W202/W210 trunk won't open? Trunk lock A2107500784
“Trunk won't open” or “central locking doesn't lock the trunk” – these searches come up regularly for the W202 and W210. On both model series, the trunk lock is more than a simple latch: the lock cylinder doubles as a push button for opening, a vacuum element locks the lid via the pneumatic central locking, and a microswitch reports the status to the vehicle. After 25 to 30 years, each of these functions can fail. This guide shows how to narrow down the cause, what to watch for regarding the design, and which lock fits your car.
Genuine trunk lock A 210 750 07 84 with lock cylinder, vacuum element and microswitch – the photos show the actual part.
Symptoms
| Symptom | Likely cause |
|---|---|
| Trunk lid can no longer be opened via the lock cylinder (push button) | Lock mechanism or rotary latch stiff or worn |
| The trunk lid can no longer be locked or unlocked with the key | Lock cylinder or driver in the lock worn |
| Trunk lid does not stay reliably closed | Rotary latch no longer engages the striker on the rear panel cleanly |
| Doors lock via central locking, only the trunk lid does not | Vacuum element on the lock leaking or hose connection detached |
| No door and no lid locks via central locking any more | Not a case for the trunk lock – the cause lies in the central supply of the central locking system |
| Key sticks at the driver's door, the trunk works | Door lock instead of trunk lock – checking steps in the guide W124 door lock defective? |
Causes
The lock sits on the inside of the trunk lid, centered at the level of the handle strip, with the cylinder and its rubber collar protruding outward. It is fastened with two screws, with a gasket in between. This is exactly where splash water, road salt and years of operation take their toll: old grease gums up, metal parts develop patina, the lock cylinder wears out. In addition, the plastic of the housing and the latch guide becomes brittle with age and can break.
On the vacuum element, the diaphragm ages; if it leaks, the pneumatic central locking no longer locks the lid. Because the cylinder, vacuum element and microswitch are all built into the lock, replacing the complete unit is often the direct route.
Testing it yourself
- Try the spare key: If the lock works with a different key, the key is worn, not the lock.
- Clean and lubricate the cylinder: Apply lock spray to the cylinder and operate it several times. If it becomes smooth, gumming was the cause.
- Central locking cross-check: If the doors lock but the trunk lid does not, the fault is in the vacuum element or its hose at the lock. If nothing locks at all, look first at the central supply of the central locking.
- Visual inspection from inside: With the lid open, check the housing for cracks and breakouts, the rotary latch for smooth movement and the hose connection on the vacuum element.
- Determine the design: Before buying, compare the vacuum element and switch with the photos – after the facelift, an angled vacuum element is fitted.
There is a separate guide for the predecessor model series: W123 trunk won't open? Check the trunk lock – the W123 lock is a different part and does not fit the W202 or W210.
Solution
If cleaning and lubricating do not help, replacing it with a genuine lock is the right solution. We offer the Genuine trunk lock A 210 750 07 84 (A2107500784) with lock cylinder, vacuum element and key – genuine parts, not aftermarket. Four units in different conditions are currently available, price 129,00 € to 179,00 €:
- 179,00 € (two units): with microswitch (3-pin connector) and 1 key, housing without breakage, signs of use.
- 139,00 €: with microswitch and 1 key, housing broken out at the side next to the rotary latch.
- 129,00 €: without microswitch, with 1 duplicate key on a JMA blank, a piece of plastic has broken out at the latch guide.
Scope of delivery: Lock with cylinder and vacuum element (with microswitch depending on the listing) and 1 key, without hose and screws. The key fits this cylinder, not the door and ignition locks of your car.
Important – not to be confused with: Does not fit after the facelift (different design with vacuum element A 208 800 03 75 and switch A 208 820 10 10), not for W210 with remote trunk lid release and not for the T-model wagons S202/S210. If in doubt, send us your VIN (chassis number) via the contact form.
With microswitch + original key
A 210 750 07 84 · Housing without breakage, fine scratches
179,00 €
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With microswitch + key
A 210 750 07 84 · Housing without breakage, slight patina
179,00 €
View offer →
With microswitch + key
A 210 750 07 84 · Housing broken out at the side (hole)
139,00 €
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Without microswitch, with duplicate key
A 210 750 07 84 · Plastic broken out at latch guide
129,00 €
View offer →You will find more locks in the collection Locks & door handles.
Compatible vehicles
| Model series | Models |
|---|---|
| C-Class W202 sedan (1993 until the facelift approx. 1997) | all engine variants, with pneumatic central locking |
| E-Class W210 sedan (1995 until the facelift 1999) | all engine variants, without remote trunk lid release |
| Does not fit | W202/W210 after the facelift, W210 with remote trunk lid release, T-model wagons S202 and S210 |
FAQ
Does the trunk lock A 210 750 07 84 also fit after the facelift?
No. From the facelift on (W202 approx. 1997, W210 1999), a different design with an angled vacuum element A 208 800 03 75 and switch A 208 820 10 10 is fitted. The lock described here is the early design before the facelift.
Does the lock fit the T-model wagon S202 or S210?
No. The T-model wagons S202 and S210 have a tailgate with its own lock. The trunk lock A 210 750 07 84 is intended only for the W202 and W210 sedans.
My W210 has a remote trunk lid release – does the lock fit?
No. W210 with remote trunk lid release already had the later design before the facelift. If in doubt, compare your old part with the product photos or send us your VIN (chassis number).
Does the supplied key fit my doors and the ignition lock?
No. The key fits the lock cylinder of this lock, not the door and ignition locks of your car. If you want a single key for everything, you can keep using your own lock cylinder, provided it is still in good condition.
Which previous numbers does A 210 750 07 84 supersede?
A 202 750 00 84, A 202 750 04 84 as well as A 210 750 04 84, 05 84 and 06 84 are considered predecessors of the lock. The lock cylinder carries A 202 750 07 91, A 202 750 02 91 or A 210 750 02 91, the vacuum element A 202 800 20 75 and the switch A 202 820 51 10.
KFZTeile-Thot is a specialist business for tested and refurbished Mercedes parts with its own test benches and has over 1,000 positive eBay reviews. Not sure whether the lock fits your C- or E-Class? Call us: +49 179 8991069 (Mon–Fri 8 am–6 pm) – or use our contact form.