Liftgate issues, replaced actuator still nothing

[Tngal18]

2015 Yukon Denail XL...My situation seems different. Liftgate completely stopped working after intermittently operating fine. I replaced the actuator and pass side shock. Still nothing. Every once in a while it will open, but never closes on its own. Yes, dial is set correctly and button is on. Here's my key clue. When you shut it manually, it does pull it shut. So I know the automatic latch is working. However, the interior lights will not go off. Which tells me the vehicle isn't being told the door is closed. So, what switch am i missing? What else can cause the liftgate to not work? The glass will not pop open either and when you push the buttons on fob , tail lights just flash. Not even a click in the liftgate.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

When you say 'actuator', can you be more specific on what this is?

 

[Tngal18]

2015 yukon Denali XL....My situation seems different. Liftgate completely stopped working after intermittently operating fine. I replaced the actuator and pass side shock. Still nothing. Every once in a while it will open, but never closes on its own. Yes, dial is set correctly and button is on. Here's my key clue. When you shut it manually, it does pull it shut. So I know the automatic latch is working. However, the interior lights will not go off. Which tells me the vehicle isn't being told the door is closed. So, what switch am i missing? What else can cause the liftgate to not work? The glass will not pop open either and when you push the buttons on fob , tail lights just flash. Not even a click in

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

I cannot personally help you with your question; however, other members on this Forum that are much more knowledgeable than me will chime in.

When you say 'actuator', can you be more specific on what this is?

Liftgate actuator which consists of both shocks and wiring harness

 

[Joseph Garcia]

Liftgate actuator which consists of both shocks and wiring harness

OK. 'Actuator' is both shocks (and installed on the correct sides) and the wiring harness. Nothing changed in the lift gate lift rod or the motor?

 

[Tngal18]

OK. 'Actuator' is both shocks (and installed on the correct sides) and the wiring harness. Nothing changed in the lift gate lift rod or the motor?

No.

 

[Joseph Garcia]

Do you have a bi-directional scan tool? If so, you can try to perform the operation, and the scan tool will troubleshoot the operation, and most likely give you some usable information.

 

[Tngal18]

I do not

 

[Tngal18]

Now it will close on its own, just not raise with power. Can raise manually. What gives??? I can hear the fuse box clicking. It is the big square fuse 1191 in the fuse panel in rear cargo compartment

 

[zbad55]

I replaced the liftgate rod on my 2016, the drivers side is the power actuator, and has the plug from the harness, the passenger side is passive. If you have replaced both of these not sure what the problem would be.

 

[markni12301]

If you don't have a local auto parts chain store with loaner tools, https://www.borrowmyscantool.com/
could expedite resolution.

 

[Tngal18]

I replaced the liftgate rod on my 2016, the drivers side is the power actuator, and has the plug from the harness, the passenger side is passive. If you have replaced both of these not sure what the problem would be.

Yep. Replaced both.

 

[Tngal18]

Will close on its own . But will not open with power now. Have to open manually. When you try to open taillights just flash. Also glass will not open at all

 

[Doubeleive]

Will close on its own . But will not open with power now. Have to open manually. When you try to open taillights just flash. Also glass will not open at all

how is the rear wiper operation? I haven't messed with a k2 rear hatch but in previous generations if the rear wiper is not parked properly then the glass will not open.
but if the wiper is up top on these then it might not matter but it could maybe have something to do with it.

 

[Tngal18]

how is the rear wiper operation? I haven't messed with a k2 rear hatch but in previous generations if the rear wiper is not parked properly then the glass will not open.
but if the wiper is up top on these then it might not matter but it could maybe have something to do with it.

Yea, wiper is up top. I just don't understand why the liftgate will close but not open automatically

 

[Doubeleive]

Yea, wiper is up top. I just don't understand why the liftgate will close but not open automatically

how about the backup sensors? any issue there, have you tested them for proper operation? if not you can test them with a helper or put it in reverse and apply the parking brake so it will not move and then place your hand or a object over each sensor one at a time and listen for a beep from each sensor. also might not have anything to do with anything.
does yours have the bottom foot sensor? so if you swipe your foot under it the hatch opens? if so maybe that is dirty or something? possibly causing an error
just spit balling here, but if there is no other issue it could maybe be one of the parts already replaced is not working correctly or some form of calibration is needed.
a gds2 tool would maybe reveal the issue

 

[Tngal18]

how about the backup sensors? any issue there, have you tested them for proper operation? if not you can test them with a helper or put it in reverse and apply the parking brake so it will not move and then place your hand or a object over each sensor one at a time and listen for a beep from each sensor. also might not have anything to do with anything.
does yours have the bottom foot sensor? so if you swipe your foot under it the hatch opens? if so maybe that is dirty or something? possibly causing an error
just spit balling here, but if there is no other issue it could maybe be one of the parts already replaced is not working correctly or some form of calibration is needed.
a gds2 tool would maybe reveal the issue

Not the sensors

 

[Doubeleive]

Not the sensors

then either the motor is not working properly or the assist gas cylinder is not working properly or something is binding up so it hits max resistance.
the hatch is designed to stop and reverse if it hits something, this calculates into initial lifting also if it sense's too much weight it gives up. i.e. lift motor not having enough torque/voltage/too much lift resistance
low voltage can cause it to not operate properly.
going to take some troubleshooting, you can try a finger assist and see if it goes up with a little help
check battery voltage and be sure you have 12v+.
with a good tool you can command it open/close and any errors may show up, that kind of error will not show up in the DIC

 

[Tngal18]

New info.

Called the dealership and found out it had a code. B396a

Looks like it is the module and not what I replaced . Has anyone had to replace this?

 

[trottida]

I'm not sure of the 2015+ models but on the 2007-14 models the liftgate glass not opening may have to do with the wiper motor transmission not sensing that the wiper is in park position. It will only allow the liftgate glass to open when in park position. I'm not sure if it is the same on the 2015+ as the wiper is at the top of the glass rather than the bottom but it might be worth investigating. Perhaps their is a sensor in the glass latch mechanism that will not allow the liftgate to open if it senses the glass is open. I'd try to resolve the glass not opening issue first and it may kill 2 birds with one stone.