P2031 Exhaust Gas Temperature (EGT) Sensor Circuit Malfunction (Bank 1 Sensor 2)

P2031 Exhaust Gas Temperature (EGT) Sensor Circuit Malfunction (Bank 1 Sensor 2) is a generic OBD-II diagnostic trouble code indicating that the vehicle's control module has detected a malfunction in the exhaust gas temperature (EGT) sensor circuit associated with Bank 1 Sensor 2.

The EGT sensor monitors exhaust gas temperature and sends an electrical signal to the engine control module (ECM), powertrain control module (PCM), or an aftertreatment control module.

In simple terms, the vehicle's computer has detected that the Bank 1 Sensor 2 EGT sensor or its electrical circuit is not operating as expected.

Unlike a specific Circuit Low or Circuit High code, P2031 does not identify only one electrical condition. The problem may involve the sensor itself, its wiring, connector, power or ground circuit, signal circuit, or the control module.

Possible causes include:

• Faulty EGT sensor

• Damaged wiring

• Open circuit

• Short circuit

• Short to ground

• Short to voltage

• Corroded connector

• Loose terminals

• Poor electrical connection

• Incorrect sensor resistance

• Sensor contamination

• Heat damage

• Incorrect sensor installation

• Reference or supply-voltage problems

• Control-module problems

Proper diagnosis is necessary to identify the actual cause.

---

What Does P2031 Mean?

The code description contains several important terms.

Exhaust Gas Temperature (EGT) Sensor

An EGT sensor measures the temperature of exhaust gases.

The control module uses this information to monitor and control various exhaust and emissions-related systems, including:

• Catalytic converters

• Diesel particulate filters (DPF)

• Selective Catalytic Reduction (SCR) systems

• Turbochargers

• Exhaust components

• Emissions-control systems

Depending on the vehicle, EGT information can be used for:

• DPF regeneration

• Catalyst temperature monitoring

• Exhaust thermal protection

• SCR operation

• Emissions diagnostics

• Turbocharger protection

---

Circuit Malfunction

The term "Circuit Malfunction" indicates that the control module has detected an abnormality in the EGT sensor circuit.

Unlike:

Circuit Low

or

Circuit High

P2031 does not specifically identify whether the signal is too low or too high.

The control module may detect a malfunction because:

• The signal is missing

• The signal is implausible

• The sensor resistance is incorrect

• The circuit is open

• The circuit is shorted

• The signal changes incorrectly

• The sensor does not respond to temperature changes

• The electrical characteristics are outside the expected operating range

The exact diagnostic strategy varies by manufacturer.

---

Bank 1

Bank 1 refers to the side of the engine containing cylinder number one.

On V-type engines:

• Bank 1 = side containing cylinder number one

• Bank 2 = opposite side

P2031 specifically identifies Bank 1.

Inline engines normally have only one cylinder bank.

---

Sensor 2

Sensor 2 identifies the EGT sensor position within the vehicle's exhaust-temperature monitoring system.

It is important not to assume that Sensor 2 always means the sensor immediately after the catalytic converter.

The exact location can vary according to:

• Engine design

• Exhaust layout

• DPF arrangement

• SCR system

• Turbocharger configuration

• Manufacturer

• Model

• Engine version

On some vehicles, Bank 1 Sensor 2 may be positioned around or downstream of a catalyst or particulate filter.

The exact location should be confirmed using the vehicle-specific service information and wiring diagram.

---

How Does an EGT Sensor Work?

EGT sensors can use different technologies.

Many applications use thermistor-type sensors, while others use thermocouple-based designs.

With a thermistor-type sensor, the electrical resistance changes as exhaust temperature changes.

A simplified process is:

Exhaust temperature changes → Sensor electrical characteristics change → Control module reads the signal → ECM calculates exhaust temperature

The control module continuously evaluates whether the EGT signal is plausible.

If the signal is missing, unstable, implausible, or outside the expected electrical characteristics, P2031 may be stored.

