AutoCodes – Generic – P204A

P204A Code - Reductant Pressure Sensor Circuit

Quick Answer

The Reductant Pressure Sensor, located in the Reductant Pump and Sensor Assembly, responds to pressure changes in the reductant system. Common causes include Faulty Reductant Pressure Sensor, Reductant Pressure Sensor harness is open or shorted, Reductant Pressure Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P204A indicates Reductant Pressure Sensor Circuit.
Common causes: Common causes include Faulty Reductant Pressure Sensor, Reductant Pressure Sensor harness is open or shorted, Reductant Pressure Sensor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 17,316

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 21, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P204A Description

The Reductant Pressure Sensor, located in the Reductant Pump and Sensor Assembly, responds to pressure changes in the reductant system. The Reductant Control Module supplies 5 V to the reductant pressure sensor on the 5 V reference circuit and provides a ground on the low reference circuit. The reductant pressure sensor provides a signal to the Reductant Control Module on the sensor signal circuit relative to the pressure changes in the reductant system. The Engine Control Module (ECM) is
connected to the Reductant Control Module via the Controller Area Network (CAN) bus. The Diagnostic Trouble Code (DTC) will be set when the ECM detects that the reductant pressure sensor signal is open or shorted to ground.

OBDII Code P204A - Reductant Pressure Sensor Circuit - AutoCodes.com — P204A Code - Reductant Pressure Sensor Circuit

What does this mean?

What are the Possible Causes of the DTC P204A?

Faulty Reductant Pressure Sensor
Reductant Pressure Sensor harness is open or shorted
Reductant Pressure Sensor circuit poor electrical connection

How to Fix the DTC P204A?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P204A code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P204A code?

Need more information on how to fix the P204A code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P204A code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P204A Chevrolet — Reductant Pressure Sensor Circuit
P204A Dodge — Reductant Pressure Sensor Circuit
P204A Ford — Reductant Pressure Sensor Circuit
P204A GMC — Reductant Pressure Sensor Circuit

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P204A Code

What are common symptoms of OBDII code P204A (Reductant Pressure Sensor Circuit)?

Common symptoms include reduced engine performance, poor fuel efficiency, and the illumination of the check engine light.

What are possible causes of OBDII code P204A?

Possible causes include a faulty reductant pressure sensor, damaged wiring or connectors in the sensor circuit, or issues with the reductant pressure sensor module.

How can I diagnose the cause of OBDII code P204A?

Diagnosis typically involves using a scan tool to read the code and data related to the reductant pressure sensor. Checking the sensor's wiring, connectors, and sensor module for damage or corrosion is also recommended.

Can I drive my vehicle with OBDII code P204A?

It is not recommended to drive your vehicle with this code present, as it can lead to reduced engine performance and potential damage to the emissions system.

How can I repair OBDII code P204A?

Repair options may include replacing the reductant pressure sensor, repairing damaged wiring or connectors, or replacing the reductant pressure sensor module.

Is it possible to reset OBDII code P204A without repairs?

While clearing the code using a scan tool may temporarily turn off the check engine light, the underlying issue causing the code will persist until repaired.

Can weather or driving conditions trigger OBDII code P204A?

Extreme weather conditions or driving in harsh environments may contribute to the occurrence of this code, especially if the reductant pressure sensor is exposed to contaminants or moisture.

Are there any preventative measures to avoid OBDII code P204A?

Regular inspections of the reductant pressure sensor and its components, as well as maintaining proper driving habits and avoiding harsh driving conditions, can help prevent this code from appearing.

Should I attempt to fix OBDII code P204A myself?

While some basic troubleshooting and repairs can be done by DIY enthusiasts, it is recommended to consult a professional mechanic for a proper diagnosis and repair of OBDII code P204A to ensure safety and effectiveness.