P2135 on Nissan Almera Classic: why the “Check” is on and how to fix the problem

Error code P2135 on Nissan Almera Classic (body N16) is one of the most common problems faced by owners of this car. It signals a discrepancy between signals from Throttle Position Sensor (TPS) And accelerator pedal position (APP) sensor. As a result, the ECU records an error, the “Check” lights up, and the engine can go into emergency mode with limited power.

Unlike many other codes, P2135 often occurs not due to mechanical failure, but due to failures in the electrical circuit or software errors in the control unit. This makes its diagnosis more difficult: without a scanner and knowledge of the sensor connection diagram, it can be difficult to identify the cause. In this article, we will analyze all possible sources of the problem - from banal oxidation of contacts to a malfunction of the ECU itself, and also give step-by-step instructions for troubleshooting the problem.

What does error P2135 mean on Nissan Almera Classic

Code P2135 stands for «Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation». Translated, this means that the ECU has detected a discrepancy between the signals of two sensors:

• 🔹 Sensor A - main throttle position sensor (TPS), installed on the throttle assembly itself.
• 🔹 Sensor B — accelerator pedal position sensor (APP), which records the driver's press.

In normal mode, both sensors should produce synchronous signals: when you press the gas pedal, the throttle opens, and their readings coincide. If the ECU sees a difference of more than 10-15% (the threshold depends on the firmware), it fixes the error P2135 and can:

• 🚨 Activate “Check” on the dashboard.
• 🔧 Limit engine speed (up to 2000-3000 rpm).
• ⚡ Put the engine into emergency mode with a fixed throttle opening.

On Almera Classic with engines QG15DE And QG18DE The error often appears when you sharply press the gas or when coasting. In some cases, the “Check” lights up periodically and goes out after the engine is restarted - this is a typical sign of a problem with the contacts or a “floating” sensor signal.

The main causes of error P2135

In practice 90% of cases errors P2135 on Nissan Almera Classic associated with one of five reasons. They can be divided into two groups: electric (problems with wiring, contacts, sensors) and mechanical (throttle, damper wear). Below is a complete list with decreasing frequency of occurrence:

Reason	Frequency (%)	Signs
Oxidation of sensor connector contacts	35%	The error appears after rain or washing and disappears periodically
Throttle Position Sensor (TPS) malfunction	25%	The “check” light is constantly on, the speed “floats” at idle
Wiring problems (open, short)	20%	The error appears during vibration (for example, on bumps)
Worn or dirty throttle valve	15%	The engine stalls, the speed “freezes” when releasing the gas
ECU firmware failure	5%	The error appears after disconnecting the battery or flashing the firmware

Particular attention should be paid connector contacts. On Almera Classic they often oxidize due to moisture entering through the hood seals. It is also not uncommon for a problem to arise after improperly cleaning the throttle - if, during assembly, the sensor TPS was installed skewed or its contacts were damaged.

⚠️ Attention: If the error P2135 accompanied by code P0120 or P0220, this almost always indicates a malfunction of the sensor itself TPS. In this case, cleaning the throttle will not help - the sensor needs to be replaced.

How to diagnose error P2135 yourself

For an accurate diagnosis you will need OBD-II scanner (For example, ELM327 or Launch CReader) and a multimeter. If you don’t have a scanner, you can get by with the “old-fashioned” method - checking the voltages manually. Below are step-by-step instructions.

Step 1: Reading Error Codes

Connect the scanner to the connector OBD-II (located under the steering wheel, to the left of the brake pedal). Write down all codes, even if other than P2135 there are others. Particularly important:

• 🔧 P0120/P0122/P0123 - problems with the sensor circuit TPS.
• 🔌 P0220/P0222/P0223 - sensor malfunction APP (gas pedal).
• ⚡ P0507 — high idle speed (may indicate air leaks).

Step 2: Checking the TPS Sensor

Disconnect the connector from the sensor TPS (located on the throttle assembly). Using a multimeter in voltmeter mode, measure the voltage between the contacts:

• 🔋 Contact 1 (ground) - must show 0 V relative to the body.
• 🔌 Pin 2 (+5 V) - supply voltage from the ECU (must be 4.8–5.2 V).
• 📊 Pin 3 (signal) - with the damper closed 0.3–0.7 V, when fully opened 3.8–4.5 V.

