Trouble P0037 - Oxygen Sensor Heater 2 Bank 1 - Circuit Low Voltage

What does error P0037 mean?

Trouble code P0037 is a general trouble code that indicates that the engine control module (ECM) has detected that the oxygen sensor 2 (bank 1) heater circuit voltage is too low. The vehicle's ECM uses an oxygen sensor to monitor the oxygen content of the vehicle's exhaust gases. The ECM uses the signal received from the oxygen sensor to regulate the fuel/air mixture ratio of the engine. The most optimal ratio of air and fuel in the mixture supplied to the engine cylinders is 14.7:1. It is this ratio that is necessary to achieve maximum engine power and optimal fuel consumption. The oxygen sensor heater is used to heat the internal components of the oxygen sensor to provide faster feedback to the vehicle's ECM. This is necessary to reduce emissions of harmful substances from the vehicle's exhaust gases when starting the engine, especially if the engine is started in a cold state.

Deciphering Avensis fault codes

Unlike the first generation T22, in the second release of T25 from 2004-2005, two-digit blink codes appeared that can be read during self-diagnosis and checked with the table above or in the user manual. The self-diagnosis procedure looks like this:

• find the DLC1 connector under the hood of the car;
• take a thin metal jumper (for example, wire);
• using the diagram on the protective cover of the connector box, find contacts TE1 and E1;
• install a jumper to connect the contacts;
• turn on the ignition with the heating/air conditioning turned off;
• Wait for the Check Engine light to flash.

The number of flashes indicates the code. The gap between two ciphers exceeds 2 seconds. Between tens and ones - one and a half. An interval smaller than this indicates units.

Error C1201: Toyota Avensis

Often found in cars produced in 2006-2008. Indicates poor throttle operation. The repair consists of cleaning the damper and intake manifold.

Avensis 2: error C1203

Occurs when the automatic transmission control module breaks down. In most cases it needs to be replaced.

Error C1246

Indicates a malfunction of the pressure sensor in the master cylinder of the brake system. Usually associated with contact problems or breakdown of the ABS system.

B2799 - Avensis malfunction

This error first began to appear on the 1998 modification. It is associated with a broken ignition coil, the replacement of which is important.

Faults 21 and 24

Their appearance indicates problems with the fuel temperature sensor. The device needs to be replaced.

Error 23

In Toyotas 2007 and younger, it indicates problems with the intake air temperature sensor. Most often it needs to be replaced.

Toyota Avensis: error P0037

Occurs when moisture enters the air sensor connector in the lambda probe heater circuit. You can't do without replacement. It happens that the cause of the error is a banal short circuit.

Code P0012

The appearance indicates the need to replace the VVTI coupling.

P0051 - code

Appears when moisture gets into the heated oxygen sensor, causing it to overheat. In many cases, it is enough to get rid of the moisture and the problem will disappear.

Code P0200

This indicates a malfunction in the engine injector wiring, which should be checked for integrity. Sometimes a breakdown of the power unit control unit is to blame.

Malfunction P0500

It speaks of poor contact in the ABS unit.

Code P0556: Avensis

Indicates a problem in the brake booster circuit. Usually, to eliminate it, you need to connect it under the intake manifold.

P1047 - code Avensis

Indicates an open circuit in the VVTI controller. In some cases, the problem lies in the filling of low-quality oil.

Code P1049

Indicates a malfunction in the internal circuit of the Valvematic control unit. In most cases, the latter will need to be replaced.

TRC VSC error

Most often the reason lies in poor contact. If the TRC OFF and VSC lamps light up together, then the sensors on the drive wheels are faulty. In winter, this may indicate a simple failure of the on-board computer due to frost. If the check light is also on, then the problem should be looked for in the engine.

PS Error

Indicates problems with the power supply to the power steering. Contact verification required.

Climate control errors

If a car owner encounters a set of codes 21, 23, 24, 41, 46, then with the maximum probability he has encountered a similar breakdown. Check the contacts and integrity of the wiring, the functionality of system sensors that are prone to failure.

ABS faults: Avensis 2

The appearance of errors 11, 12, 13 and 14 signals similar breakdowns. Contacts deserve special attention. You need to check them carefully before you start checking the block itself.

Causes of error P0037

The P0037 code will appear if the vehicle's ECM detects that the O2 Sensor 2 (Bank 1) heater circuit voltage is too low (compared to the manufacturer's specification). The most common causes for this error include a faulty heated oxygen sensor, damaged electrical wires or connector, a faulty heating element inside the sensor, or a power or grounding problem. In rare cases, the problem may be a faulty engine control module (ECM).

