P0547 Exhaust Gas Temperature (EGT) Sensor Circuit (Bank 2, Sensor 1)

The P0547 trouble code means the engine control module has detected a problem in the electrical circuit of the Exhaust Gas Temperature (EGT) Sensor on Bank 2, Sensor 1.

The EGT sensor measures the temperature of exhaust gases and sends this information to the engine control module. This information can be important for protecting the engine and exhaust system, particularly the turbocharger, catalytic converter, DPF, and other emissions components.

Unlike P0548 (Circuit Low) and P0549 (Circuit High), P0547 is a more general circuit fault. The code tells you that the control module has identified a problem with this particular EGT sensor circuit, but it does not specify whether the signal is too high, too low, open, intermittent, or caused by the sensor itself.

Therefore, P0547 should be treated as a starting point for diagnosis rather than a direct instruction to replace the EGT sensor.

What Is the EGT Sensor?

The Exhaust Gas Temperature sensor is designed to monitor the temperature of exhaust gases.

Depending on the engine, EGT information can be used to protect and control:

• Turbocharger

• Catalytic converter

• Diesel oxidation catalyst

• Diesel particulate filter

• Exhaust manifold

• Exhaust valves

• Emissions-control systems

The sensor converts exhaust temperature into an electrical signal that the control module can interpret.

As exhaust temperature changes, the sensor's electrical characteristics also change. The control module uses this information to calculate the approximate exhaust temperature.

What Do Bank 2 and Sensor 1 Mean?

Bank 2 refers to the cylinder bank that does not contain cylinder number 1.

This terminology applies primarily to engines with two cylinder banks, such as:

• V6

• V8

• V10

• V12

Sensor 1 generally refers to the sensor positioned upstream in the exhaust system, closer to the engine.

Depending on the engine design, Bank 2 Sensor 1 may be installed:

• In the exhaust manifold

• Before the turbocharger

• Near the turbocharger

• In an upstream exhaust pipe

The exact position varies between vehicles, so the manufacturer's wiring diagram and component-location information should be used.

What Does P0547 Actually Tell You?

P0547 tells you that the control module has detected a problem with the EGT Sensor Bank 2 Sensor 1 circuit.

It does not tell you that the sensor itself has failed.

The problem could be caused by:

• Failed EGT sensor

• Open circuit

• Short circuit

• Damaged signal wire

• Damaged power or reference circuit

• Poor sensor ground

• Corroded connector

• Loose terminal

• Heat-damaged wiring

• Incorrect sensor

• Internal control-module problem

The actual exhaust temperature should also be considered if the sensor appears to be functioning electrically.

Symptoms of P0547

The symptoms vary according to the vehicle and the role of the EGT sensor in its engine-management strategy.

Possible symptoms include:

• Check Engine Light

• Reduced engine performance

• Limp-home mode

• Reduced turbocharger boost

• Increased fuel consumption

• Poor acceleration

• DPF regeneration problems

• Emissions-system warning

• Additional EGT sensor codes

• Additional turbocharger or exhaust-system codes

• Cooling or exhaust-management changes

Some vehicles may have no obvious drivability symptoms at all.

In these cases, the vehicle may appear to operate normally while the control module has stored P0547 because it can no longer rely on the temperature information from the sensor.

Why Is an EGT Circuit Fault Important?

Exhaust temperatures can become extremely high under certain operating conditions.

The control module needs reliable EGT information to determine whether the exhaust system is operating within an acceptable temperature range.

If the signal from Bank 2 Sensor 1 becomes unreliable, the control module may not know the actual exhaust temperature.

This can be particularly important during:

• Heavy acceleration

• High engine load

• Turbocharger operation

• DPF regeneration

• Certain catalyst operating conditions

Depending on the vehicle, the control module may respond by changing engine operation or disabling certain functions as a protective measure.

Common Causes of P0547

Failed EGT sensor

The sensor itself can deteriorate after repeated exposure to extreme exhaust temperatures.

