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

Urgency and Severity

The P0547 code indicates a problem with the exhaust gas temperature (EGT) sensor circuit for bank 2, sensor 1. While this code does not usually cause immediate drivability issues, it can lead to increased emissions and decreased fuel efficiency over time. It is generally safe to continue driving in the short term, but the underlying issue should be diagnosed and repaired as soon as possible to prevent potential catalytic converter damage. If the check engine light is flashing, you should stop driving immediately and have the vehicle towed to avoid severe engine or emissions system damage.

Code Specifics

P0547 is a generic powertrain code that applies to all makes and models of vehicles with an OBD-II system (1996 and newer). The code definition is the same across different manufacturers, but the specific repair steps, parts, and costs can vary between makes and models.

Affected Parts and Role

The main component involved with P0547 is the exhaust gas temperature sensor located in bank 2 (cylinder bank opposite bank 1 which contains cylinder #1), sensor 1 (upstream of the catalytic converter). The EGT sensor measures the temperature of the exhaust gases coming out of the engine. This information is sent to the powertrain control module (PCM) which uses it to adjust engine timing, air-fuel ratio, and other parameters to reduce emissions and protect the catalytic converter from overheating.

Common Causes

Potential causes of a P0547 code include:

• Faulty EGT sensor
• Damaged or shorted wiring/connectors in the EGT sensor circuit
• Exhaust leaks before the EGT sensor
• Carbon buildup on the EGT sensor tip
• Defective PCM (rare)

Diagnosis Steps

To properly diagnose a P0547 code, a mechanic should:

1. Visually inspect the wiring and connectors for the EGT sensor. Repair/replace as needed.
2. Check for exhaust leaks before the EGT sensor. Repair leaks if found.
3. With the key on, engine off, use a multimeter to check for reference voltage and ground signal at the EGT sensor connector. Compare to specs.
4. Use an ohmmeter to test the resistance of the EGT sensor at various temperatures. Compare to specs.
5. If no problems are found, suspect a faulty PCM.

Repair Solutions

Fixes for a P0547 code may involve:

• Replacing the EGT sensor
• Repairing shorted, open, or damaged wiring in the EGT circuit
• Fixing exhaust leaks
• Cleaning carbon deposits from the EGT sensor tip
• Reflashing or replacing the PCM

Prevention

To prevent EGT sensor issues, ensure regular maintenance of the exhaust and emissions systems. Avoid using low quality fuel which can cause carbon buildup on the sensor. Fix exhaust leaks promptly. Regularly inspect the wiring harness for damage.

Repair Cost

The cost to diagnose and repair a P0547 code can range from $150-$500 depending on the root cause. An EGT sensor itself typically costs between $100-$300. If wiring repairs are needed, add 1-3 hours of labor at $75-$150 per hour. A PCM replacement can cost $500-$1500 if required.

By understanding the P0547 code and its causes, you can more quickly diagnose and repair the issue to restore your vehicle's performance and emissions compliance. If you're unsure about tackling this repair yourself, consult a professional mechanic for an accurate diagnosis and quality repair.

Frequently Asked Questions about the P0547 Code

What does the P0547 code mean?

The P0547 code indicates a problem with the exhaust gas temperature (EGT) sensor circuit for bank 2, sensor 1. It means the powertrain control module (PCM) has detected a malfunction in the wiring, connector, or the sensor itself.

Is it safe to drive with a P0547 code?

In most cases, you can continue driving safely in the short term with a P0547 code. However, driving with this code for an extended period can lead to increased emissions, decreased fuel efficiency, and potential catalytic converter damage. If the check engine light is flashing, stop driving immediately and have the vehicle towed.

What are the common causes of a P0547 code?

Common causes include a faulty EGT sensor, damaged wiring or connectors in the sensor circuit, exhaust leaks before the sensor, carbon buildup on the sensor tip, and in rare cases, a defective PCM.

What are the symptoms of a P0547 code?

Often there are no noticeable symptoms other than the check engine light being on. In some cases, you may experience decreased engine performance or fuel efficiency.

How do you diagnose a P0547 code?

Diagnosis steps include visually inspecting the wiring and connectors, checking for exhaust leaks, testing the sensor’s reference voltage and ground signal, and measuring the sensor’s resistance at different temperatures. If no issues are found, the PCM may be faulty.

What parts are involved with a P0547 code?

The main component is the exhaust gas temperature sensor located in the exhaust system before the catalytic converter on bank 2. The wiring harness, connectors, and PCM are also involved.

What is the role of the exhaust gas temperature sensor?

The EGT sensor measures the temperature of the exhaust gases exiting the engine. This information is sent to the PCM which uses it to adjust engine timing, air-fuel ratio, and other parameters to reduce emissions and protect the catalytic converter.

Can I replace the EGT sensor myself?

Replacing the sensor is relatively straightforward for someone with basic automotive repair skills and tools. However, proper diagnosis is important to determine if the sensor is truly at fault before replacing it.

How much does it cost to fix a P0547 code?

The cost to diagnose and repair a P0547 code ranges from $150-$500 depending on the root cause. An EGT sensor typically costs $100-$300, with labor adding 1-3 hours at $75-$150 per hour. A PCM replacement can cost $500-$1500 if needed.

Can a P0547 code cause a vehicle to fail an emissions test?

Yes, a malfunctioning EGT sensor can cause higher than normal emissions levels which may result in a failed smog check.

What should I do if I get a P0547 code?

If the code is not accompanied by a flashing check engine light or drivability issues, it’s okay to continue driving in the short term. However, have the code diagnosed and repaired as soon as possible to prevent potential damage.

How often do EGT sensors fail?

EGT sensor failures are not extremely common, but they can occur due to normal wear, excessive carbon buildup, or damage from an exhaust leak. Proper maintenance can help extend the sensor’s lifespan.

Can a P0547 code be caused by using the wrong type of fuel?

Using fuel with too low of an octane rating or contaminated fuel can cause incomplete combustion which may lead to excessive carbon buildup on the EGT sensor over time. Always use the recommended fuel grade for your vehicle.

Will clearing the P0547 code fix the problem?

No, clearing the code without repairing the underlying cause will only temporarily turn off the check engine light. The code will reappear once the PCM detects the fault again after some driving.

How do I prevent EGT sensor issues?

Regular maintenance of the exhaust and emissions systems, using high quality fuel, promptly fixing exhaust leaks, and regularly inspecting the wiring harness can help prevent EGT sensor problems.

Are there any recalls or TSBs related to the P0547 code?

Recalls and technical service bulletins (TSBs) related to the P0547 code are rare and vary by vehicle make and model. Check with your local dealer to see if there are any for your specific vehicle.

Can aftermarket exhaust modifications cause a P0547 code?

Yes, installing an aftermarket exhaust system, especially one without a catalytic converter, can cause changes in exhaust back pressure which may trigger a P0547 code. Some tuners install an inline resistor to prevent this.

What other codes may appear along with P0547?

Related codes that may appear include P0546 (EGT sensor circuit range/performance), P2031 (EGT sensor circuit low input), P2032 (EGT sensor circuit high input), and P2033 (EGT sensor circuit intermittent).

Is a P0547 code the same for all vehicle makes and models?

The generic definition of the P0547 code is the same for all vehicles equipped with OBD-II (1996 and newer). However, the specific repair procedures, parts, and costs can vary between different makes and models.

When should I consider replacing my vehicle if I keep getting a P0547 code?

If the P0547 code keeps returning after multiple professional repairs have been attempted, it may be a sign of a more serious issue with the exhaust or emissions system. Consider the age, overall condition, and value of the vehicle when deciding whether to continue investing in repairs or replace it.