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2008 ESV AWD, 2010 ESV AWD, 2015 GMC Sierra 2500HD D/A 2008 GMC Savana Conversion Van, 2012 CTS-V
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Discussion Starter · #1 ·
Hi,

I have a 2010 Escalade ESV that I did extensive work on after a collision. After putting all of the pieces back together again, I found the rear hatch lock / unlock, rear gate touch sensor, key fob gate open, and manual button on the ceiling up front will not open the liftgate. In the process of putting it back together again, my helper lost my Liftgate control module, so I ordered a replacement from GM Parts Direct. The rear glass opens, and there is 12V to the rear latching mechanism. All fuses are good, and if I click the gate lift button on the fob, I can hear the relay click under the hood and the lights flash. I hooked my Tech 2 up to it, and the liftgate control module cannot be found. I don't have a software license for the Tech 2, so I cannot program modules. Has anyone had to swap out these modules before? Does it need to be programmed for the rear lift gate and latch to work? I would appreciate the help!

Thanks!

Nick
 

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2018 CTS V-Sport
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4 Posts
Hi Nick,
I am familiar with this thru my work and can answer some questions regarding the Power Liftgate Module. This one is older than what I typically deal with but I think I can still help.

Is this the original module from the vehicle? If so is there any damage to is from the accident? is the PCB burned or and connector pins bent?
Can you access this module and verify all 3 plugs are connected?
No comm to this module would typically mean either GMLAN or Power/GND is not connected. The middle connector is the one that supplies power and there are 2 separate 12V feeds (pins 3 & 4, pin 6 is gnd if i remember correctly)
Can you check for DTC's?

Thanks.
Jim
 

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2008 ESV AWD, 2010 ESV AWD, 2015 GMC Sierra 2500HD D/A 2008 GMC Savana Conversion Van, 2012 CTS-V
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55 Posts
Discussion Starter · #3 ·
Good morning. I didn't see any trounle codes other than a VIN error on the left blind zone module, but that is because I replaced the door. The liftgate module is not from the truck. I had to order another one from an online seller of GM parts. My thought was the module needed to be programmed but I wanted confirmation from someone with more knowledge than I have in replacing these modules. I probed at the lock connector, and saw 2 separate 12 V readings and 1 ground as well when I checked.

Thanks,

Nick
 

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2018 CTS V-Sport
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4 Posts
I wouldn't expect a need to reprogram the PLGM unless is was shipped to you without any software installed. This is Magna's 1st/2nd generation (current production is 5th gen) liftgate module for Common Arch (pre-Global A). GMT900
Does anything function for the gate? Does the latch Cinch or Release? You said it does not open, will it power close?
The PLGM does not control the liftglass.
Signals that will prevent operation of the gate include
GMLAN signals: PRNDL & vehicle speed, Lock/unlock, Crank, low voltage
Internal signals: Pinch strips, Latch Inputs, Gear Motor inputs, Latch Mech Fail, Mode Sw Disable.
Also some of these older systems vehicles require 2 ignition cycles before a new module will operate.
 

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2008 ESV AWD, 2010 ESV AWD, 2015 GMC Sierra 2500HD D/A 2008 GMC Savana Conversion Van, 2012 CTS-V
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55 Posts
Discussion Starter · #5 ·
Yes, the glass opens but nothing else on the gate functions, including closing. I inspected the wiring harness in the liftgate and found some chafed wires that go to the gate latch actuator. I repaired them and still don't have any response from the liftgate module. It is possible the module was shipped with no software. When I press the gate unlock on my remote, I get the liftgate relay to click and the rear lights flash, and then nothing else happens. I will check the Tech 2 for any abnormalities in the GMLAN parameters when I get home tonight. I wish I had a spare liftgate module lying around!
 

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2008 ESV AWD, 2010 ESV AWD, 2015 GMC Sierra 2500HD D/A 2008 GMC Savana Conversion Van, 2012 CTS-V
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55 Posts
Discussion Starter · #6 ·
I wouldn't expect a need to reprogram the PLGM unless is was shipped to you without any software installed. This is Magna's 1st/2nd generation (current production is 5th gen) liftgate module for Common Arch (pre-Global A). GMT900
Does anything function for the gate? Does the latch Cinch or Release? You said it does not open, will it power close?
The PLGM does not control the liftglass.
Signals that will prevent operation of the gate include
GMLAN signals: PRNDL & vehicle speed, Lock/unlock, Crank, low voltage
Internal signals: Pinch strips, Latch Inputs, Gear Motor inputs, Latch Mech Fail, Mode Sw Disable.
Also some of these older systems vehicles require 2 ignition cycles before a new module will operate.
I know this is a late reply, but I just got around to looking at it again. Here are the things I know. The ground you told me to look at is good. Both positive wires you told me to check had no power. I went under the hood and probed for power to the Liftgate Control Module, and Fuse 71 had power. Fuse 44 did no, but I wasn't sure if this was hot only at actuation. I see the hot wires correspond to circuits 1242 and 840
 

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2008 ESV AWD, 2010 ESV AWD, 2015 GMC Sierra 2500HD D/A 2008 GMC Savana Conversion Van, 2012 CTS-V
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55 Posts
Discussion Starter · #7 ·
And there were no abnormalities in the GMLAN parameters you mentioned, and there are no DTCs of any sort. I had a history code for a heated O2 sensor that I replaced. I cleared it and then no codes, and the liftgate module obviously didn't magically fix itself. At this point I am thinking of checking continuity to the two positive wires up in the fuse boxes. Do you have any other suggestions?
 
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