Internal degradation can change its electrical characteristics and cause the control module to detect an abnormal circuit condition.

Open circuit

A broken wire or disconnected sensor can interrupt the circuit.

An open circuit is especially important to consider because EGT sensors are installed in areas where wiring is exposed to high temperatures.

The sensor connector may appear physically intact while the wiring farther along the harness has been damaged by heat.

Heat-damaged wiring

This is one of the most common areas to inspect.

EGT wiring can become:

• Brittle

• Melted

• Cracked

• Burned

• Exposed

The harness should be inspected carefully around the exhaust manifold and turbocharger.

Short circuit

The signal wire may contact ground or another circuit.

A short can cause the control module to receive an implausible signal and set P0547.

Connector problems

A loose or corroded connector can interrupt or distort the sensor signal.

Check for:

• Corrosion

• Bent terminals

• Loose terminals

• Broken locking tabs

• Water contamination

• Heat damage

• Poor terminal tension

Poor sensor ground

If the sensor relies on a dedicated electrical ground, a poor ground can affect its output.

A ground connection can look physically acceptable while still producing excessive resistance under operating conditions.

Incorrect replacement sensor

EGT sensors can have different electrical characteristics.

Installing a sensor that physically fits but does not have the correct electrical characteristics can result in an incorrect signal.

The replacement part should therefore be matched to the exact vehicle and engine application.

Control-module problem

A control-module fault is possible, but it should normally be considered only after the sensor and its complete circuit have been tested.

How to Diagnose P0547

Start by scanning the vehicle for all stored and pending fault codes.

Do not diagnose P0547 in isolation.

If other EGT, turbocharger, DPF, fuel-system, exhaust, or system-voltage codes are present, they may provide important information about the underlying problem.

Freeze-frame data should also be checked if available.

This can show what the engine was doing when the control module detected the fault.

Inspect the EGT Sensor and Harness

A visual inspection is particularly important with EGT faults because of the sensor's location.

Inspect the sensor and wiring for:

• Burned insulation

• Melted wires

• Cracked insulation

• Broken wires

• Chafing

• Loose connectors

• Corrosion

• Incorrect previous repairs

• Wiring touching the exhaust

• Signs of excessive heat

Do not stop at the sensor connector.

Follow the harness away from the exhaust system and inspect the entire accessible section.

Check the Electrical Circuit

The technician should identify the EGT sensor's:

• Signal circuit

• Power or reference circuit, if applicable

• Ground

• Connector terminals

The exact circuit configuration depends on the sensor design and vehicle.

The circuit should be tested using the manufacturer's wiring diagram and specifications.

There is no universal EGT sensor voltage or resistance value that applies to every vehicle.

Different EGT sensor designs can have significantly different electrical characteristics.

Check Live Data

If the diagnostic scanner provides EGT sensor data, monitor Bank 2 Sensor 1.

Compare the reading with:

• Engine coolant temperature

• Other EGT sensors

• Engine load

• Engine speed

• Intake temperature

• Operating conditions

A cold engine should not normally report an implausibly extreme exhaust temperature immediately after startup.

Likewise, an EGT value that remains fixed while operating conditions change can be a valuable clue.

However, the expected relationship between different EGT sensors depends on where each sensor is installed.

Compare the Sensor With Other EGT Sensors

If the vehicle has multiple EGT sensors, comparison can be very useful.

For example, when the engine is cold, the EGT readings should generally be consistent with the actual thermal conditions of the exhaust system.

As the engine warms and load changes, the readings should respond in a logical manner.

If Bank 2 Sensor 1 behaves very differently from the other sensors, further electrical and sensor testing is justified.

This does not prove that the sensor is defective, but it helps identify where the problem is occurring.

P0547 Does Not Automatically Mean the Exhaust Is Too Hot

This distinction is important.

P0547 is a circuit fault.

The code does not directly state:

"The exhaust temperature is too high."