The exact voltage, resistance, temperature relationship, and diagnostic thresholds are vehicle-specific.

---

Why Is EGT Temperature Important?

Accurate EGT information is important for modern engine and emissions systems.

The control module needs reliable temperature information to:

• Protect exhaust components from excessive heat

• Control DPF regeneration

• Monitor catalyst temperature

• Monitor SCR operation

• Maintain emissions performance

• Protect turbocharger components

On diesel vehicles, EGT sensors can be especially important during DPF regeneration.

If the control module cannot reliably determine exhaust temperature, it may modify, interrupt, or prevent certain emissions-control strategies.

---

Symptoms of P2031

Symptoms depend on the vehicle and the underlying circuit problem.

Check Engine Light

The Check Engine Light is the most common symptom.

---

Exhaust or Emissions Warning

Some vehicles may display:

• Exhaust system fault

• Emissions system fault

• Engine system fault

• DPF warning

• SCR warning

The exact warning message depends on the manufacturer.

---

DPF Regeneration Problems

On diesel vehicles, an EGT sensor circuit malfunction can interfere with DPF regeneration.

Possible symptoms include:

• Regeneration not starting

• Regeneration being interrupted

• Repeated regeneration attempts

• Increasing soot accumulation

• DPF warning

• Regeneration required message

---

Reduced Engine Power

Some vehicles may enter a reduced-power or protective operating mode if the emissions system cannot operate correctly.

---

Increased Fuel Consumption

Repeated or unsuccessful regeneration attempts can increase fuel consumption.

---

Increased Emissions

Incorrect or unavailable EGT information can interfere with emissions-control strategies.

---

Poor Engine Performance

Depending on the vehicle, possible symptoms include:

• Hesitation

• Reduced acceleration

• Uneven engine operation

• Reduced turbocharger performance

---

No Noticeable Symptoms

P2031 can also occur without obvious drivability problems.

The vehicle may continue to operate normally while the Check Engine Light remains illuminated.

---

Common Causes of P2031

Faulty EGT Sensor

A defective EGT sensor is one of the most common possibilities.

The sensor may have:

• Internal electrical failure

• Incorrect resistance

• Intermittent operation

• Slow temperature response

• Incorrect temperature output

---

Damaged EGT Wiring

EGT wiring operates in a high-temperature environment.

Possible damage includes:

• Melted insulation

• Burned wires

• Heat-hardened conductors

• Broken conductors

• Chafing

• Corrosion

---

Open Circuit

A broken wire or disconnected connector can interrupt the EGT sensor circuit.

Possible causes include:

• Broken conductor

• Loose connector

• Failed terminal

• Damaged splice

• Harness damage

---

Short Circuit

A short between circuit wires can alter the electrical characteristics of the EGT sensor circuit.

Possible causes include:

• Melted insulation

• Chafed wiring

• Harness damage

• Incorrect previous repairs

---

Short to Ground

If the signal circuit contacts ground, the sensor signal may be pulled outside its normal operating range.

This can produce an EGT circuit malfunction.

---

Short to Voltage

If the signal circuit contacts battery or ignition voltage, the control module may detect an abnormal sensor signal.

---

Corroded Connector

Moisture, road salt, dirt, and exhaust heat can damage EGT connectors.

Possible problems include:

• Corroded terminals

• Loose pins

• Bent pins

• Damaged seals

• Poor terminal tension

• Intermittent electrical contact

---

Poor Ground or Electrical Connection

A poor electrical connection can cause unstable or implausible EGT readings.

---

Incorrect Sensor Resistance

If the vehicle uses a resistance-based EGT sensor, its resistance must correspond to the actual temperature according to manufacturer specifications.

An incorrect resistance value can cause the control module to interpret the signal as implausible.

---

Sensor Contamination

The sensing element may become contaminated by:

• Soot

• Oil

• Coolant

• Fuel deposits

Contamination can affect the sensor's response and accuracy.

