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-   -   2014 3.6 Check Engine Light Help (http://www.jeepgarage.org/f107/2014-3-6-check-engine-light-help-59670.html)

Sh0rtBus 05-08-2013 06:24 AM

2014 3.6 Check Engine Light Help
 
So my brother in law wakes me up early this morning....which is why I'm now on here earlier than usual......and tells me he can't find the battery in the GC to jump his car off. So I get dressed and go out to help him. He said he found the positive terminal and thinks he found the negative too. He had it all hooked up except to his car so the horn doesn't wake up the neighborhood. He hooks it up and I start his car and evening seems fine. I get in the GC to pull it back in the driveway and low and behold I noted have a CEL. WTF.

Any insight as to why I now have a light just from using it to jump another vehicle? I used it a couple weeks ago to jump start my Wrangler and it worked just fine, no CEL. WTF did he do? Taking it to the dealer to get it checked since I have to pick up my plates and other key anyway. Just don't want to be surprised with a bill because he screwed something up on my new vehicle.

padgett 05-08-2013 07:50 AM

Re: 2014 3.6 Check Engine Light Help
 
Without knowing what the code is, there is not much to say. If the engine was running and you disconnected from the other car, there may have been a surge. Ask the dealer for the code when you take it in.

ps The MIL light might go off the third time you start the car, let us know but the code will remain in history.

AZhiCntry 05-08-2013 10:14 AM

Re: 2014 3.6 Check Engine Light Help
 
Improper jump starting can damage the regulator diodes in the alternator. Have the dealer check for codes.

Sh0rtBus 05-08-2013 11:44 AM

Re: 2014 3.6 Check Engine Light Help
 
CEL did finally go out after about the 6th time I started it. I'll have them check the code when I take it in for its first oil change here in a week or so.

And I'm curious.....how does one improperly jump start? Only thing I could guess is maybe reversing polarity of the cables.

And just so it's clear, he'd already attempted to use it to jump off his car before ever coming to get me.

padgett 05-08-2013 02:40 PM

Re: 2014 3.6 Check Engine Light Help
 
What happens is that his battery is dead and your is charged. You connect the two and most people will start the jumper to boost the charge. The alternator goes to max output. The jumpee starts his engine and removes the jumper cables without shutting down the jumper.

ELI the ICE man takes over and suddenly the jumper alternator is at max charge and the sink goes away. Current (I) is traded for voltge (E) and you get a spike.

Now this seems to be the second case (...dead) where a 14 may have taken a surge. Be interesting if you have a C2101 code (voltage over 16.5v) in history.

ps proper way is to shut down the jumper vehicle (better to shut both down first) and then remove the ground jumper cable then the positive. Best way is to use a jump box.

Sh0rtBus 05-08-2013 03:03 PM

Re: 2014 3.6 Check Engine Light Help
 
I'm pretty sure I did it the same way when I jumped my '11 Wrangler, though. Hooked up the cables to the Wrangler, started the GC, hooked up the cables, then started the Wrangler. Let it sit for a minute and then remove the cables. But I probably removed the cables from the GC first since they were closest to me on the driver's side of the Wrangler (GC was parked on driver's side of JK). So guess that could explain it.

jacko15 05-08-2013 10:00 PM

Re: 2014 3.6 Check Engine Light Help
 
Padgett, I wonder why the owners manual doesn't mention shutting down the jumper vehicle before removing the cables? What you say makes sense, you'd think they'd say that in the manual.

padgett 05-09-2013 07:47 AM

Re: 2014 3.6 Check Engine Light Help
 
Probably because in the last century, electronics were designed for erratic electrical systems. At the Millenia I was surprised how many computer controlled cars of the '80s were still going strong. Cars were more reliable than televisions. While there have always been trouble areas (e.g. ignition control systems primarily in the secondary circuits that handle 40,000-80,000 volts).

There is a lot missing from the manual (like how to remove the cargo cover) and it is still over 600 pages. For that matter there is a lot missing from the service manual and it is almost 400 MB on a CD (and I have contacted CJF about the missing pieces).

What I am seeing in other posts is that the revised electronics in the '14 may be more successible to surges than earlier years. If a '14 were here, I'd be thinking about adding some serious surge protection (like in a home system - not hard) and making sure every ground was tight.

