<em>Nissan Tiida</em> trunk lock: why it won’t open and how to fix it yourself

Nissan Tiida is a popular compact car, but even it has problems with the trunk lock over time. Either the door does not open with the key, then the central lock jams, or the mechanism creaks. If you are faced with a similar situation, do not rush to go to the service: many faults can be fixed with your own hands.

In this article we will analyze all typical trunk lock failures on Tiida (including restyled versions of 2007–2016), we will give step-by-step instructions for repair and replacement, and also tell you how to avoid repeated problems. The material is based on the experience of owners and mechanics, so there are no general phrases here - only specific solutions.

Signs of a faulty trunk lock

The first signal that something is wrong with the lock is unusual sounds when opening or closing. Creaking, knocking or crunching indicate mechanical wear. But there are other symptoms:

• 🔑 The key turns with difficulty or does not turn at all.
• 🚗 The central locking does not work on the trunk (while the doors open).
• 🔓 The trunk door can only be opened from the inside or requires physical effort.
• 💡 The open trunk indicator on the dashboard lights up, although it is closed.
• 🔧 The lock is stuck in one position (will not lock or unlock).

If you notice at least one of these signs, you cannot ignore the problem. On Nissan Tiida with an electric trunk lock, a malfunction can lead to a short circuit in the central locking circuit, which will entail costly repairs to the control unit.

Most often problems arise due to:

• 🔧 Wear of the mechanism (rust, dirt, lack of lubrication).
• 🔌 Electric drive malfunctions (on models with central locking).
• 🔑 Breakage of the lock or key cylinder.
• 🚗 Body deformation after an accident or careless opening.

Diagnostics: how to determine the cause of a breakdown

Before disassembling the lock, you need to understand what exactly the problem is. Let's start with the simplest checks:

1. Check the key. It may have become bent or worn out. Try opening the trunk with the spare key. If it works, the problem is with the key, not the lock.
2. Examine the lock cylinder. Shine a flashlight: if rust or dirt is visible inside, the mechanism needs to be cleaned and lubricated.
3. Check the central locking. Press the button on the key fob or in the cabin - if all the doors open except the trunk, the problem is in the actuator or wiring.
4. Try opening the trunk from inside. On Tiida there is a lever next to the driver's seat (to the right of the pedals). If it works, but the key does not, the cylinder or rod is to blame.

If the trunk does not open in any way, you will have to remove the interior trim and manually disconnect the lock rod. To do this:

1. Remove the plastic trunk sill trim (it is secured with clips).
2. Unscrew the screws holding the casing (usually 4-6 pieces).
3. Carefully bend the trim and find the rod that goes from the lock to the opening mechanism.
4. Pull the rod manually to open the trunk.

Mechanical trunk lock repair

If the problem is mechanical (the key turns hard, creaks, jams), most likely the lock needs to be cleaned and lubricated. Here are the step-by-step instructions:

1. Remove the lock trim. It is attached to two self-tapping screws (under the decorative trim) and latches. Carefully pry it off with a flathead screwdriver.
2. Remove the lock cylinder. To do this, you need to unscrew the locking screw (it is located on the side) and pull the cylinder out.
3. Clean the mechanism. Use WD-40 or kerosene to remove rust and dirt. Wipe the parts with a clean cloth.
4. Lubricate the lock. Best fit silicone grease (does not attract dust). Apply it to all moving parts, including springs and latches.
5. Check springs and rods. If they are bent or loose, they will need to be replaced (see table below for part numbers).

After assembly, check the operation of the lock several times. If the key is still difficult to turn, the cylinder may be worn out and will need to be replaced.

How to check the lock rod?

If the rod is bent or rusted, it may block the mechanism. To check its condition, remove the trunk trim and pull the rod manually. It should move smoothly, without jamming. If the rod is damaged, replace it (part no. 72501-4M000 for Tiida 2007–2012).

Detail	Article number (OEM)	Approximate price, ₽	Notes
Trunk lock cylinder	36420-4M000	1 200–1 800	Suitable for Tiida 2007–2016
Lock rod	72501-4M000	300–500	May vary in length depending on year of manufacture
Lock spring	72505-4M000	150–250	Sold complete with traction
Central locking actuator	28500-4M000	2 500–3 500	Electric models only

Replacing the trunk lock cylinder

If cleaning does not help and the key still does not turn, the cylinder needs to be replaced. This can be done without removing the entire lock:

1. Remove the lock trim (as described above).
2. Unscrew the locking screw of the cylinder (it is located on the side and can be hidden by a rubber cap).
3. Insert the key into the cylinder and turn it to the "open" position. This will unlock the mechanism.
4. Pull the larva towards you - it should come out of the nest.
5. Install a new cylinder (part number 36420-4M000) and secure it with the locking screw.

