be that delicate. Glad the warranty covered it regardless.
140k, the last 90k running NGK with no issues.Well, I assumed so based on peoples postings about problems with non-OEM plugs. Namely NGK.
Your pretty well versed in the JK though Ron, so I am guessing they in fact are NOT effected by CAN-BUS. That would mean that the wires arnt wither. That would mean that I may have skimped out on aftermarket plugs/wires based on faulty info.
The OPs problem is solved- but you could let me know if I am regurgitating faulty info.
Read a lot of complaints about E3's only for whatever reason.
Several Chrysler engines use Mopar NGK plugs & some use Mopar Champion plugs. If I remember right, 3.8s use Champion platinum plugs. And running an engine for to long with plug wires not connected will burn up the coil & coil driver.Well, I assumed so based on peoples postings about problems with non-OEM plugs. Namely NGK.
Your pretty well versed in the JK though Ron, so I am guessing they in fact are NOT effected by CAN-BUS. That would mean that the wires arnt wither. That would mean that I may have skimped out on aftermarket plugs/wires based on faulty info.
The OPs problem is solved- but you could let me know if I am regurgitating faulty info.
And Can Bus doesn't truely run things. Can Bus system relays info mainly. & there are several bus architectures use in cars. we have Can-C, Can-B, Diag Can-C, Can IHS, LIN bus & Powernet. and i think we got a new one coming out called Global Compact car or something like that.
so my theory on the PCM going bad was, the plug wire on #2 only that was not connected for an 1/8 mile must have let the voltage back feed to the PCM and knock out the coil driver circut for the 2/5 coil in the coilpack.you see the the coil always has a hot going to it and the PCM(coil driver)will ground to make the coil discharge to a plug..............just my thoughts:thankyou:
Makes sense about burning up the coil driver...
so finally i got time to post the results
it turns out the coil driver in the PCM burned out and the dealer replaced the PCM under the 8yr/80,000 mile fed emmission warranty:bounce:
it turns out the coil driver in the PCM burned out and the dealer replaced the PCM under the 8yr/80,000 mile fed emmission warranty:bounce:
1 - 15 of 15 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
JKOwners Forum
A forum community dedicated to Jeep Wrangler JK owners and enthusiasts. Come join the discussion about performance, modifications, classifieds, reviews, engine swaps, troubleshooting, suspension, and more!
Full Forum Listing
Top Contributors this Month
View All
Diode Dynamics
29 Replies
Fklein6768
24 Replies
Old Dogger
24 Replies
Recommended Communities
