If on your Nissan Almera G15 The brake lights have stopped working, the problem requires an immediate solution - this is not only a traffic violation, but also a direct threat to road safety. Owners of this model often encounter a similar malfunction, and there may be several reasons: from a banal lamp burnout to serious problems with the electrical system or the body control unit (BCM).

In this article we will look at all the possible reasons why brake lights are on Almera G15 (in bodies N17 And N18) may not light up, and we will also give step-by-step instructions for diagnosis and repair. We will pay special attention to the typical “weak points” of this model - for example, oxidation of contacts in the fuse box or operating features multi-pin connector rear lights. You will learn how to check the circuit without special tools, which fuses are responsible for the brake lights, and when to contact an auto electrician.

1. Primary diagnosis: what to check first

Before disassembling half the car, start with basic checks. In 70% of cases, the problem lies in small things that can be fixed in 10 minutes.

The first thing to do is visually inspect the rear lights with the brake pedal pressed. If both brake lights do not light up, but the side lights or turn signals do, the problem is most likely in a common circuit element (fuse, switch, wiring). If only one light does not work, the lamp, socket or local wiring is to blame.

  • 💡 Brake lamps: Even if they look intact, the filament may have burned out. On Almera G15 lamps are used P21/5W (double-strand). Test them with a multimeter or replace them with ones that are known to work.
  • 🔌 Cartridges and contacts: Often oxidize or burn. The cartridges on this model are plastic and can crack from overheating.
  • ⚡ Fuse F37 (10A): Responsible for brake lights. Located in the fuse box under the steering wheel (see diagram below).
  • 🚗 Brake light switch: Located under the brake pedal. Its contacts may stick or break.

If after checking these elements the problem remains, proceed to diagnosing the wiring and control unit. But first, make sure that the contacts of the lights receive voltage when the pedal is pressed - for this you will need a multimeter or a test lamp.

📊 Where do you start diagnosing broken brake lights?
  • I'll check the lamps
  • I'll check the fuses
  • I'll ring the switch under the pedal
  • I'll inspect the wiring

2. Fuses and relays: where to look and how to check

On Nissan Almera G15 The fuse is responsible for the brake lights F37 face value 10A, which is in interior fuse box (under the steering column, to the left of the pedals). To get to it:

  1. Open the unit cover by pulling it towards you.
  2. Find the fuse F37 (there is a diagram on the cover).
  3. Remove it with tweezers and check visually - the burnt thread will be visible.
  4. If the fuse is intact, but the brake lights do not work, check the voltage at its contacts with the brake pedal depressed (there should be 12V).

If the fuse blows again after replacement, there is short circuit. Most often it occurs in the wiring harness under the rear bumper or in the light itself due to moisture ingress. Also check the relay K3 (brake light relay), although on this model it rarely fails.

element Location Symptoms of a problem
Fuse F37 (10A) Cabin block, position F37 Burns out, thread breaks, body melts
Relay K3 Cabin block, position K3 Clicks when you press the pedal, but the lamps do not light up
Brake light switch Under the brake pedal The lamps are constantly on or do not respond to the pedal
Body Control Module (BCM) Under the dashboard Several circuits do not work simultaneously

Important: on Almera G15 after 2016 release, the brake light fuse can be combined with the clearance circuit (F20). Check the diagram on the block cover!

3. Brake light switch: how to check and replace

The brake light switch (or “frog”) is one of the most common causes of brake light failure. On Almera G15 it is located above the brake pedal and is attached to the bracket with two bolts. To check it:

  1. Remove the plastic trim under the steering wheel (snap off the clips).
  2. Find the switch - it has two-pin connector with wires (usually white and black).
  3. Disconnect the connector and test the contacts with a multimeter in the “testing” mode: when the pedal is pressed, the circuit should close.
  4. If the switch does not work, try adjusting its position (tighten the fastening nut) or replace it with a new one (part number: 25430-JM00A).

Typical signs of a broken switch:

  • 🚦 The brake lights are constantly on (even without pressing the pedal).
  • 🚗 The lamps light up only when the pedal is pressed firmly.
  • ⚡ There is an error on the dashboard ABS or ESP (on models with these systems).
💡

If the switch is OK, but the brake lights are not working, check the continuity of the wires from the switch to the fuse box. The insulation around the pedal assembly often wears out.

4. Wiring problems: where to look for an open or short circuit

Brake light wiring Almera G15 passes through several critical zones where it can grind or oxidize:

  • 🔌 Tail light connectors: often oxidize due to moisture. Remove the lights and check the contacts (especially pin 1 And pin 2 — they are responsible for the brake lights).
  • 🚗 Harness under the rear bumper: Wires may rub against metal or rust. Pay attention to the area left rear light - Dirt often accumulates there.
  • 🔋 Positive wire from fuse: goes through the relay box to the switch. Check it for a break (there should be 12V with the ignition on).
  • 📡 Ground wire: On this model, the brake light ground is mounted to the body under the rear seat. Oxidation here causes the lamps to flicker.

