What we've got here is failure to communicate

Wranglerfix

Wranglerfix

TJ Enthusiast
Supporting Vendor
Lifetime Supporting Member
Joined
May 2, 2019
Messages
991
Location
Hollywood, Fl
A customer has an 06 manual that will not communicate through the obd2 port without the Jeep being started. I had him unplug the fuel rail, replace ignition switch and still no com when switch is on. It communicates fine while running. Here is the weird part...The obd2 port works fine with his old pcm. I sent him a second pcm that I triple checked in my Jeep and it communicated perfectly in mine.

A similar situation happened about a month ago with a customer's speedometer. It would work with his old pcm and not with mine. He finally changed the speed sensor and everything is running as it should.

Thanks in advance,

Mark

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Are there any other electrical abnormalities ?
I would start by checking the small fuses in the fuse block behind the glove compartment.
Pin 4 and 16 should always have power when measured between them.
Pin 16 is the battery positive and 4 is the chassis ground.
 
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From customer…

Ground on 4&5 battery on 16 nothing on 7 and I don’t have pin in 14 I have pins in 2,4,5,7,9,12,15,16
 
I realize the owner replaced the Ignition Switch, but I would check the Ignition Switch wiring harness for signs of overheating.

I believe the reason why Terminals 6 and 14 are missing; they are for CAN BUS communications that started in the '07 JKs...

Please keep us advised as to how the problem is resolved....
 
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