All of my cars have full instrumentation and could usually spot a bad ground/failing battery easily - the temperature and oil pressure guages would flick with the turn signal. With digital signals from a seial bus (OBD) this could be masked by the frame rate.

This is nothing new, I've been studying the effects of surges and spikes in electrical systems since the '70s & on another forum am helping with an electrical shutdown in a diesel (took out fuel cut-off solenoid).

It just seems like every year electronics has been becoming more succeptible to power issues - computers have been for years but protection is built into the power supplies. Do see a few 8.4 questions in the forum but the entertainment system seems to be better protected than the powertrin controls.

Would not be surprised to see a TSB come down for '14s about checking ground wire connections.

jacko15 05-09-2013 08:17 AM

Re: 2014 3.6 Check Engine Light Help
 
When I took delivery of my '14 the salesman told me to NEVER jump start it. He said he got this info from Chrysler. He told me if the battery died to call roadside assistance and have it hauled in to the dealer. I mentioned this on another thread a while back and was told that since the manual had jumping instructions that my salesman was full of it. After what you've just said I'm inclined to believe what he told me. Better safe than sorry.

padgett 05-09-2013 09:24 AM

Re: 2014 3.6 Check Engine Light Help
 
I just carry a jump box. AAA trucks usually have one. Nice clean power and not a big enough battery to load the alternator. $35 or less on sale & fits in the rear seat footwell with the seats folded.

That said, a battery acts like a really big capacitor and is a major part of the power filtering system of a car.

Back in the day, alternators could not put out enough power at idle to be a problem but in the last few decades, 100-200A alternators have been the norm. I have replaced a 94A peak (about 40A at idle) alternator with a CS-144 in my little RV that can put out over 100A at idle.

Also once upon a time the hot side of the alternator and jumper cables attached directly to the battery so there was little chance of a resistive/bad connection. Today particularly with the relocation of the battery, there is liable to be a splice/connection in the middle. If loose, wellll.

BTW there is a note in the jumping procedures not to use anything greater than 12v but does not go into the potential for surges/spikes.

Do know that a loong time ago I had to educate a major racing organization about the dangers of using a simple kill switch if the engine was still running.

ps If you can, the real way to boost from another car is to let it charge your battery for 10-15 minutes. Disconnect. Then start yours. Few will bother.

pps the power from a Honda generator like the 2000i is pretty clean but some of the cheap ones leave a lot to be desired.

jacko15 05-09-2013 11:58 AM

Re: 2014 3.6 Check Engine Light Help
 
All this being said, I guess the average new vehicle owner is S.O.L. when it comes to the electrical systems in their vehicle. For mine and my wife's vehicles, I've replaced the battery every four years. That's about the useful life of one in my climate. I've always hated finding a dead battery, and it's usually in the dead of winter, so to me, it's budgeted as regular maintenance. With roadside assistance, a dead battery will be a dealer service problem for me.

BobsWK2 05-09-2013 07:31 PM

Re: 2014 3.6 Check Engine Light Help
 
Quote:

Originally Posted by padgett (Post 820169)
I just carry a jump box. AAA trucks usually have one. Nice clean power and not a big enough battery to load the alternator. $35 or less on sale & fits in the rear seat footwell with the seats folded.

That said, a battery acts like a really big capacitor and is a major part of the power filtering system of a car.

Back in the day, alternators could not put out enough power at idle to be a problem but in the last few decades, 100-200A alternators have been the norm. I have replaced a 94A peak (about 40A at idle) alternator with a CS-144 in my little RV that can put out over 100A at idle.

Also once upon a time the hot side of the alternator and jumper cables attached directly to the battery so there was little chance of a resistive/bad connection. Today particularly with the relocation of the battery, there is liable to be a splice/connection in the middle. If loose, wellll.

BTW there is a note in the jumping procedures not to use anything greater than 12v but does not go into the potential for surges/spikes.

Do know that a loong time ago I had to educate a major racing organization about the dangers of using a simple kill switch if the engine was still running.

ps If you can, the real way to boost from another car is to let it charge your battery for 10-15 minutes. Disconnect. Then start yours. Few will bother.

pps the power from a Honda generator like the 2000i is pretty clean but some of the cheap ones leave a lot to be desired.

Boy I can remember when you ordered a car from GM with air conditioning, it came with a 55 amp alternator. I think there was even a heavy duty 70 amp alternator available as an option. But the electrical demands of todays cars requires a lot of alternator output.


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