If the voltage on pin 3 does not change smoothly or there are surges, the sensor is faulty. Also check the resistance between the signal contact and ground: it should be within 1–10 kOhm (depending on the position of the damper).

Disconnect the sensor connector|Check the supply voltage (pin 2)|Measure the signal on pin 3 with the damper closed/open|Round the circuit for an open or short-->

Step 3: Accelerator Pedal Sensor (APP) Diagnosis

Sensor APP on Almera Classic rarely fails, but its contacts often oxidize. To check:

1. Remove the plastic cover under the gas pedal.
2. Disconnect the sensor connector and inspect the contacts for corrosion.
3. Test the circuit between the sensor connector and the ECU (the connection diagram is in the manual).

If the resistance between the sensor contacts changes nonlinearly when you press the pedal, replacement is required. On Almera Classic sensor APP It often comes complete with a pedal, so repairing it is impractical.

Step 4: Checking the Throttle Body

A dirty or worn throttle body can cause P2135 due to mechanical jamming. To diagnose:

1. Remove the air duct corrugation and inspect the damper for carbon deposits.
2. Check the valve movement manually - it should open/close without jamming.
3. If there is play or the damper is “biting”, the unit needs to be cleaned or replaced.

⚠️ Attention: After cleaning the throttle necessarily follow the procedure "learning" dampers through a scanner or manually (disconnect the battery for 10 minutes, then start the engine and let it idle for 5 minutes). Without this, the ECU will generate an error due to a discrepancy between the actual and expected throttle position.

Cleaning the throttle valve: step-by-step instructions

If diagnostics show that the problem is a dirty throttle, you can clean it yourself. For Nissan Almera Classic Any carburetor cleaner will do (for example, LIQUI MOLY Pro-Line Drosselklappen-Reiniger).

Carburetor cleaner|Lint-free rag|Screwdriver (phillips)|Flat head screwdriver for removing clamps|Gloves-->

Step by step process:

1. Remove the negative terminal from the battery (required!).
2. Loosen the clamps and remove the air duct corrugation from the throttle assembly.
3. Disconnect the sensor connector TPS (do not pull the wires!).
4. Remove the 4 bolts securing the throttle body to the intake manifold.
5. Wash the valve and channels with cleaner, removing carbon deposits with a rag. Do not use metal brushes!
6. Blow with compressed air (for example, a compressor) to remove any remaining dirt.
7. Reassemble everything in reverse order, connect the connectors.

After assembly, run throttle learning:

1. Connect the battery.
2. Turn on the ignition for 5 seconds (without starting the engine).
3. Turn off the ignition for 10 seconds.
4. Start the engine and let it idle for 5 minutes.

If after cleaning there is an error P2135 remains, the problem lies deeper - in the sensors or wiring.

Replacing the Throttle Position Sensor (TPS)

If the diagnostics show a malfunction TPS, it needs to be replaced. On Nissan Almera Classic Sensors with catalog numbers are installed:

• 🔧 Original: 22680-4M200 or 22680-4M205 (depending on the year of manufacture).
• 🔧 Analogues: ERA 550463, Blue Print ADT33303, Valeo 474136.

Replacement instructions:

1. Disconnect the battery.
2. Remove the air duct corrugation.
3. Disconnect the sensor connector TPS.
4. Unscrew the 2 screws securing the sensor (usually a Phillips screwdriver).
5. Remove the old sensor and install the new one, aligning the marks.
6. Tighten the screws firmly 0.5–0.7 Nm (do not overtighten!).
7. Connect the connector and reassemble everything in reverse order.

After replacement necessarily Perform throttle learning (see instructions above). If the new sensor also gives an error, check:

• 🔌 Quality of contacts in the connector (perhaps the “mother” parts are oxidized).
• 📶 Integrity of the wiring from the sensor to the ECU (check with a multimeter).
• 🖥️ The performance of the ECU itself (rarely, but it happens that the unit is “buggy”).