---

Incorrect Sensor Installation

Installing the wrong EGT sensor can cause an electrical or temperature-response mismatch.

This can happen even when the replacement sensor physically fits the exhaust system.

---

Reference or Supply Voltage Problem

Depending on the circuit design, a problem with the sensor's reference or supply voltage can affect the signal.

---

Exhaust Heat Damage

EGT sensor wiring can be exposed to extreme exhaust temperatures.

If the wiring is routed too close to the exhaust, insulation may melt and the conductors may become damaged.

---

Genuine Exhaust Temperature Problem

A circuit malfunction code does not necessarily mean that the exhaust temperature itself is abnormal.

However, if the sensor and circuit test correctly, the technician should also investigate whether the exhaust system is operating outside expected temperature conditions.

Possible causes include:

• Fuel-injection problems

• Misfires

• DPF regeneration problems

• Exhaust restriction

• Turbocharger problems

• Aftertreatment faults

---

DPF Regeneration Problems

On diesel vehicles, an EGT sensor fault can interfere with DPF regeneration.

Possible causes include:

• Excessive soot loading

• Failed regeneration

• Incorrect regeneration control

• Fuel injector problems

• Incorrect EGT feedback

---

Exhaust Restriction

A restricted DPF, catalyst, or exhaust component can alter exhaust temperature and backpressure.

Possible causes include:

• Clogged DPF

• Restricted catalyst

• Collapsed exhaust component

• Excessive soot accumulation

---

Exhaust Leaks

An exhaust leak can change exhaust flow and temperature around the EGT sensor.

The effect depends on:

• Leak location

• Leak size

• Exhaust pressure

• Sensor position

• Engine operating conditions

---

Aftermarket Exhaust Modifications

Exhaust modifications can alter:

• Exhaust flow

• Temperature distribution

• Sensor position

• Sensor exposure

• Wiring routing

These changes may contribute to EGT sensor problems.

---

Control Module Problem

In rare cases, the ECM, PCM, or aftertreatment control module may have an internal problem.

The control module should generally be considered only after the EGT sensor and its external circuit have been thoroughly tested.

---

Vehicles Commonly Affected by P2031

P2031 can occur on vehicles equipped with multiple EGT sensors.

Examples may include:

• Ford F-250 Super Duty Diesel

• Ford F-350 Super Duty Diesel

• Ford Transit Diesel

• Chevrolet Silverado Duramax

• GMC Sierra Duramax

• Ram 2500 Diesel

• Ram 3500 Diesel

• Mercedes-Benz Sprinter Diesel

• Volkswagen Touareg TDI

• Audi Q7 TDI

• BMW X5 Diesel

• BMW X6 Diesel

• Porsche Cayenne Diesel

• Jeep Grand Cherokee Diesel

• Volkswagen Transporter

• Peugeot Boxer Diesel

• Citroën Jumper Diesel

• Fiat Ducato Diesel

• Iveco Daily

• Renault Master

This list is not exhaustive.

The exact EGT sensor arrangement varies between manufacturers, engines, model years, and emissions systems.

---

How Is P2031 Diagnosed?

The key diagnostic question is:

Is the Bank 1 Sensor 2 EGT sensor defective, or is the problem somewhere in its electrical circuit?

Because P2031 is a general circuit-malfunction code, diagnosis should cover the sensor, wiring, connector, power, ground, signal circuit, and control module.

---

Step 1: Scan for Additional Trouble Codes

Use a suitable diagnostic scan tool to retrieve all stored and pending codes.

Look for related faults involving:

• Other EGT sensors

• DPF

• SCR

• NOx sensors

• Fuel injectors

• Fuel pressure

• Turbocharger

• Exhaust restriction

• Regeneration

• Aftertreatment communication

Additional codes can help identify the root cause.

---

Step 2: Review Freeze-Frame Data

Review the conditions under which P2031 was stored.