Diagnosis and problem solving

Trouble P0037 can only be caused by the oxygen sensor heater circuit or the oxygen sensor itself. Diagnostics usually begins with checking the sensor wiring. Typically the heated oxygen sensor comes with four wires.

Two wires go directly to the heater circuit, and the other two are for powering and grounding the sensor. You may need a wiring diagram for your car. To be sure you are testing the correct set of wires.

Wiring check

Test the heater circuit using a digital multimeter or volt-ohmmeter. Consult your vehicle's wiring diagram to determine the exact pinout of the ground connector.

The reading should be close to the battery voltage. If this is not the case, then there is most likely a problem with the sensor's power supply.

It is also necessary to check the grounding. To do this, you need to connect the positive terminal of the battery to the red wire of the multimeter. And the black wire to ground to check the grounding of the circuit. The result should be 12V, if not then this indicates a grounding problem at the sensor.

Sensor check

If the power and ground are ok, then the next option is to check the sensor heating element. To determine if it has an open circuit or high resistance.

Set the volt-ohm meter to Ohm scale, check the resistance of the heater circuit using the electrical diagram as a reference.

Make sure you have disconnected the O₂ sensor. The heater circuit inside the sensor should have little resistance. Exceeding the limit value indicates a break in the heating part. Therefore, the oxygen sensor will have to be replaced.

What are the symptoms of a P0037 code?

When this error occurs, the Check Engine light on the vehicle's dashboard will light up, indicating a malfunction. If the vehicle's ECM detects low voltage in the oxygen sensor heater circuit, it will put the engine into limp mode. Staying in limp mode can cause a number of vehicle handling problems, which can vary depending on the make and model of the vehicle. The vehicle will remain in limp mode until the error is resolved. There may be a drop in power, rough idling, and unstable engine operation.

Why does error P0037 appear?

This system malfunction can occur due to a number of problems. Among them the following are considered popular:

• Absence or interruption of the sensor heating circuit or power cable.
• The sensor heater is not working.
• The connection is damaged or completely faulty.
• The Power Control Module is not working.

Often, the problems that create error P0037 arise due to poor wire connections, low battery charge, or rusty connectors.

How does a mechanic diagnose a P0037 code?

First, the mechanic reads all the stored data and error codes using an OBD-II scanner. He will then clear the error codes from the computer's memory and test drive the vehicle to see if the P0037 code appears again. If the error code appears again, the mechanic will visually inspect the heated oxygen sensor for damage, as well as check the ground and measure the voltage at the sensor. The mechanic will then carefully check any associated electrical wires that may have been damaged due to excessive heat due to high exhaust temperatures.

The cost of diagnosing errors for Ford at service stations in Moscow and St. Petersburg

Approximate prices for computer diagnostics of faults:

How serious is P0037?

When a P0037 error occurs, the Check Engine light on your vehicle's dashboard will illuminate, indicating a problem. Failure of the heated oxygen sensor may cause the vehicle's ECM to not be able to properly regulate the fuel/air mixture in the engine. The vehicle's engine may run erratically. It may also increase fuel consumption and damage other vehicle components. If this code is detected, it is recommended that you contact a qualified technician as soon as possible to diagnose and resolve the error.

Often, if the Check Engine Light comes on immediately after starting the engine, the OBD-II system can be reset and the vehicle will continue to operate normally.

Error table

The main codes unique to the model can be found in the table below:

What repairs can fix the P0037 code?

To resolve error P0037 you may need to:

• Clearing error codes from the ECM and test driving the vehicle to see if the P0037 code appears again
• Heated Oxygen Sensor 2 (Bank 1) Replacement
• Repair or replace electrical wires or connector for heated oxygen sensor 2 (bank 1)
• Replacing the fuse in the oxygen sensor 2 heater circuit (bank 1)
• Cleaning or replacing the heating element inside the oxygen sensor
• In rare cases, replacing the engine control module (ECM)

Fuses and relays Toyota Avensis T27

Toyota Avensis cars of 2009, 2010, 2011, 2012, 2013, 2014, 2015 were considered.

Fuse and relay box in the engine compartment.

Fuse layout diagram in the mounting block.