Important: When purchasing a new cylinder, make sure that it fits your key. On Nissan Tiida cylinders with different perforations are used - if you buy the wrong one, the key will not fit. It is better to take the original or proven analogues from Denso or Mitsuba.

Repair of electric lock (central locking)

On Tiida with electric trunk lock (optional) Power Door Lock) problems are often related to the actuator or wiring. Symptoms:

• 🔌 The trunk does not open with the key fob, but it opens with the key.
• 🔊 A click is heard, but the lock does not work.
• 🚨 There is an error on the tidy Door Ajar (even when the trunk is closed).

For diagnostics:

1. Check the fuse F30 (10A) in the block under the steering wheel - it is responsible for the central locking.
2. Check the wiring from the control unit to the actuator (use a multimeter).
3. Remove the trunk trim and check whether voltage is supplied to the actuator when you press the key fob (there should be 12V).

If the actuator does not work, it must be replaced:

1. Disconnect the battery terminal.
2. Remove the trunk trim and find the actuator (black plastic case with a wire).
3. Disconnect the power connector and unscrew the two mounting bolts.
4. Install a new actuator (part number 28500-4M000) and connect the wires.

⚠️ Attention: If after replacing the actuator the trunk opens spontaneously, check the central locking control unit (BCM). On Tiida it often fails due to moisture ingress. In this case, you need a diagnostic scanner to clear the errors.

Adjusting the trunk lock

If the trunk does not close tightly or opens while driving, the problem may be latch adjustment. On Tiida The lock is attached to the body with two bolts, which become loose over time.

To adjust the lock:

1. Open the trunk and find two bolts securing the lock (they are hidden under rubber plugs).
2. Loosen the bolts with a wrench 10.
3. Close the trunk and check how the latch fits into the mate. It should fit tightly, without play.
4. Adjust the position of the lock, moving it in the desired direction, and tighten the bolts.

If after adjustment the trunk still does not close, check counter part of the lock (it is attached to the trunk lid). It may be bent or worn. In this case, it needs to be replaced (part no. 72510-4M000).

How to check the trunk seal?

Sometimes the trunk does not close well due to a worn seal. Check it around the entire perimeter - if the rubber is cracked or comes off, replace the seal (part number 80510-4M000). This will also help prevent water from leaking into the trunk.

Prevention: how to extend the life of a trunk lock

To avoid problems with the lock, just follow simple rules:

• 🔧 Lubricate the lock silicone grease every 6 months (especially before winter).
• 🚿 Wash the trunk not only outside, but also inside - dirt and salt from the roads get into the mechanism.
• 🔑 Don't use force when opening - if the key does not turn, it is better to disassemble and clean the lock.
• 🔌 Check the wiring for oxidation (especially if the car is often parked in the rain).
• 🚗 Don't slam the trunk - this deforms the latch and the body.

If you frequently transport heavy loads, install gas struts (article 73401-4M000) - they will reduce the load on the lock when opening.

⚠️ Attention: On Nissan Tiida 2013–2016 model years, the plastic rod in the trunk locks sometimes breaks. If you hear a cracking sound when opening, replace it immediately - otherwise the lock will jam completely.

FAQ: Frequently asked questions about the trunk lock Nissan Tiida

Is it possible to open the trunk if the key inside the lock is broken?

Yes, but carefully. Do not try to pull out the fragment with tweezers - this will damage the larva. It is better to remove the trunk trim from the interior and manually pull the rod. If a piece of the key sticks out, you can try to pull it out with pliers, after spraying WD-40.

Why doesn't central locking work only on the trunk?

Most likely the problem is in the actuator or a broken wire. Check the fuse F30, check the wiring from the control unit to the actuator. If there is power, but the lock does not work, replace the actuator.

How much does it cost to replace a trunk lock at a service center?

The cost depends on the type of breakdown:

• Replacing the larva - from 1,500 to 2,500 rubles (including labor).
• Actuator replacement - from 3,000 to 4,500 rubles.
• Complete replacement of the lock - from 5,000 to 7,000 rubles.

Do-it-yourself repairs will cost 2–3 times less.

What is the best lubricant to lubricate the lock?

Use silicone grease (For example, Liqui Moly Silicone-Fett) or graphite lubricant. Do not use WD-40 as a permanent lubricant - it is washed out and does not protect against corrosion.

Is it possible to install an alarm with automatic trunk opening?

Yes, but this will require some modification to the wiring. On Tiida with central locking, you can connect an additional actuator to the alarm system (for example, StarLine or Pandora). It is better to entrust this to professionals, since you need to solder the relay correctly.