Check:

• Engine RPM

• Vehicle speed

• Engine coolant temperature

• Intake-air temperature

• Engine load

• EGT readings

• DPF soot load

• Regeneration status

• Battery voltage

This can help determine whether the fault occurred during cold operation, normal driving, or regeneration.

---

Step 3: Check Live EGT Data

Monitor the Bank 1 Sensor 2 EGT reading with a scan tool.

Compare it with:

• Other EGT sensors

• Ambient temperature

• Engine coolant temperature

• Engine load

• Manufacturer specifications

An implausible reading may indicate a sensor or circuit problem.

---

Step 4: Check the Sensor With a Cold Engine

A cold-engine check is particularly useful.

Before the exhaust has become hot, the EGT reading should be plausible relative to ambient temperature and other temperature sensors.

If Bank 1 Sensor 2 immediately displays an extreme or implausible value, investigate the sensor and circuit.

---

Step 5: Inspect the EGT Sensor

Check for:

• Physical damage

• Soot buildup

• Oil contamination

• Coolant contamination

• Corrosion

• Damaged sensor tip

• Incorrect installation

---

Step 6: Inspect the Wiring Harness

Follow the Bank 1 Sensor 2 EGT wiring toward the control module.

Look for:

• Melted insulation

• Burned wires

• Chafing

• Broken conductors

• Exposed wiring

• Previous repairs

• Loose harness clips

Pay particular attention to sections routed near the exhaust.

---

Step 7: Inspect the Connector

Check for:

• Corrosion

• Moisture

• Loose terminals

• Bent pins

• Damaged seals

• Heat damage

• Poor terminal tension

---

Step 8: Check Power and Ground

Using the vehicle-specific wiring diagram and manufacturer diagnostic procedure, verify the applicable:

• Supply voltage

• Reference voltage

• Ground circuit

• Sensor circuit connections

The exact circuit arrangement differs between vehicles.

---

Step 9: Check Sensor Circuit Continuity

Test the wiring between the EGT sensor and the control module.

Look for:

• Open circuits

• Excessive resistance

• Damaged conductors

• Poor connections

Use the manufacturer's specified resistance and continuity limits.

---

Step 10: Check for Shorts

Test the EGT sensor circuit for unwanted connections to:

• Ground

• Battery voltage

• Ignition voltage

• Other circuits

A short can alter the signal and trigger P2031.

---

Step 11: Check Sensor Resistance

If the vehicle uses a resistance-based EGT sensor, measure its resistance according to manufacturer specifications.

Compare the result with the expected resistance for the measured sensor temperature.

---

Step 12: Perform a Wiggle Test

Monitor the EGT sensor signal while carefully moving the harness and connector.

If the signal changes unexpectedly, investigate the wiring and terminals.

This can help identify intermittent connections that are difficult to find during a visual inspection.

---

Step 13: Compare Bank 1 Sensor 2 With Other EGT Sensors

Compare the sensor's reading with other EGT sensors under similar operating conditions.

A large unexplained difference may indicate:

• Sensor failure

• Wiring problem

• Connector problem

• Genuine exhaust-temperature difference

Sensor position must be taken into account because different exhaust locations can naturally have different temperatures.

---

Step 14: Check the Sensor Response to Temperature

The EGT sensor should respond appropriately as exhaust temperature changes.

A sensor that remains fixed, changes erratically, or responds too slowly may be defective.

Follow the manufacturer's specified testing procedure rather than relying on a generic resistance-temperature chart.

---

Step 15: Check for Genuine Exhaust Temperature Problems

If the sensor and electrical circuit test correctly, investigate actual exhaust temperature.

Check:

• Fuel injection

• Combustion

• Misfires

• Turbocharger operation

• DPF regeneration

• Exhaust restriction

• Aftertreatment operation

---

Step 16: Check DPF Regeneration

On diesel vehicles, determine whether P2031 occurs during:

• Active regeneration

• Failed regeneration

• Interrupted regeneration

• Repeated regeneration attempts

An EGT sensor malfunction can prevent the control module from correctly monitoring regeneration temperatures.