To check the wiring:

  1. Disconnect the rear light connector.
  2. Turn on the ignition and press the brake pedal.
  3. Call the contact with a multimeter +12V on the light connector (should appear when the pedal is pressed).
  4. If there is no voltage, look for an open circuit between the switch and the light.
How to test wiring without a multimeter?

You can use a test lamp (12V) with wires. Connect one end to the positive of the battery, the other - touch the contacts of the flashlight connector one by one while pressing the pedal. If the lamp lights up, the circuit is working.

If the problem is in the ground, clean the place where the wire is attached to the body (clean the metal to a shine) and apply contact lubricant (For example, Liqui Moly Kupfer-Spray).

5. Body Control Module (BCM): When the Electronics are to Blame

If all mechanical components are in good working order, but the brake lights still do not work, the problem may lie in body control module (BCM). On Almera G15 it is located under the dashboard on the driver's side and is responsible for controlling the lighting, including the brake lights.

Symptoms of a faulty BCM:

  • 🚨 Several circuits do not work at the same time (for example, brake lights + instrument lighting).
  • 🔄 The lamps light up randomly without pressing the pedal.
  • 💻 Errors related to CAN bus.

It is not recommended to repair the BCM yourself - it is a complex device with soldered contacts. However, you can try:

  1. Reset errors by disconnecting the battery for 10 minutes.
  2. Ring the power supply of the unit (contact +12V And mass).
  3. Check the fuse F1 (10A) in the BCM block (it is responsible for powering the microcircuits).

If the unit is faulty, it will have to be reflashed or replaced. For Almera G15 Suitable blocks with article numbers:

  • 285B0-JM00A (until 2017)
  • 285B0-JM00B (after 2017)
💡

Before replacing the BCM, be sure to check its part number with the original one! Blocks from different years of release may have different software.

6. Common mistakes during repairs and how to avoid them

Many owners Almera G15 make the same mistakes when diagnosing brake lights, which leads to unnecessary expenses or aggravation of the problem. That's what can't do:

⚠️ Attention: Never replace brake light bulbs with LED ones without checking compatibility! On this model BCM may not recognize low LED resistance, causing the lamps to flicker or not light up at all. Use only lamps with CAN-Bus adapter.
  • 🔧 Ignore contact oxidation: Even if the lamp is new, oxidized sockets or connectors will negate the effort. Always clean your contacts WD-40 or fine sandpaper.
  • ⚡ Install a fuse of a higher rating: This may cause a fire! If F37 (10A) burns out, look for the reason, and do not increase the amperes.
  • 🚗 Do not check the switch after adjustment: If the frog is adjusted too high, the brake lights will stay on constantly, draining the battery.
  • 💡 Buy cheap lamps: They often have a low-quality filament that burns out after a week. Take the original (Nissan 37110-JM00A) or proven analogues (Osram, Philips).

Another common mistake is do not check the operation of brake lights after repair in the dark. During the day, red lights may be difficult to see, and you may not notice that they are bright or flickering.

Turn off the ignition and remove the negative terminal of the battery|Check the new socket for cracks|Apply dielectric grease to the lamp contacts|Make sure the lamp O-ring is intact-->

7. Frequently asked questions (FAQ)

Why do the brake lights not light up on my Almera G15, but the parking lights work?

This is a typical sign blown fuse F37 (10A) or faulty brake light switch. Dimensions and brake lights are powered from different circuits: dimensions go through a fuse F20, and the feet - through F37. Start by checking the fuse, then test the switch under the pedal.

Is it possible to drive if the brake lights don't work?

No! According to Traffic rules clause 2.3.1, operating a vehicle with faulty brake lights is prohibited. In addition to a fine (500–1000 rubles), you risk becoming the culprit of an accident, since other drivers will not be able to react to braking in time. As a last resort, use alarm when stopping.

The brake lights are constantly on, even without pressing the pedal. What's the matter?

This is 100% a problem with brake light switch (contacts stuck) or it incorrect adjustment. Unscrew the switch (above the brake pedal) and check if the rod returns to its original position. If not, replace the switch (part no. 25430-JM00A).

After replacing the bulbs, the brake lights come on, but dimly. Why?

Most likely the problem is bad contact or oxidation of ground wire. Check:

  • Clean contacts in the lamp socket and connector.
  • Ground integrity (black wire, attached to the body under the rear seat).
  • The voltage on the lamp when the pedal is pressed (should be 12V, if less, look for losses in the wiring).
Is it possible to flash the BCM myself if the brake lights are not working because of it?

No, for firmware BCM Requires specialized equipment (e.g. Consult-III+) and knowledge of protocols CAN. Incorrect firmware can completely damage the unit. Contact an authorized dealer or a trusted car service with an electrical diagnostician.