Encountered an error B1404 on your dashboard Nissan Almera Classic? This code is one of the most common in a car’s self-diagnosis system, but its appearance often causes panic among owners. In practice, the error is associated with a fault in the circuit Throttle Position Sensor (TPS) or problems in the operation of the electronic control unit (ECU). In this article we will look in detail at what exactly it means. code B1404 for Almera Classic with QG15DE/QG16DE/QG18DE engines, how to correctly diagnose it and what steps to take to eliminate it - from a simple check of contacts to replacing the sensor.

It is important to understand that ignoring this error can lead to unstable engine operation, increased fuel consumption, or even the ECU going into emergency mode. Moreover, in 60% of cases the problem is solved without expensive repairs - just competent diagnostics and minimal skills in working with a multimeter are enough. If you are not confident in your abilities, it is better to contact specialists, but many operations can be performed independently, saving on a service center.

What does error B1404 mean on Nissan Almera Classic

Code B1404 in the self-diagnosis system Nissan stands for "Throttle Position Sensor (TPS) circuit malfunction". This sensor is responsible for transmitting data about the current throttle opening angle to the ECU, which, based on them, adjusts the fuel supply, ignition timing and other engine operating parameters.

On Almera Classic (including restyled versions 2006–2012) the error is manifested by the following symptoms:

  • 🔥 Check Engine light on on the dashboard (sometimes flashing).
  • 🚗 Dips during acceleration or rough idle.
  • ⚡ Increased speed (1500–2000 rpm) without pressing the gas pedal.
  • 🛢️ Increased fuel consumption (10–15% above normal).
  • 🔧 ECU switches to emergency mode (power limitation).

Unlike errors on the lambda probe (for example, P0130) or ignition coils, B1404 directly connected to the mechanical part of the throttle assembly and its electrical circuit. Most often it occurs due to:

  • 🔌 Oxidation or broken contacts in the sensor connector.
  • 📉 Wear of the resistive layer inside TPS (typical for runs over 150 thousand km).
  • 🔋 Short circuit or a break in the wiring between the sensor and the ECU.
  • 🖥️ Failure in the ECU firmware (rare, but occurs after incorrect chip tuning).
📊 What symptom of error B1404 have you encountered?
  • Check Engine light on
  • Jerks during acceleration
  • Increased speed
  • Increased fuel consumption
  • Other

How to Test the Throttle Position Sensor (TPS)

Sensor diagnostics TPS on Nissan Almera Classic begins with a visual inspection and a test with a multimeter. You will need:

  • 🔧 Screwdriver with a Phillips bit (for removing the throttle assembly).
  • 📊 Multimeter (voltmeter and ohmmeter mode).
  • 🧴 WD-40 or contact lubricant (for cleaning contacts).

Step 1: Sensor localization

The TPS is installed on the throttle body (on the side or top, depending on the year of manufacture). On Almera Classic with engine QG16DE it is secured with two screws using a Phillips screwdriver. Disconnect the sensor connector and inspect it for oxidation or damage.

Step 2: Check the supply voltage

Connect a multimeter in voltmeter mode (range 20V) to the contacts +5V (usually red wire) and mass (black wire) on the sensor connector. When the ignition is on, the voltage should be 4.8–5.2 V. Deviations indicate problems in the wiring or ECU.

Step 3: Signal Wire Test

Connect the multimeter probes to the contacts signal (usually a gray or green wire) and mass. When the damper is closed, the voltage should be 0.3–0.7 V, when fully open - 4.0–4.7 V. Smoothly opening the damper manually, monitor the voltage changes: surges or dips indicate a sensor malfunction.

Disconnect the sensor connector and inspect the contacts|Check the supply voltage (4.8–5.2 V)|Measure the signal on a closed damper (0.3–0.7 V)|Check the smoothness of the signal change when the damper is opened|Clean the connector contacts (if necessary)-->

Common causes of error B1404 and solutions

Error B1404 rarely occurs on its own - it is always preceded by specific malfunctions. Below we will look at the most common reasons and solutions for Nissan Almera Classic.

Reason Symptoms Solution Repair cost (RUB)
Oxidation of TPS connector contacts Periodic appearance of the error, especially in wet weather Cleaning contacts with WD-40 or CRC 2-26, dielectric grease treatment 0–200
Wear of the resistive layer of the sensor Jerks during acceleration, unstable idle speed Replacing the TPS sensor (part number: 22680-4M000 or 22680-4M005) 1 500–3 000
Open or short circuit in wiring Permanent error B1404, other codes are possible (for example, P0120) Wire testing, repair or replacement of harness 500–2 000
Throttle valve contamination Floating speed, the error appears after a long drive Cleaning the throttle with a product LIQUI MOLY Pro-Line Drosselklappen-Reiniger 300–800
ECU firmware failure The error appears after chip tuning or disconnecting the battery Reset adaptations via CONSULT-III or flashing 2 000–5 000

Important nuance: if after replacing the TPS sensor there is an error B1404 remains, must be completed reset throttle adaptations. On Almera Classic this is done through a diagnostic scanner (for example, Launch CReader) or by disconnecting the battery for 10–15 minutes. Without a reset, the ECU may continue to generate a false error.

How to reset throttle adaptations without a scanner?

1. Disconnect the negative terminal of the battery for 10-15 minutes.

2. Reconnect the terminal and turn on the ignition (without starting the engine) for 30 seconds.

3. Turn off the car, then start the engine and let it idle for 3-5 minutes.

4. Take a test drive with smooth acceleration to 40–50 km/h.

If the error was related to adaptations, it will disappear after 2-3 startup cycles.

