Error P0037 on Nissan: what does it mean, how to fix the low signal of the second oxygen sensor

Fault code P0037 on cars Nissan - one of the most common problems associated with the exhaust system. This code points to low signal level in the second oxygen sensor (bank 1), which can lead to increased fuel consumption, loss of power and even damage to the catalyst. Model owners Qashqai, X-Trail, Juke, Almera and others often encounter this error, but do not always understand its true causes.

Unlike other errors on oxygen sensors (for example, P0130 or P0150), P0037 specifically signals problems with heating element second lambda probe. This means that the sensor either does not warm up to operating temperature, or its signal is too weak for the ECU to operate correctly. In this article we will analyze unique diagnostic features of P0037 on Nissan engines HR16DE, MR20DD And QR25DE, and also give step-by-step recommendations for repairs - from checking the wiring to replacing the sensor.

What does P0037 mean on Nissan?

Code P0037 stands for «Heated Oxygen Sensor (HO2S) Heater Control Circuit Low (Bank 1, Sensor 2)». This means that the engine control unit (ECU) discovered low voltage in the second oxygen sensor heater circuit (located after the catalyst).

Second oxygen sensor (also called lower or diagnostic) serves to monitor the efficiency of the catalyst. Its heating element must quickly warm the sensor to operating temperature (~600°C) to ensure accurate readings. If the heater is faulty, the sensor produces a weakened signal, which is recorded as an error P0037.

• 🔧 The main function of the second sensor: monitoring of oxygen content in exhaust gases after the catalyst.
• ⚡ Reason for error: low voltage in the heater circuit (open circuit, short circuit, faulty sensor).
• ⚠️ Consequences of ignoring: increased fuel consumption, risk of catalyst overheating, possible failure of the OBD-II system.

On Nissan with engines HR16DE (For example, Juke, Note) and MR20DD (Qashqai J11, X-Trail T32) error P0037 often accompanied P0057 (similar problem, but for bank 2). This is due to the design features of the exhaust system, where the sensors of both banks are connected to the same wiring harness.

Causes of error P0037

Error P0037 can be caused by both mechanical malfunctions of the sensor and problems in the electrical circuit. Below is a complete list of possible causes, ranked by frequency of occurrence on Nissan:

Reason	Frequency of occurrence	Diagnostic method
Faulty oxygen sensor heating element	60%	Checking the heater resistance with a multimeter
Open or short circuit in wiring	25%	Visual inspection + chain continuity
Oxidation of contacts in the sensor connector	10%	Cleaning contacts, checking connection reliability
Malfunction of the control unit (ECU)	3%	Diagnostics with a scanner, checking the voltage at the ECU output
Engine weight problems	2%	Checking the integrity of mass wires

By car Nissan Almera N16 And Primera P12 with engines QR25DE common broken wiring in the harness going to the oxygen sensors. This is due to the close location of the harness to the exhaust manifold, where the wires rub against metal elements. Also, on models with a mileage of more than 150,000 km, the sensor itself often fails - its heating element degrades over time.

⚠️ Attention: If the error P0037 appears along with P0138 or P0158, this almost always indicates open circuit heater. In this case, replacing the sensor without checking the wiring may cause the error to reoccur.

Symptoms of error code P0037 on Nissan

Error P0037 does not always manifest itself with obvious signs, but there are several characteristic symptoms that are worth paying attention to:

• 🚨 Check Engine Light: The main symptom is that the engine malfunction indicator lights up. On some models (for example, Nissan Qashqai J10) may flash.
• ⛽ Increased fuel consumption: Due to incorrect sensor readings, the ECU goes into emergency mode, enriching the mixture.
• 🐢 Loss of dynamics: The car accelerates worse, especially at low speeds.
• 🔥 Unstable idle: The speed may fluctuate or the engine may stall when stopped.

On Nissan X-Trail T31 And Murano Z51 with engines VQ25DE error P0037 sometimes accompanied popping sounds in the exhaust system. This is due to the fact that a faulty sensor provokes incorrect operation of the injection system, due to which the fuel burns out already in the outlet.

It is important to note that on some vehicles (eg. Nissan Juke F15) error may appear periodically - for example, only during a cold start or after a long trip. This often indicates problems with wiring that is oxidizing or overheating.