Instead, it states that the control module has detected a problem with the electrical circuit responsible for receiving information from the EGT sensor.

The exhaust could be at a completely normal temperature while the sensor circuit is faulty.

For example, a broken signal wire could prevent the control module from receiving a valid temperature signal even though the exhaust system itself is operating normally.

P0547 on Diesel Engines

P0547 can be particularly important on diesel engines equipped with a Diesel Particulate Filter (DPF).

The DPF regeneration process requires careful temperature management.

During regeneration, exhaust temperatures are intentionally increased to help burn accumulated soot.

The control module relies on temperature sensors to monitor this process.

If the Bank 2 Sensor 1 EGT circuit is faulty, the control module may alter or prevent certain regeneration strategies depending on the vehicle.

This can potentially lead to:

• DPF warning messages

• Failed regeneration

• Increasing soot load

• Reduced engine performance

• Additional emissions-related fault codes

The exact response depends on the manufacturer's control strategy.

P0547 on Turbocharged Engines

EGT information is also important on turbocharged engines.

High exhaust temperatures can place significant thermal stress on the turbocharger and exhaust components.

The engine control module may use EGT information together with boost pressure, engine load, airflow, fuel delivery, and engine speed.

If the EGT sensor circuit is unreliable, the module may use a protective fallback strategy.

This is one reason some vehicles can experience reduced power after an EGT-related fault appears.

Can You Drive With P0547?

It depends on the vehicle and symptoms.

If the engine runs normally and there are no additional warning messages, some vehicles may remain driveable for a limited period.

However, continued driving should not be treated as harmless simply because the vehicle still runs.

If P0547 is accompanied by:

• Reduced engine power

• Limp mode

• DPF warning

• Turbocharger problems

• Excessive exhaust smoke

• Unusual exhaust-system behavior

• Other serious engine faults

the vehicle should be diagnosed promptly.

If there is evidence of a genuine overheating exhaust condition, continuing to operate the vehicle under heavy load can potentially cause expensive damage.

P0547 vs. P0548 and P0549

These three codes concern the same general EGT sensor location but provide different information.

P0547 – EGT Sensor Circuit, Bank 2 Sensor 1

A general circuit fault has been detected.

P0548 – EGT Sensor Circuit Low, Bank 2 Sensor 1

The control module is receiving an electrical signal lower than expected.

P0549 – EGT Sensor Circuit High, Bank 2 Sensor 1

The control module is receiving an electrical signal higher than expected.

This distinction is useful when diagnosing the wiring.

For example, P0549 can direct attention toward a high-signal condition, while P0547 gives a broader indication that the circuit itself is not operating correctly.

Common Diagnostic Mistakes

The biggest mistake is assuming that the code automatically identifies a failed EGT sensor.

Other common mistakes include:

• Replacing the sensor without inspecting the wiring

• Ignoring heat damage

• Checking only the connector

• Failing to check sensor ground

• Checking resistance without considering sensor temperature

• Using generic resistance specifications

• Installing an incorrect replacement sensor

• Ignoring other EGT-related codes

• Assuming a normal exhaust temperature eliminates an electrical problem

• Replacing the ECU before testing the complete circuit

Because EGT sensors operate in an extremely hot environment, wiring inspection should receive particular attention.

The Most Important Point About P0547

P0547 means the control module has detected a fault in the Exhaust Gas Temperature sensor circuit for Bank 2, Sensor 1.

It does not automatically mean that the EGT sensor has failed, and it does not mean that the exhaust temperature is necessarily too high.

The fault can originate from the sensor, wiring, connector, power/reference circuit, ground, or another part of the exhaust-temperature monitoring system.

The most reliable diagnosis combines visual inspection, electrical testing, live EGT data, comparison with other sensors where available, and—when necessary—verification of the actual exhaust-system temperature.

Before replacing the sensor, determine whether the control module is receiving no signal, an implausible signal, or a signal that is being distorted somewhere in the circuit.