'04 Coupe Liftgate lock failure

[Swimdad]

Ive tried to search this topic as my 04 coupe's liftgate is locked and will not release. Can I open manually to repair the vacuum line
Thanks in advance
Swimdad

[spensley]

It's a vacuum line so if it's broken (leaking) there should be no vacuum so it should not be locked. Try unplugging the battery for half an hour, reconnect and retry to unlock it.

[Swimdad]

Thank you, I'll give it a try but why disconnect the battery. What will that do.

[onehundred80]

Originally Posted by spensley

It's a vacuum line so if it's broken (leaking) there should be no vacuum so it should not be locked. Try unplugging the battery for half an hour, reconnect and retry to unlock it.

The locking/unlocking system is not a normally open or normally closed system. Air pressure is used to open the locks and vacuum is used to lock them. A broken line will effectively keep the locks engaged or open depending on their position when the failure occurred.
If any clicking sound is coming from the latch area itself when the key fob lock and unlock buttons are pressed then I think that the lock mechanism itself has failed. No sound from this area would indicate to me that the air/vacuum hose has broken, in this case a hissing sound may be heard, possibly at the top of the hatch on the drivers side.

The following is from the shop manual page 8Q-47

VEHICLE LOCKING/UNLOCKING

To unlock, the Body Control Module is actuated by the SKREEM. The Body Control Module then sends the signal
to the Central Locking Pump/Security System Module (CLP/SSM) via the Controller Area Network (CAN) Bus. The
CLP/SSM pump motor starts running and supplies air pressure. The door lock actuators are pressurized. When a
pressure threshold is reached in the system, the pump is switched off by an internal pressure switch. The pressure
in the system is then released by the CLP/SSM and the unlocking operation is completed. The locking procedure is
accomplished in a fashion opposite to the unlocking operation. However, the next time the remote control button is
pressed, the CLP/SSM is also actuated by connecting it to ground by the second control lead on the SKREEM. The
direction of rotation for the CLP/SSM pump motor is reversed, thereby providing the vacuum required to lock. In
order to avoid unlocking the vehicle unintentionally, the vehicle is relocked by the CLP/SSM via the SKREEM.
Relocking is accomplished after unlocking with the remote control when: a door is not opened within 40 seconds,
the key is not inserted into the ignition lock, the interior power door lock switch is not actuated, only the liftgate is
opened after unlocking. The CLP/SSM reads the signals (door contacts, trunk lid, interior power door lock switch)

and actuates the power door lock actuators. The vehicle security alarm is also activated by the relocking function.

[Swimdad]

)nehundredeighty,
Thank for the reply. Last year the dealer fixed the leaking/broken airline when the liftgate was unlocked. This time they have to find a way to get to with it being lock. This is a PIA since it has been less that 1l months since the last repair.

[sonoronos]

Originally Posted by Swimdad

)nehundredeighty,
Thank for the reply. Last year the dealer fixed the leaking/broken airline when the liftgate was unlocked. This time they have to find a way to get to with it being lock. This is a PIA since it has been less that 1l months since the last repair.

If you can, do the repair yourself with polyurethane pneumatics line instead of that ridiculous, cheezy yellow vinyl crap.

The entire pneumatics industry now uses polyurethane - I don't know why MB still uses rigid, brittle plastic. The line should last longer than your car and never fail again.

[Swimdad]

Is there anyway to manually open the latch so I can access the area to do the repair or do I need to climb into the trunk through the driver or passenger door make the repair before the latch will open.

[maxcichon]

If a dealer repaired it once, less than 12 months ago, it should be under a separate 12 month warranty. At least GM and Ford will stand behind their work this way.

Check the paperwork from the repair. It might state this.

Originally Posted by Swimdad

)nehundredeighty,
Thank for the reply. Last year the dealer fixed the leaking/broken airline when the liftgate was unlocked. This time they have to find a way to get to with it being lock. This is a PIA since it has been less that 1l months since the last repair.

[onehundred80]

Originally Posted by Swimdad

Is there anyway to manually open the latch so I can access the area to do the repair or do I need to climb into the trunk through the driver or passenger door make the repair before the latch will open.

What was the outcome of this incident, it is nice to know the answer to questions.

[dekoene]

I'm having the same problem over here... can't open the trunk anymore. Is there a way to open the trunk when the pneumatic line is broken?
Unplug the battery...??

[Swimdad]

Well, I ended up needing to have my local Chrysler dealer redo their repair. Despite the fact they initially did the repair 11 months ago it still cost me $90 this since I was just out of warranty. This time the tech went to Grangers and replaced the cheap *** line with a high quality vacuum line. Life is good again. I can complain about this dealer, they replaced both headlamp assemblies because the tech noticed a pencil eraser size haze spot in the corner of each. They replaced my '04 model fog lamps with the new design since one of the plastic chrome bulb covers came loose. They replaced my door speakers when i started hearing a slight speaker crack static every now and then despite their inability to reproduce the defect.

[onehundred80]

Originally Posted by Swimdad

Well, I ended up needing to have my local Chrysler dealer redo their repair. Despite the fact they initially did the repair 11 months ago it still cost me $90 this since I was just out of warranty. This time the tech went to Grangers and replaced the cheap *** line with a high quality vacuum line. Life is good again. I can complain about this dealer, they replaced both headlamp assemblies because the tech noticed a pencil eraser size haze spot in the corner of each. They replaced my '04 model fog lamps with the new design since one of the plastic chrome bulb covers came loose. They replaced my door speakers when i started hearing a slight speaker crack static every now and then despite their inability to reproduce the defect.

Do you know how they got at the latch?

[Swimdad]

The same way I would have, climbed over the seats and pulled the liner away, used a make shift jig to by-pass the defective line to open the trunk.... Too hot / to cramped for me...worth the $90 bucks

[onehundred80]

Originally Posted by Swimdad

The same way I would have, climbed over the seats and pulled the liner away, used a make shift jig to by-pass the defective line to open the trunk.... Too hot / to cramped for me...worth the $90 bucks

Thats what we wanted to hear and as we expected.
Not a job for overweight mechanics though.

[Punkin]

My wifes '04 just failed also. All doors and gas door locked! What a pain in the caboose. I got the gas door open by pulling off the inside panels but there is no way I'm gonna get stuck in the boot by climbing into the back. Any ides how else to get the back hatch open?

[newCrossfire]

this happend to my xfire this weekened. thankfully it got stuck in the open position. so i found the break in the vacuum line it was right at the hinge where the wires feed into the hatch. there is a flexible grommet. i took it apart and it exposeed where the line had broken. i decided to take a crack at fixing it myself sooooo i went down to PepBoys and in there vaccum line section they had a small rubber tube for connecting lines. i just connected the piece i purchased between the broken line and VOILA!!! it works like charm! best part is i only payed 2 BUCKS for the vacuum connection piece i bought. i only wish i wouldve taken pics but i was excited to get it done.