Step-by-step instructions for replacing the TPS sensor

If the diagnostics show a faulty sensor, it must be replaced. For Nissan Almera Classic original sensors with article numbers are suitable 22680-4M000 (until 2008) and 22680-4M005 (after 2008), as well as analogues from Hitachi, Denso or Standard Motor Products. The average price is 1,500–3,000 rubles.

Tools:

  • 🔧 Phillips screwdriver (PH2).
  • 🔨 10 mm socket wrench (for removing the throttle assembly, if necessary).
  • 🧴 Carburetor or throttle cleaner.

Replacement steps:

  1. Disconnect the negative terminal of the battery.
  2. Remove the air duct leading to the throttle assembly (unscrew the clamps).
  3. Disconnect the TPS sensor connector by pressing the latch.
  4. Unscrew the two screws securing the sensor and remove it.
  5. Install the new sensor by aligning the grooves. Tighten the screws to torque 1.5–2.0 Nm (do not overtighten!).
  6. Connect the connector and reassemble everything in reverse order.
  7. Reset adaptations (see spoiler above).
💡

Before installing a new sensor, clean the seat on the throttle assembly from dirt and old grease. This will prevent debris from getting inside the mechanism and extend the life of the TPS.

Frequent mistakes during diagnostics and repairs

Many owners Nissan Almera Classic make typical mistakes that lead to reoccurrence B1404 or new problems. That's what can't do:

⚠️ Attention! Never use to clean sensor contacts. TPS abrasive materials (sandpaper, metal brushes). This breaks the protective coating and accelerates corrosion. Use only plastic scrapers or specialized sprays.

Error 1: Ignoring wiring check

If the sensor is working, but the error remains, the wiring may be to blame. Ring the chain from TPS to the ECU (contacts A10 And A20 on the ECU connector) for open or short circuit. Pay special attention to the area near the exhaust manifold - wires there often melt from high temperatures.

Error 2. Installing a non-original sensor without adaptation

Cheap analogues (for example, from no-name manufacturers) may have a nonlinear characteristic, which is why the ECU will generate an error even with a working sensor. After replacement necessarily reset adaptations!

Error 3. Cleaning the throttle without removing the damper

If you clean the throttle body without removing it, dirt and cleaner residue may get into the intake manifold or onto the mass air flow sensor (MAF). This will lead to new errors, for example, P0100 or P0171.

💡

Before replacing the TPS, always check the integrity of the resistive layer of the old sensor. If there are dark stripes or scratches on it, this is evidence of mechanical wear, and replacement is required.

When is professional diagnostics required?

In most cases the error B1404 You can fix it yourself, but there are situations when you can’t do without the help of a car service:

  • 🔧 The error appears immediately after replacing the sensor (there may be a problem with the ECU).
  • 📊 On the scanner in addition to B1404 there are other codes associated with MAF, lambda probe or ignition.
  • ⚡ The engine is extremely unstable (troits, stalls), which may indicate problems with the wiring or ground.
  • 🖥️ The error occurred after chip tuning or flashing the ECU.

In these cases it will be necessary in-depth diagnostics using professional equipment such as:

  • Launch X431 or Bosch KTS — to analyze parameters in real time.
  • Oscilloscope - to check the signal TPS for interference.
  • A multimeter with a continuity function - to search for breaks in the harness.

The average cost of diagnostics in the service is 1,000–2,500 rubles. If the problem is in the ECU, it may need to be repaired or replaced (from 5,000 rubles).

Preventing error B1404

To minimize the risk of recurrence B1404, follow these guidelines:

  • 🔧 Clean the throttle body every 30–40 thousand km (use products without aggressive solvents).
  • 🛢️ Monitor fuel quality — bad gasoline accelerates wear of sensors.
  • 🔌 Check your contacts periodically on connectors TPS And MAF (especially before winter).
  • 🚗 Avoid sudden pressure on the gas pedal when the engine is cold, this increases the load on the throttle valve.

Expert advice: if you often drive on dusty roads, install zero resistance filter (For example, K&N) and change the air filter more often. This will reduce the load on the throttle assembly and extend life TPS.

FAQ: Frequently asked questions about error B1404

Is it possible to drive with error B1404?

Short term - yes, but not recommended. Driving for a long time with a faulty TPS leads to:

  • Increased fuel consumption (up to +20%).
  • Accelerated wear of the catalyst.
  • Risk of engine overheating due to incorrect fuel mixture.

If the error appears on the way, get to the repair site without sudden acceleration.

How can you tell the difference between a faulty TPS and a throttle body problem?

Take the test:

  1. Disconnect the connector TPS with the engine running.
  2. If the speed has stabilized, the sensor is to blame.
  3. If the speed still fluctuates, there is a problem in the damper mechanics (contamination, play).
Will the TPS sensor from Nissan Note or Tiida work?

No! Despite their external similarity, the sensors have different characteristics. For Almera Classic Only original art. is suitable. 22680-4M000/4M005 or certified analogues with the same connector block.

What should I do if the error remains after replacing the TPS?

Follow these steps:

  1. Check that the connector is connected correctly (the contacts must fit tightly).
  2. Reset throttle adaptations (see spoiler above).
  3. Check the wiring from the sensor to the ECU.
  4. If the error remains, check the ECU for other codes.
Can the TPS sensor be repaired?

Theoretically, yes, but not practical. The resistive layer inside the sensor wears unevenly, and even after repair (for example, replacing the graphite coating) TPS will produce incorrect data. The cost of repair is comparable to the price of a new sensor.