P0473 – Exhaust Pressure Sensor High

The P0473 code is a generic powertrain/engine diagnostic trouble code that indicates an issue with the exhaust pressure sensor circuit. Specifically, it denotes that the Exhaust Pressure Sensor "A" Circuit is detecting a high input signal.

Urgency Assessment

The P0473 code is generally not considered an immediately critical issue. While it may affect vehicle performance, it does not typically pose an immediate safety risk. Drivers can usually continue operating the vehicle, but should have it inspected and repaired as soon as possible to prevent potential damage to the exhaust system or decreased fuel efficiency.

Technical Description

The P0473 code is triggered when the Powertrain Control Module (PCM) detects a voltage reading from the exhaust pressure sensor that is higher than the expected range. This sensor monitors pressure in the exhaust system, which is crucial for optimizing engine performance and emissions control, particularly in turbocharged and diesel engines.

Applicability

P0473 is a generic OBD-II code, applicable to various vehicle makes and models equipped with exhaust pressure sensors. It's commonly found in:

• Ford trucks with 6.0L diesel engines (2005 onwards)
• All Ford EcoBoost engines
• Cummins 6.7L engines (2007 onwards)
• Mercedes 3.0L engines (2007 onwards)
• Nissan pickups with Cummins 3.0L 6-cylinder engines (2015 onwards)

Components Involved

The primary components associated with the P0473 code are:

1. Exhaust Pressure Sensor: Measures pressure in the exhaust system
2. Wiring and connectors: Carry the sensor signal to the PCM
3. Powertrain Control Module (PCM): Interprets sensor data and manages engine operation

The exhaust pressure sensor plays a crucial role in engine management, particularly for vehicles with variable nozzle turbochargers and diesel particulate filters (DPF).

Common Causes

The most frequent reasons for triggering the P0473 code include:

1. Faulty exhaust pressure sensor
2. Damaged or corroded wiring in the sensor circuit
3. Loose or damaged connectors
4. Short circuit to voltage in the signal wire
5. PCM malfunction (rare)

Diagnostic Procedure

To diagnose the P0473 code, follow these steps:

1. Use an OBD-II scanner to confirm the P0473 code and check for any related codes.
2. Inspect the exhaust pressure sensor and its wiring for visible damage or corrosion.
3. Check the sensor's ground connection using a multimeter.
4. Measure the voltage at the sensor connector with the ignition on. It should be within the manufacturer's specified range (typically 0.5-4.5V).
5. Use an oscilloscope to check for abnormal voltage patterns in the sensor signal.
6. If all tests pass, consider replacing the exhaust pressure sensor.

Solutions

Depending on the diagnosis, solutions may include:

1. Replacing the faulty exhaust pressure sensor
2. Repairing or replacing damaged wiring
3. Cleaning or replacing corroded connectors
4. Updating PCM software (if applicable)
5. In rare cases, replacing the PCM

Prevention

To prevent future occurrences of the P0473 code:

1. Regularly inspect exhaust system components for damage or corrosion
2. Ensure proper maintenance of the engine and exhaust system
3. Use high-quality replacement parts when repairs are needed
4. Avoid exposure to extreme environmental conditions that could damage sensors or wiring

Repair Costs

Estimated repair costs for the P0473 code:

• Diagnostic fee: $75-$150 (€63-€126)
• Exhaust pressure sensor replacement: $150-$300 (€126-€252)
• Wiring repair: $100-$300 (€84-€252)
• PCM replacement (if necessary): $500-$1000 (€420-€840)

Labor costs may vary depending on the vehicle make and model.

Related Issues

The P0473 code often appears alongside other exhaust pressure sensor-related codes:

• P0470: Exhaust Pressure Sensor "A" Circuit
• P0471: Exhaust Pressure Sensor "A" Circuit Range/Performance
• P0472: Exhaust Pressure Sensor "A" Circuit Low
• P0474: Exhaust Pressure Sensor "A" Circuit Intermittent

Technical Specifications

Normal operating ranges for exhaust pressure sensors vary by vehicle, but typically fall within:

• Voltage range: 0.5-4.5V
• Pressure range: 0-500 kPa (0-72.5 psi)

Engineers and mechanics should always consult manufacturer-specific data for precise specifications and diagnostic procedures.

Frequently Asked Questions About P0473

What does the P0473 code mean?

P0473 indicates an “Exhaust Pressure Sensor ‘A’ Circuit High” condition, meaning the engine control module has detected a higher than expected voltage from the exhaust pressure sensor.

How urgent is it to address a P0473 code?

While not immediately critical, it’s advisable to have the issue checked soon to prevent potential damage to the exhaust system or decreased fuel efficiency.

What are the common symptoms of a P0473 code?

Common symptoms include illuminated check engine light, reduced engine performance, and potentially difficulties with exhaust system regeneration in diesel vehicles.

Is P0473 a generic or manufacturer-specific code?

P0473 is a generic OBD-II code applicable to various vehicle makes and models, particularly those with turbocharged engines.

Which vehicles commonly experience the P0473 code?

This code is often seen in Ford trucks with 6.0L diesel engines, Ford EcoBoost engines, Cummins 6.7L engines, and some Mercedes and Nissan models with diesel engines.

What components are involved with the P0473 code?

The main components are the exhaust pressure sensor, its wiring and connectors, and the Powertrain Control Module (PCM).

What are the most common causes of a P0473 code?

Common causes include a faulty exhaust pressure sensor, damaged wiring or connectors, short circuits, and rarely, PCM issues.

How is the P0473 code diagnosed?

Diagnosis typically involves using an OBD-II scanner, visually inspecting wiring and connectors, testing the sensor’s voltage output, and checking for related codes.

Can I continue driving with a P0473 code?

While you can usually continue driving, it’s best to have the issue addressed soon to prevent potential damage or decreased performance.

How is a P0473 code typically repaired?

Repairs may involve replacing the exhaust pressure sensor, repairing damaged wiring, cleaning connectors, or in rare cases, updating or replacing the PCM.

What’s the difference between P0473 and P0471 codes?

P0473 indicates a high circuit issue, while P0471 relates to a range/performance problem with the exhaust pressure sensor.

Can a P0473 code cause damage to my vehicle if left unaddressed?

While not immediately damaging, ignoring the code could lead to decreased fuel efficiency and potential exhaust system issues over time.

How much does it typically cost to repair a P0473 code?

Repair costs can vary widely depending on the cause, but typically range from $150 to $500 for sensor replacement or wiring repairs.

Can I clear the P0473 code myself?

While you can clear the code with an OBD-II scanner, it will likely return if the underlying issue isn’t addressed.

Are there any preventive measures to avoid a P0473 code?

Regular maintenance of your exhaust system and careful handling of electrical components can help prevent this issue.

Can a P0473 code affect my vehicle’s emissions?

Yes, it can potentially affect emissions control, especially in diesel vehicles with particulate filters.

Is the P0473 code related to the EGR system?

While not directly related, the exhaust pressure sensor and EGR system are both part of the exhaust management system and can sometimes be confused.

Can extreme weather conditions trigger a P0473 code?

Extreme temperatures or moisture can potentially affect sensor readings or wiring, possibly triggering this code.

How long does it typically take to diagnose and repair a P0473 code?

Diagnosis usually takes 1-2 hours, while repairs can take 2-4 hours depending on the specific issue.

Can a P0473 code cause my vehicle to fail an emissions test?

Yes, since it relates to the exhaust system, a P0473 code could potentially cause a vehicle to fail an emissions test.