---

Step 17: Inspect the DPF and Exhaust System

Check for:

• Excessive soot accumulation

• DPF restriction

• Catalyst restriction

• Exhaust leaks

• Damaged exhaust components

• Abnormal exhaust backpressure

---

Step 18: Check Fuel Injection

Fuel-system problems can affect exhaust temperature and emissions operation.

Inspect:

• Fuel injectors

• Fuel pressure

• Injection timing

• Fuel trims where applicable

• Misfire data

---

Step 19: Check Turbocharger Operation

Turbocharger problems can affect exhaust temperature and flow.

Check:

• Boost pressure

• Turbocharger control

• Wastegate operation

• Variable-geometry operation

• Charge-air leaks

---

Step 20: Check Manufacturer Technical Information

Look for:

• Technical Service Bulletins

• Known EGT sensor failures

• Wiring harness issues

• Connector updates

• Sensor revisions

• Software updates

• DPF regeneration procedures

---

Step 21: Check the Control Module

If the EGT sensor and external wiring have been verified, investigate the ECM, PCM, or aftertreatment control module.

Control-module replacement should only be considered after the external circuit has been thoroughly tested.

---

How to Fix P2031

The correct repair depends on the actual cause of the EGT sensor circuit malfunction.

Replace the Faulty EGT Sensor

If testing confirms that Bank 1 Sensor 2 is defective, replace it with the correct vehicle-specific sensor.

Do not assume that all EGT sensors are interchangeable.

---

Repair Damaged Wiring

Repair or replace wiring damaged by:

• Exhaust heat

• Chafing

• Vibration

• Corrosion

• Road debris

• Previous improper repairs

Route and secure the harness correctly after the repair.

---

Repair an Open Circuit

If the circuit is open, repair:

• Broken wires

• Failed splices

• Loose terminals

• Damaged connectors

---

Repair a Short to Ground

If the signal circuit is shorted to ground, locate and repair the damaged wiring.

---

Repair a Short to Voltage

If the EGT signal circuit is contacting battery or ignition voltage, repair the wiring fault and verify the circuit again.

---

Repair or Replace the Connector

If the connector has:

• Corrosion

• Loose terminals

• Bent pins

• Heat damage

• Damaged seals

• Poor terminal tension

repair or replace it as required.

---

Correct Sensor Installation

If an incorrect EGT sensor was installed, replace it with the correct component specified for the vehicle.

---

Address Genuine Exhaust Temperature Problems

If the sensor and circuit are functioning correctly but exhaust temperature is abnormal, diagnose the underlying engine or emissions-system problem.

Possible causes include:

• Fuel-injection problems

• Misfires

• DPF regeneration faults

• Exhaust restrictions

• Turbocharger problems

• Aftertreatment faults

Replacing the EGT sensor alone will not correct a genuine exhaust-temperature problem.

---

Repair DPF Regeneration Problems

If abnormal DPF regeneration is causing an exhaust-temperature problem, diagnose the regeneration system and related components.

---

Repair Exhaust Leaks or Restrictions

Repair exhaust leaks and restrictions that affect EGT readings or exhaust operation.

---

Repair Fuel-System Problems

Correct injector, fuel-pressure, injection-timing, or combustion problems that affect exhaust temperature.

---

Repair Turbocharger Problems

If turbocharger or boost-control problems contribute to abnormal exhaust temperatures, repair the underlying problem.

---

Update Control Module Software

If the manufacturer has released a software update addressing EGT monitoring or aftertreatment operation, reprogram the applicable control module.

---

Replace the Control Module

If a confirmed internal control-module fault remains after the EGT sensor and external circuit have been tested, the relevant module may need to be replaced and programmed.