How to check wiring from TPS to ECU

Disconnect the connectors on the sensor and ECU. Test the circuit between pin 2 of the sensor (+5 V power supply) and pin 47 on the ECU connector (check the contact numbers in the diagram). The resistance should be close to 0 ohms. Check the signal wire (sensor track 3 → computer track 48) and ground (sensor track 1 → computer track 45) in the same way.

Problems with the ECU and firmware

In rare cases, an error P2135 on Nissan Almera Classic occurs due to malfunctions electronic control unit (ECU). This may happen after:

• 🔌 Battery shutdown while the engine is running.
• ⚡ “Lighting” from another car with the wrong polarity.
• 🖥️ Unsuccessful ECU flashing.

Symptoms of an ECU glitch:

• 🚨 Error P2135 appears chaotically, without connection with the load on the engine.
• 🔧 Together with P2135 other errors appear (for example, P0606 — ECU internal memory failure).
• ⚡ The engine stalls even after resetting the errors.

What to do:

1. Reset ECU adaptations via scanner (function Reset ECU or Clear Adaptations).
2. If it doesn't help - reflash the ECU original firmware (better in the service).
3. As a last resort, replace the block (with Almera Classic ECU with catalog number is suitable 23710-4M200 or 23710-4M205).

⚠️ Attention: If you suspect a faulty ECU, don't try to reflash it yourself no experience. Incorrect firmware can completely “kill” the unit, and it will have to be replaced with a new one.

Common repair mistakes and how to avoid them

Many owners Nissan Almera Classic are faced with the fact that after repair there is an error P2135 returns. This occurs due to typical errors:

• 🔧 Throttle learning failed after cleaning or replacement TPS. The ECU continues to use the old calibration data.
• 🔌 Connector contacts are damaged during assembly. For example, the “legs” of the sensor are bent TPS.
• 🧹 An aggressive cleaner was usedwhich has damaged the throttle plastic parts or rubber seals.
• 🖥️ Errors not cleared after repair. Old codes may “hang” in the ECU memory and interfere with correct operation.

How to avoid problems:

• 🔹 Always disconnect the battery before working with sensors.
• 🔹 Use only specialized cleaners (for example, for throttle valves).
• 🔹 After renovation reset errors scanner and perform damper training.
• 🔹 Check quality of contacts after assembly, they should fit tightly, without play.

FAQ: Frequently asked questions about error P2135

Is it possible to drive with error code P2135?

Short term - yes, but not recommended. The engine will operate in emergency mode with limited speed (usually up to 2000–3000 rpm), which is dangerous when overtaking or driving uphill. In addition, ignoring the error can lead to increased wear of the throttle and catalyst.

How much does it cost to replace the TPS sensor on Almera Classic?

The cost depends on the type of sensor:

• 🔹 Original (22680-4M200) — 3000–5000 ₽.
• 🔹 Analogue (ERA, Blue Print) — 1500–2500 ₽.
• 🔹 Replacement work in the service - 800–1500 ₽.

When purchasing a sensor, pay attention to compatibility with your year of manufacture. Almera Classic (before 2006 or after).

Can P2135 be caused by bad gasoline?

No, directly P2135 not related to fuel quality. However, bad gasoline can cause throttle valve contamination, which will ultimately lead to mechanical jamming and discrepancies in sensor signals. If the error appears after refueling, also check the codes P0171/P0172 (lean/rich mixture).

How to reset error P2135 without a scanner?

You can reset the error by disconnecting the battery:

1. Remove the negative terminal from the battery.
2. Press the brake pedal and hold for 30 seconds (discharges the ECU capacitors).
3. Reconnect the terminal.
4. Start the engine and let it run for 5-10 minutes.

This method clears all errors, but if the problem persists, P2135 will appear again.

Where is the ECU located on the Nissan Almera Classic?

The electronic control unit is located under the center console, to the right of the gas pedal. To access:

1. Remove the plastic trim under the steering wheel.
2. Unscrew the 2 bolts securing the ECU (using a Phillips screwdriver).
3. Carefully pull out the unit, disconnecting the connectors.

Be careful - the ECU is afraid of moisture and static electricity!