Electric cooling fans

Electric cooling fans

Anti-lock braking system. VSO

Air conditioning system

Charging system, RDI FAN, CDS FAN. H-LP CLN, PWR SEAT LH. FUEL OPN, ABS N0.1, ABS N0.2. FR DEICER. P.S.B. HTR. STV HTR, PWR OUTLET. HTR SUB N0.1, HTR SUB N0.2. HTR SUB N0.3, ECU-IG N0.2. HTR-IG. WIPER. RR WIPER. WASHER. ECU-IG N0.1. ECU-IG N0.3, SEAT HTR. AM1, DOOR. STOP. P FR DOOR, POWER. RR DOOR. R.L. DOOR. OBD. ACC-B, RR FOG. FR FOG. Tl&TE. SHADE. PWR SEAT RH. DEF, TAIL. PANEL

Electric power steering

Engine heating system

EFI MAIN. HORN. IG2. EDU

H-LP LH LO. H-LP RH LO. H-LP LH HI. H-LP RH HI

Electric parking brake

Door lock system

Intelligent entry and start system, air conditioning system, identification search module. electric windows, electric seat adjustment

Instruments and gauges, ECU main body. Steering sensor, warning light, dual locking system, remote control, intelligent entry and start system, steering wheel tilt and reach adjustment

Trunk/Cargo Compartment Lights, Personal Mirror Lights, Engine Switch Lights, Front Door Lights, Personal/Interior Lights, Personal Lights, Footwell Lights

Turn signals, hazard warning lights

Electronic throttle control system

Exhaust system

Steering lock system

Multiport fuel injection system/sequential multiport fuel injection system, ignition system

Multiport fuel injection system/sequential multiport fuel injection system

Distributed fuel injection system

distributed fuel injection system, automatic transmission. EFI NO 1. EFI NO 2. EFI N03

Air conditioning system

Air conditioning system

Air conditioning system

Power seats, lumbar support

Seat belt with pre-collision system

Fuel tank filler door release button

Heated windshield wiper blade area

Anti-lock braking system. V.S.C.

Air intake system, air flow meter, exhaust gas exhaust system

Multiport fuel injection system/sequential

distributed fuel injection system, air flow meter, exhaust system

Right headlight (high beam)

Left headlight (high beam)

Right headlight (low beam)

Additional comments for troubleshooting P0037

Many high mileage vehicles (usually over 150,000 kilometers) have short-term problems with sensors, which usually occur when the engine is started or the transmission is subjected to prolonged stress. Often, if the Check Engine Light comes on but the vehicle continues to operate normally, the OBD-II system can be reset and the problem will be resolved. This is why it is important to check for an error code using a scanner and clear the code from the computer's memory before performing any repair work.

On which cars is this problem most common?

The problem with code P0037 can occur on different machines, but there are always statistics on which brands this error occurs more often. Here is a list of some of them:

• Acura
• Audi
• Chery
• Chevrolet (Chevrolet Aveo, Cruz)
• Chrysler (Chrysler PT Cruiser)
• Citroen (Citroen C4)
• Daewoo (Daewoo Nexia)
• Dodge
• Ford (Ford Fiesta, Focus, Fusion)
• Honda
• Hyundai (Hyundai Santa Fe)
• Infiniti (Infiniti fx35, g35)
• Jaguar
• Jeep (Jeep Wrangler, Grand Cherokee)
• Kia
• Lexus (Lexus gs300, rx300, rx330)
• Lifan (Lifan x60)
• Mazda (Mazda 3, Mazda 6, Mazda cx7, Protege, MPV)
• Mitsubishi (Mitsubishi ACX, Outlander, Lancer, Pajero)
• Nissan (Nissan Almera, Altima, Murano, Teana)
• Peugeot (Peugeot 207, 308)
• Skoda (Skoda Octavia, Fabia)
• Subaru (Subaru Impreza, Legacy, Forester)
• Suzuki (Suzuki Vitara, Grand Vitara, Liana, Forenza)
• Toyota (Toyota Avensis, Camry, Corolla, Rav4, Sienna)
• Volkswagen (Volkswagen Golf, Jetta, Polo Sedan)
• Volvo (Volvo s40, s60, s80, v70)
• VAZ 2107, 2114
• Lada Niva
• UAZ Bukhanka, Patriot

With fault code P0037, you can sometimes encounter other errors. The most common are: P0016, P0030, P0031, P0036, P0050, P0051, P0057, P0138, P0140, P0218, P0261, P0264, P0267, P0270, P0404, P0418, P0444, P0445, P0714, P113 8, P1684.