Join Date: Mar 2008
Location: New England '13 XTS Platinum
The rear deck lid should be hard to lift. That's a good thing. You're fighting hydraulics when the hydraulic bypass valve is in the normally closed position.
Just so we’re speaking the same language, the Rear Tonneau resides on the underside of the Rear Deck Lid when the Folding Top is closed. The three flaps in the front of the trunk compartment make up the Front Tonneau.
When you say the Rear (or Front?) Tonneau Switch was loose, do you mean the square sensor (potentiometer?) If loose, and re-tightened, that can throw the Rear Tonneau out of cal. The only way to restore the new Closed/Open values is to have a Re-Learn performed with a Tech 2.
Your windows should lower as soon as the system verifies the interlocks are in the proper configuration: Valet Switch off, luggage barrier in place, transmission in Park. If any of them aren't configured properly when the Folding Top Control Switch is pressed, a message will appear on the DIC.
Check out the condition of the connectors on the Folding Top Control Module. Make sure they're seated properly, then physically inspect the front face of both sets of connectors.
Ensure the engine is off before de-mating/mating these connectors.
While you're poking around in there, cash in some free insurance and verify your compartment drain line isn't obstructed or a high watermark exists inside the compartment, indicating previous flooding. When inspecting the drain line, yYou should be able to see the pavement through it.
If the compartment floods out from rain runoff through the trunk seals (very, very common) it usually takes the Suspension Control Module with it. This is expensive on a good day.
Sometimes, the TOP NOT SECURE message is caused by a faulty or misaligned windshield header switch.
If you have a meter, it's easy to check. The switch is located in the right side pin receiver of the windshield. You have to remove the two Torx screws to pull the assembly out and access the switch and it's short harness. Pull gently on the harness to expose the connectors. Ensure there isn't anything funky going on there.
Before de-mating, tie a 24" piece of string to the end of the harness opposite the switch. If it lands back in the windshield header with no way to retrieve it, you'll have a larger job to deal with. Once de-mated, check for continuity when the switch is depressed. If the switch is good, make sure it's centered in the pin receiver so it's depressed when the pin engages the receiver.
This is a great example of how a Tech 2 can save a lot of time troubleshooting - especially on the problematic 2004-2005 folding tops. If the FTC were working and taking inputs from the different sensors it uses to figure out Folding Top component positions, you could tell if a switch was stuck or a sensor was bad. If you plan to keep your XLR indefinitely, I can't recommend having access to a Tech 2 enough.
From what I can tell, the FTC is acknowledging the press of the Folding Top Control switch, getting a position error for a component and won't initiate even the window-lowering sequence, --which is first on it's list of Do's when the top is supposed to stow in the trunk. This is similar to a Valet Switch or Luggage Barrier Switch message which stops the operation in it's tracks, as soon as the Folding Top Control switch is depressed. (A high-level Interrupt for all you fellow geeks out there.)
If after doing the checks I've written up and nothing is obvious, we'll need to roll up our sleeves and look deeper.
At this point,