There have been several posts about the trunk lid lock so I thought I would put up an explanation of how it works on MY07 TDi. Normal operation of the trunk lock is important for the roof to work. The roof system uses the open/closed lock switch as feedback.
The lid lock is in 2 parts and without removing trim or covers, it can be hard to figure out what's going on. Both parts have mechanical and electrical operation. Understanding how the lock works is essential if power or control is lost.
The trunk lid contains the business end of the lock. As you look into an open lid you can see the fork and an internal rotating 'V' claw. This assembly has a three wire connection. The lock is locked mechanically without power. As you close the lid, the claw engages with the roller pillar you see in the second bottom part of the lock which I will call the 'keep' and pushes the rotating claw around where a spring then holds it in the closed or lock position. This rotating 'V' claw is free moving, you can close it very easily with a screwdriver and then not be able to shut the lid! This is what can happen if the claw gets closed and is 'out of sync'. No electrical power is required to close the claw! The claw is only released by electrical power to a motor which releases a mechanical latch and the claw then rotates open, allowing the lid to pull out of the keep. That's why the EOS cannot close its lid from the console. It can only close the lid during roof operation using hydraulic rams. Two wires in this upper lock assembly are used to power the release latch and a third wire is a signal wire to determine if the 'V' claw is open or closed. The assembly has a crappy length of plastic (the square you can see underneath on the right). When pushed up, this mechanically releases the lock latch to open the claw.
The second part of the lock is the 'keep' which isn't just the simple bar you can see. The keep bar can be moved down and up by a motor - the 'whirring' sound you hear as the trunk lid is closed or opened. IT HAS NOTHING TO DO WITH THE ACTUAL LOCKING. Its purpose is to pull down the trunk lid on to the two black sprung buffer stops and to compress the trunk lid into its seal.
This is the sequence for locking: As the trunk lid is lowered when the keep bar is at its highest point, it slides into the slot and the 'V' claw rotates to the locked position. The locked closed switch then activates the pull down motor and the keep bar drops until limit or over current and stops. The trunk lid is now compressed on to its seals and hopefully no water gets in!
The trunk lid can only be opened in two ways - electronically or mechanically. The normal electronic open sequence is to activate the lid motor to release the locked claw causing the lid to pop up from pressure on the seal, then the keep bar is lifted (whirrs) to the high position ready to receive the lid when it is next closed. The flip up VW badge does no more than operate a switch. If there is a power or control problem, it won't release the lock.
Ignoring the tensioning feature, the locking and unlocking is purely mechanical with electronic motor assistance only for unlocking. An emergency cable with red pull ring is run to just behind the ski panel which opens the lock if there is a total power fail or control problems. This is where something as important as emergency release design went a bit wrong. The best place to operate the release is actually in the business end of the lock in the trunk lid. However, in VW's scheme of things, they ran their emergency release wire to a lever on the right of the keep assembly mounted on the fixed rear panel. They then used a crappy plastic conecting rod in the lid assembly, which ends as the small square you see to the right of the claw. Therefore, their emergency trunk release relies upon the cable working, the push up lever on the back panel working and not getting misaligned and their short flimsy plastic push rod not breaking or its location peg falling out.
Everybody with an EOS should occasionally remove the ski panel with the trunk lid closed, pull the emergency trunk release and make sure it works!!
.
The lid lock is in 2 parts and without removing trim or covers, it can be hard to figure out what's going on. Both parts have mechanical and electrical operation. Understanding how the lock works is essential if power or control is lost.
The trunk lid contains the business end of the lock. As you look into an open lid you can see the fork and an internal rotating 'V' claw. This assembly has a three wire connection. The lock is locked mechanically without power. As you close the lid, the claw engages with the roller pillar you see in the second bottom part of the lock which I will call the 'keep' and pushes the rotating claw around where a spring then holds it in the closed or lock position. This rotating 'V' claw is free moving, you can close it very easily with a screwdriver and then not be able to shut the lid! This is what can happen if the claw gets closed and is 'out of sync'. No electrical power is required to close the claw! The claw is only released by electrical power to a motor which releases a mechanical latch and the claw then rotates open, allowing the lid to pull out of the keep. That's why the EOS cannot close its lid from the console. It can only close the lid during roof operation using hydraulic rams. Two wires in this upper lock assembly are used to power the release latch and a third wire is a signal wire to determine if the 'V' claw is open or closed. The assembly has a crappy length of plastic (the square you can see underneath on the right). When pushed up, this mechanically releases the lock latch to open the claw.
The second part of the lock is the 'keep' which isn't just the simple bar you can see. The keep bar can be moved down and up by a motor - the 'whirring' sound you hear as the trunk lid is closed or opened. IT HAS NOTHING TO DO WITH THE ACTUAL LOCKING. Its purpose is to pull down the trunk lid on to the two black sprung buffer stops and to compress the trunk lid into its seal.
This is the sequence for locking: As the trunk lid is lowered when the keep bar is at its highest point, it slides into the slot and the 'V' claw rotates to the locked position. The locked closed switch then activates the pull down motor and the keep bar drops until limit or over current and stops. The trunk lid is now compressed on to its seals and hopefully no water gets in!
The trunk lid can only be opened in two ways - electronically or mechanically. The normal electronic open sequence is to activate the lid motor to release the locked claw causing the lid to pop up from pressure on the seal, then the keep bar is lifted (whirrs) to the high position ready to receive the lid when it is next closed. The flip up VW badge does no more than operate a switch. If there is a power or control problem, it won't release the lock.
Ignoring the tensioning feature, the locking and unlocking is purely mechanical with electronic motor assistance only for unlocking. An emergency cable with red pull ring is run to just behind the ski panel which opens the lock if there is a total power fail or control problems. This is where something as important as emergency release design went a bit wrong. The best place to operate the release is actually in the business end of the lock in the trunk lid. However, in VW's scheme of things, they ran their emergency release wire to a lever on the right of the keep assembly mounted on the fixed rear panel. They then used a crappy plastic conecting rod in the lid assembly, which ends as the small square you see to the right of the claw. Therefore, their emergency trunk release relies upon the cable working, the push up lever on the back panel working and not getting misaligned and their short flimsy plastic push rod not breaking or its location peg falling out.
Everybody with an EOS should occasionally remove the ski panel with the trunk lid closed, pull the emergency trunk release and make sure it works!!
.
