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Discussion Starter · #1 ·
First thanks for any valid information. Second, please only reply if you know for sure what the issue is or how to correct the issue.

When placing the vehicle from reverse to drive, from the park position, I hear a noticeable thump and the engine goes into limp mode (3rd gear) and sets the check engine light.

I can fool the system by placing the vehicle into reverse, then placing it into park, then placing the vehicle into drive. No limp mode and no check engine lights.

The check engine lights go everywhere from invalid VIN to transmission pressure issues and CAN A/CAN B problems. Like I said, I can fool it and get no lights whatsoever.

Again, thanks.
 

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Did you change anything or have a service done?

I would check the pan filter and check your battery.
 

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2006 Commander Limited, 5.7 Hemi QD2
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Please make a signature with your Commander details. (year, model trim, engine, 4wd system, etc.) It is nice for us know what your Commander has in it so we can better help you.

The front end clunk is most likely the front differential bushings, and possible that is shaking some wires loose causing the other errors. Just a thought.
 

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First thanks for any valid information. Second, please only reply if you know for sure what the issue is or how to correct the issue.

When placing the vehicle from reverse to drive, from the park position, I hear a noticeable thump and the engine goes into limp mode (3rd gear) and sets the check engine light.

I can fool the system by placing the vehicle into reverse, then placing it into park, then placing the vehicle into drive. No limp mode and no check engine lights.

The check engine lights go everywhere from invalid VIN to transmission pressure issues and CAN A/CAN B problems. Like I said, I can fool it and get no lights whatsoever.

Again, thanks.
Sounds to me like you have bad shift control module.
 

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Discussion Starter · #5 ·
Did you change anything or have a service done?

I would check the pan filter and check your battery.
I have conducted a transmission fluid, filter service and replaced the battery. No changes. Thanks
 

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Discussion Starter · #6 ·
Please make a signature with your Commander details. (year, model trim, engine, 4wd system, etc.) It is nice for us know what your Commander has in it so we can better help you.

The front end clunk is most likely the front differential bushings, and possible that is shaking some wires loose causing the other errors. Just a thought.
Thanks. All connections cleaned with electronic parts cleaner and verified clean and tight, shiny and bright.
 

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Discussion Starter · #7 ·
Sounds to me like you have bad shift control module.
Thanks. That is where this journey is taking me however, if the module was bad, how can I trick it every time?
 

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Thanks. That is where this journey is taking me however, if the module was bad, how can I trick it every time?
@illonegraywolf ;

Just because you can trick it into working again for short periods of time, does not mean it's good.

It could simply be an intermittent problem, which is common with old, worn electronic components.

I didn't see any mention of this in your initial post, so I'll ask;

Have you tried the key dance - or, do you have an OBD-II scanner to see if you can pull any Diagnostic Trouble Codes?

I would think there should be a DTC generated, by the issue you're having - which should always be the first thing you look for, when you're having any kind of a suspected mechanical, electrical or electronic sensor/module problem.
 

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Discussion Starter · #9 ·
@illonegraywolf ;

Just because you can trick it into working again for short periods of time, does not mean it's good.

It could simply be an intermittent problem, which is common with old, worn electronic components.

I didn't see any mention of this in your initial post, so I'll ask;

Have you tried the key dance - or, do you have an OBD-II scanner to see if you can pull any Diagnostic Trouble Codes?

I would think there should be a DTC generated, by the issue you're having - which should always be the first thing you look for, when you're having any kind of a suspected mechanical, electrical or electronic sensor/module problem.
Thanks. Not intermittent. I can make it happen or make it not happen. Highly unusual. I am seriously believing a TCM.
 

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Thanks. Not intermittent. I can make it happen or make it not happen. Highly unusual. I am seriously believing a TCM.
Either way, its indicative of a faulty TCM or, a faulty shift control module in my opinion.

F.Y.I. The shift control module is just to the right of the steering column inside/underneath the dashboard.

The TCM is built into the PCM on the V-8's.

You also never answered my question.

Did you check for generated DTC's with an OBD-II scanner, or, by performing the key dance?

Also, some good reference information here;

 

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Discussion Starter · #11 ·
Either way, its indicative of a faulty TCM or, a faulty shift control module in my opinion.

F.Y.I. The shift control module is just to the right of the steering column inside/underneath the dashboard.

The TCM is built into the PCM on the V-8's.

You also never answered my question.

Did you check for generated DTC's with an OBD-II scanner, or, by performing the key dance?

Also, some good reference information here;

I too am almost 100% sure it's the TCM as well and I have pulled the codes however, like I said, I can bypass them. The DTC's are misleading and with the CAN B or CAN A issues which try and lead me down a rabbit hole. I watch an awesome video from Pine Hollow Diagnostics who followed the rabbit holes and everything he found led to the TCM. Just don't like the 300.00 price tag.
 

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I have conducted a transmission fluid, filter service and replaced the battery. No changes. Thanks
So battery ruled out.

Did you perform the filter change yourself or have it done? The pan filter seal is hard to get right.

Did you do fluid drain and refill or flush? How is the fluid level?
 

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Discussion Starter · #13 ·
So battery ruled out.

Did you perform the filter change yourself or have it done? The pan filter seal is hard to get right.

Did you do fluid drain and refill or flush? How is the fluid level?
Correct on new battery. Filter change done and redone to cooler filter seating issues question. Complete new fluid fill on both changes. Levels good. No leaks.
 
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