[cj2391]

2015 trailhawk, does not have factory towing option.

I acquired a factory receiver from a wrecked trailhawk. We used a curt 56208 wiring harness. After installing the hitch and wiring the powered Liftgate will not open from any of the interior buttons or from the hatch button, if you use the key fob the lights do flash twice but the hatch does not respond. No warning lights or errors in screen. Does dispaly that the hatch is open if it is open.

If you manually open the hatch using the release in the door and close it the lock motor does engage

These are the troubleshooting steps we have tried so far...

We disconnected the t connectors that went behind each rear light and unplugged the hot wire from the battery completely removing the trailer lights connection from the system and the problem remains.

Have checked the fuse (f50) and it is good.

Have left fues out for longer than 30 seconds and locked the doors with the button on the door handle (forum solution that worked for some)

I have disconnected battery for a decent period of time.

Nothing has changed the way the door responds. Help, I am running out of things to try!

 

[sanghill]

Check under the floorboard in the trunk and look of water.
Recall R27/NHTSA 15V-393 should apply to your vehicle. All it does is add a shield over the PLM which is in the spare tire area forward of the license plate.
The contacts in the connectors may be corroded. Check for water exposure to the connectors. Apparently there are 2.
There are computer modules all over the place down there, might as well check all of them.
You will need plastic trim stick C-4755, equal to remove the liftgate scuff plate.
If you can print the instructions for R27 that has all the details, all 23 pages.
Even if R27 is complete you could still have the corrosion problem because it occurred before the shield was installed.
If you need R27 your Jeep dealer should do it for free.

I don't have a clue about your tow wiring harness.

 

[cj2391]

I don't have a clue about your tow wiring harness.

Thank you, I am looking into that recall now. The trailer lights actually work fine, just that the issue with the gate started after we connected that harness.

 

[Gary Kline]

Thank you, I am looking into that recall now. The trailer lights actually work fine, just that the issue with the gate started after we connected that harness.

Does it work with the car started? (running) The power Lift Gate module (PLGM) has a low-voltage cutoff built in to prevent battery run-down. The electrical system voltage must be between a min. and max. specification for it to work. Is it possible the battery is low from the trailer light hookup/testing etc.?

 

[Gary Kline]

Thank you, I am looking into that recall now. The trailer lights actually work fine, just that the issue with the gate started after we connected that harness.

To confirm, you've unhooked the Curtis harness and the power liftgate is still not working even when everything is fully re-connected as "stock", correct?

 

[Gary Kline]

Thank you, I am looking into that recall now. The trailer lights actually work fine, just that the issue with the gate started after we connected that harness.

A couple other thoughts....

1. The tail light circuitry all connects back to the BCM. There's no tie-in to the Power Lift Gate Module (PLGM) or its components so at face value, it wouldn't appear as though the Curtis box itself isn't causing any problem. (ps. I did the similar thing you're doing to my 2014 TH - added a hitch and wiring since mine didn't come with it. As I recall, as long as you ran the positive (+) power wire to the battery directly and the ground wire to any metal point in the back, you should be fine. The connections to the right and left taillights are "triggers" only. The Curtis box isn't drawing power from the taillight circuitry.)

2. Double check the the ground from the PLGM (black wire - see red arrow in schematic below) didn't get pulled off on the PLGM when removing the trim/working with wires in the back. As @sanghill noted, there's a recall for water getting into the PLGM area. If you feel wetness near it, good chance that's it. If the ground connection seems corroded or not solid in any way, try re-grounding it elsewhere and see if it works.

3. Last but not least (longshot), the power lift gate is powered only on the left side, the side you probably worked on (the right side of the powered lift gate is just a standard gas cartridge. Only the left side is powered.) The power lifter wiring comes through the body at the top and connects to a harness that's in the area of the left taillight where you were working on. Any chance the connector came loose? Perhaps unplug and re-plug it? (see two pix below)

Good luck!

 

[cj2391]

Thanks you guys for all the assistance. Sadly I found the issue and it was 100 percent stupidity😂. When originally planning to run the 12v line through the plastic inside my father drilled a couple holes.... One of them was directly into the top of the Liftgate controller module.... Hopefully a local salvage yard has one and we can get this resolved tomorrow. Once again. Thank you for the assistance, the info that was given in such a short time period was amazing.

 

[Gary Kline]

Thanks you guys for all the assistance. Sadly I found the issue and it was 100 percent stupidity😂. When originally planning to run the 12v line through the plastic inside my father drilled a couple holes.... One of them was directly into the top of the Liftgate controller module.... Hopefully a local salvage yard has one and we can get this resolved tomorrow. Once again. Thank you for the assistance, the info that was given in such a short time period was amazing. View attachment 222275
View attachment 222274

Hmmm.... well.... think of the bright side....

1. The case looks nice and dry, guess you don't have to worry about the water recall issue 😂 😂 😂
2. At least it wasn't the Fuel Sending Unit 😱 💥🔥

 

[Gary Kline]

Confirmed issue

 

[cj2391]

Hmmm.... well.... think of the bright side....

1. The case looks nice and dry, guess you don't have to worry about the water recall issue 😂 😂 😂
2. At least it wasn't the Fuel Sending Unit 😱 💥🔥

Ha, Yeah definitely could have been much worse. And after 42 years I finally get to say something was my dad's fault, He can fix about anything so it's very rare.

 

[Gary Kline]

Ha, Yeah definitely could have been much worse. And after 42 years I finally get to say something was my dad's fault, He can fix about anything so it's very rare.

When I was in my late teens/early 20's, I was sure my parents didn't know anything. Now I realize everything I know came from them and they were really smart after all 🙏

 

[sanghill]

Give your father a this set: Drill Stop Set, 7 Piece