---

Clear the Code and Verify the Repair

After completing the repair:

1. Clear P2031.

2. Start the engine from a cold condition when possible.

3. Monitor Bank 1 Sensor 2 EGT data.

4. Compare the reading with other EGT sensors.

5. Verify sensor power, ground, and signal circuits.

6. Check sensor resistance or signal characteristics as applicable.

7. Monitor the EGT signal as exhaust temperature changes.

8. Check DPF regeneration status where applicable.

9. Test-drive the vehicle.

10. Rescan for stored and pending codes.

The repair should be considered successful only when the EGT sensor circuit operates normally and P2031 does not return.

---

What Happens If P2031 Is Ignored?

If the EGT sensor circuit continues to malfunction, the control module may not receive reliable information about exhaust temperature.

Possible consequences include:

• DPF regeneration problems

• Regeneration not starting

• Regeneration interruption

• Increased soot accumulation

• DPF warning

• Increased fuel consumption

• Increased emissions

• Reduced SCR efficiency

• Incorrect exhaust-temperature management

• Additional emissions-system codes

• Reduced engine power

If there is also a genuine exhaust-temperature problem, continued operation may increase the risk of damage to:

• DPF

• Catalytic converter

• Turbocharger

• Exhaust components

• Other aftertreatment components

---

Can You Drive With P2031?

Short-term driving may be possible if the vehicle operates normally, but P2031 should be diagnosed promptly.

If the problem is limited to an EGT sensor or wiring fault, the vehicle may initially drive normally.

However, continued operation with an unresolved EGT circuit malfunction can interfere with emissions-system control.

Pay particular attention to:

• DPF warning

• Reduced-power warning

• SCR warning

• Emissions countdown

• Regeneration problems

• Multiple Check Engine Light codes

• Poor engine performance

If multiple warning messages appear or the engine enters reduced-power mode, the vehicle should be inspected as soon as possible.

---

Is P2031 a Serious Code?

P2031 is generally considered a moderate-severity emissions-system fault, although its seriousness depends on the underlying cause.

A faulty EGT sensor or wiring problem does not necessarily mean that immediate engine damage is occurring.

However, EGT information can be important for DPF regeneration, catalyst monitoring, SCR operation, and exhaust thermal protection.

The fault becomes more serious if it is accompanied by:

• DPF restriction

• Failed regeneration

• High soot loading

• Genuine exhaust-temperature problems

• Fuel-system faults

• Turbocharger problems

• SCR faults

• Reduced-power warnings

The underlying cause should therefore be diagnosed rather than simply clearing the code.

---

P2031 vs. P2032 and P2033

P2031, P2032, and P2033 all concern Bank 1 Sensor 2, but they describe different fault conditions.

Code	General Meaning
P2031	EGT Sensor Circuit Malfunction – Bank 1 Sensor 2
P2032	EGT Sensor Circuit Low – Bank 1 Sensor 2
P2033	EGT Sensor Circuit High – Bank 1 Sensor 2

The distinction is important.

P2031 indicates a general malfunction in the EGT sensor circuit.

P2032 specifically indicates that the control module sees a signal below the expected range.

P2033 specifically indicates that the control module sees a signal above the expected range.

Therefore:

P2031 → Bank 1 Sensor 2 / circuit malfunction

P2032 → Bank 1 Sensor 2 / circuit low

P2033 → Bank 1 Sensor 2 / circuit high

These codes should not be treated as proof that the exhaust temperature itself is low or high.

---

P2031 vs. P2034

P2031 and P2034 identify general EGT circuit malfunctions involving different sensor locations.

Code	General Meaning
P2031	EGT Sensor Circuit Malfunction – Bank 1 Sensor 2
P2032	EGT Sensor Circuit Low – Bank 1 Sensor 2
P2033	EGT Sensor Circuit High – Bank 1 Sensor 2
P2034	EGT Sensor Circuit Malfunction – Bank 2 Sensor 2

Therefore:

P2031 → Bank 1 Sensor 2 / general circuit malfunction

P2034 → Bank 2 Sensor 2 / general circuit malfunction

If both P2031 and P2034 are present, this may indicate that more than one EGT sensor circuit is affected, although the exact diagnosis depends on the vehicle.