Diagnosing error P0037: step-by-step instructions

To pinpoint the cause of the error P0037, it is necessary to conduct a comprehensive diagnosis. Below are step-by-step instructions adapted for Nissan taking into account the features of their electrical circuits.

1. Read error codes with a scanner (for example, ELM327)

2. Visually inspect the sensor and wiring for damage

3. Check the resistance of the sensor heater

4. Ring the heater power circuit (from the ECU to the sensor)

5. Check the voltage at the sensor connector with the ignition on -->

Step 1: Reading Error Codes

Use a diagnostic scanner (eg Launch CReader or ELM327) to read all stored errors. Please note:

• If together with P0037 There is P0136 or P0156, the problem is most likely in the sensor itself.
• If there are errors in the power supply (for example, P0030), check the wiring and fuses.

Step 2: Visual Inspection

Inspect the second oxygen sensor (located after the catalyst) and its wiring:

• 🔍 Check the integrity of the wires - they should not be melted or frayed.
• 🔌 Make sure that the sensor connector is not oxidized and sits tightly.
• 🚗 On Nissan Qashqai J11 Pay attention to the harness near the thermal shield - the wires often fray there.

Step 3: Check Heater Resistance

To do this:

1. Disconnect the sensor connector.
2. Connect a multimeter in ohmmeter mode to the heater contacts (usually these are contacts 3 And 4 on the sensor connector).
3. Normal resistance: 2–10 ohms (depending on the sensor model). If the resistance tends to infinity, there is a break; if it is close to 0, there is a short circuit.

Step 4: Checking the Supply Voltage

Connect a multimeter in voltmeter mode to the heater power contacts (usually +12V And mass) with the ignition on. The voltage should be not less than 10.5 V. If there is no voltage, the problem is in the wiring or ECU.

⚠️ Attention: On Nissan Note E12 And Micra K13 with engines HR16DE Power to the sensor heaters comes through a relay located in the fuse box under the hood. If there is no voltage, check this relay (usually it is labeled as O2 Sensor Heater).

How to fix error P0037: repair methods

Depending on the cause identified during diagnosis, there are several ways to eliminate the error. P0037. Let's look at them in detail.

1. Replacing the oxygen sensor

If the diagnostics showed a malfunction of the sensor itself (break or short circuit of the heater), it must be replaced. For Nissan The following original and similar sensors are suitable:

Model Nissan	Original article	Analogs (brand)
Qashqai J10/J11, X-Trail T31/T32	22690-4M000 or 22690-4M005	Bosch (0 258 006 537), Denso (DOX-0209)
Juke F15, Note E12	22690-4M010	NGK (NTK 25177), Walker (250-24204)
Almera N16, Primera P12	22690-AL500	Bosch (0 258 005 133), Denso (DOX-0109)

When replacing the sensor:

• 🔧 Use a special key for lambda probes (on 22 mm).
• 🧴 Apply graphite lubricant to the threads of the new sensor to avoid sticking.
• ⚠️ Do not use excessive force when tightening - the tightening torque is usually 40–50 Nm.

2. Wiring repair

If the problem is in the wiring, proceed as follows:

1. Find the area where the wire is broken or chafed (often this is the area near the exhaust manifold).
2. Strip and solder the damaged wire, insulating the repair area with heat shrink tubing.
3. Check the integrity of the ground wire (on Nissan it is usually black and goes to the cylinder block).

On Nissan Pathfinder R51 And Navara D40 A common problem is the oxidation of contacts in the sensor connector. In this case, it is enough to clean the contacts with a special liquid (for example, Contact Cleaner) and apply dielectric grease.

3. Checking fuses and relays

On some models (for example, Nissan Teana J32) The sensor heaters are powered through separate fuses and relays. Their location:

• 🔋 Fuse: usually 15A in the block under the hood (position may vary).
• 🔄 Relay: often labeled as O2 Heater or Lambda.

⚠️ Attention: On Nissan Murano Z50 with engine VQ35DE The oxygen sensor heater relay is combined with the fuel pump relay. If after replacing the relay there is an error P0037 remains, check for an open circuit between the relay and the ECU.

Common repair mistakes and how to avoid them

Many owners Nissan make typical mistakes when troubleshooting P0037, which causes the problem to reappear. Let's look at the most common of them.

• 🛠️ Replacing the sensor without checking the wiring: if the cause is a broken wire, the new sensor will quickly fail.
• 🔌 Using non-original low quality sensors: Cheap analogues often have incorrect heater resistance.
• 🔥 Ignoring power supply errors: If the ECU is not supplying voltage to the heater, replacing the sensor will not help.
• 📉 Failure to comply with the tightening torque: An overtightened sensor can damage the threads in the manifold.

On Nissan X-Trail T30 And Qashqai J10 with engines MR20DE a situation often occurs when, after replacing the sensor, an error occurs P0037 disappears, but returns after a while. This is due to the fact that the new sensor does not have time to warm up to operating temperature due to faulty thermal screen, which removes too much heat. In this case, it is recommended to install additional thermal insulation on the exhaust pipe in front of the sensor.

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

If a new sensor is installed, but an error P0037 has not disappeared, follow these steps:

1. Check the voltage at the sensor connector with the ignition on (should be ~12V).

2. Make sure that the sensor ground is securely connected to the body (check the resistance between the sensor ground contact and the negative terminal of the battery - it should be close to 0).

3. Check the circuit from the ECU to the sensor for a break.

4. If everything is in order, but the error remains, there may be a malfunction of the ECU itself (diagnostics required at a service station).

Preventing error P0037 on Nissan

To minimize the risk of errors P0037, follow these guidelines:

• 🛢️ Use quality fuel: Bad gasoline accelerates the wear of oxygen sensors.
• 🔧 Check the condition of the wiring regularly: especially on cars with more than 100,000 km.
• 🚗 Avoid driving through deep puddles: water entering the sensor connectors leads to corrosion of the contacts.
• 🔥 Don't ignore the Check Engine error: Driving for a long time with a faulty sensor can damage the catalyst.

On Nissan Qashqai J11 And X-Trail T32 with engines MR20DD It is recommended to clean the contacts of oxygen sensors from oxidation every 50,000 km. To do this, simply remove the connector, treat the contacts with a cleaner (for example, WD-40 Contact Cleaner) and apply dielectric grease.

Also note exhaust system condition. A burnt or deformed thermal shield can lead to overheating of the sensor, which shortens its service life. On Nissan Juke And Note this is especially true due to the compact engine compartment.

FAQ: Frequently asked questions about error code P0037 on Nissan

Is it possible to drive with error code P0037?

Short term - yes, but not recommended for long term. Driving for a long time with a faulty second oxygen sensor can lead to:

• Increased fuel consumption by 10–15%.
• Overheating and failure of the catalyst (replacement cost - from 30,000 rubles).
• Problems with passing technical inspection (diagnostic devices detect an OBD-II malfunction).

On Nissan Almera G15 And Sentra B17 ignoring P0037 may also lead to errors in the fuel mixture (P0171, P0174).

How much does it cost to replace an oxygen sensor on a Nissan?

The cost depends on the model and type of sensor:

• Original sensor: 5,000–12,000 rubles.
• Analogue (Bosch, Denso, NGK): 2,500–6,000 rubles.
• Replacement work: 1,000–3,000 rubles (depending on the complexity of access).

On Nissan Patrol Y62 And Navara D23 Replacing the sensor may cost more due to the need to remove protection or exhaust system components.

Is it possible to reset the P0037 code without repair?

Technically, yes - you can reset the error with a scanner or by disconnecting the battery for 10-15 minutes. However:

• The error will return if the cause is not eliminated.
• On some models (for example, Nissan Teana L33) after reset may be required throttle adaptation.
• Resetting does not eliminate the consequences of the malfunction (increased consumption, risk of damage to the catalyst).

Which oxygen sensor should I choose for replacement?

Recommendations for selection:

• For Nissan Qashqai J11 And X-Trail T32 optimal choice - Denso DOX-0209 or Bosch 0 258 006 537.
• On Nissan Almera N16 And Primera P12 fits NGK NTK 25177.
• Avoid unbranded sensors - they often have inappropriate heater resistance.

When purchasing, pay attention to number of wires (on Nissan usually 4: two for signal, two for heater).

Why does P0037 only appear when the engine is cold?

This is a typical sign:

• Sensor heater malfunctions: While the engine is cold, the sensor is not warmed up and its signal is weak.
• Weight problems: When the engine warms up, contact may be temporarily restored.
• Contact oxidation: The moisture in the connector evaporates when it warms up, and the error disappears.

On Nissan Juke F15 And Note E12 this is often associated with condensation in the connector, which evaporates after the engine starts.