---

P2031 vs. P2035 and P2036

P2035 and P2036 concern Bank 2 Sensor 2.

Code	General Meaning
P2031	EGT Sensor Circuit Malfunction – Bank 1 Sensor 2
P2035	EGT Sensor Circuit Low – Bank 2 Sensor 2
P2036	EGT Sensor Circuit High – Bank 2 Sensor 2

The bank and sensor designation should always be verified before replacing a component.

---

P2031 vs. P2084–P2087

Other EGT-related codes identify different types of problems involving Sensor 2.

Code	General Meaning
P2031	EGT Sensor Circuit Malfunction – Bank 1 Sensor 2
P2084	EGT Sensor Circuit Range / Performance – Bank 1 Sensor 2
P2085	EGT Sensor Circuit Intermittent – Bank 1 Sensor 2
P2086	EGT Sensor Circuit Range / Performance – Bank 2 Sensor 2
P2087	EGT Sensor Circuit Intermittent – Bank 2 Sensor 2

This distinction is useful when multiple EGT codes are stored.

P2031 → Bank 1 Sensor 2 / general circuit malfunction

P2084 → Bank 1 Sensor 2 / range or performance

P2085 → Bank 1 Sensor 2 / intermittent

P2086 → Bank 2 Sensor 2 / range or performance

P2087 → Bank 2 Sensor 2 / intermittent

---

How to Prevent P2031

Not every EGT sensor failure can be prevented, but proper maintenance can reduce the likelihood of sensor and wiring problems.

Recommended practices include:

• Inspect EGT sensor wiring during routine servicing.

• Keep EGT wiring away from excessive exhaust heat.

• Secure wiring harnesses correctly.

• Repair melted insulation promptly.

• Inspect connectors for corrosion and moisture.

• Address exhaust leaks quickly.

• Maintain the DPF according to manufacturer recommendations.

• Do not ignore DPF regeneration warnings.

• Address fuel-injection problems promptly.

• Repair engine misfires as soon as possible.

• Maintain the turbocharger and boost-control system.

• Avoid unnecessary exhaust modifications.

• Use the correct replacement EGT sensor.

• Inspect EGT wiring after exhaust or underbody repairs.

• Address Check Engine Light and emissions-system warnings promptly.

---

Final Thoughts

P2031 Exhaust Gas Temperature (EGT) Sensor Circuit Malfunction (Bank 1 Sensor 2) indicates that the vehicle's control module has detected a malfunction in the EGT sensor circuit associated with Bank 1 Sensor 2.

Unlike P2032 and P2033, P2031 does not specifically identify a low or high electrical signal. It is a broader circuit-malfunction code.

Possible causes include:

• Faulty EGT sensor

• Open circuit

• Short circuit

• Short to ground

• Short to voltage

• Damaged wiring

• Melted insulation

• Corroded connector

• Loose terminals

• Poor electrical connections

• Incorrect sensor resistance

• Sensor contamination

• Incorrect sensor installation

• Reference or supply-voltage problems

• Exhaust heat damage

• DPF regeneration problems

• Exhaust leaks or restrictions

• Fuel-system problems

• Turbocharger problems

• Aftertreatment faults

• Control-module problems

The correct diagnostic approach is to inspect the sensor and complete electrical circuit rather than immediately replacing the sensor.

A cold-engine live-data check, visual inspection, connector inspection, continuity testing, voltage testing, resistance testing, and comparison with other EGT sensors can help identify the problem.

If the electrical circuit is functioning correctly, the technician should then investigate actual exhaust operating conditions, DPF regeneration, fuel injection, turbocharger operation, exhaust restriction, and other aftertreatment systems.

The EGT sensor should not automatically be replaced simply because P2031 is stored.

Once the underlying fault has been repaired, the code should be cleared and the vehicle tested under the conditions that originally triggered P2031.

A successful repair should restore normal operation of the Bank 1 Sensor 2 EGT sensor circuit and prevent P2031 from returning.