AutoCodes – Cadillac – P204C Cadillac

P204C Cadillac Code - Reductant Pressure Sensor Circuit Low

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 Pump and Sensor Assembly, Reductant Pump and Sensor Assembly harness is open or shorted, Reductant Pump and Sensor Assembly 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: P204C Cadillac indicates Reductant Pressure Sensor Circuit Low.
Common causes: Common causes include Faulty Reductant Pump and Sensor Assembly, Reductant Pump and Sensor Assembly harness is open or shorted, Reductant Pump and Sensor Assembly 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 343

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 P204C Cadillac 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 P204C Cadillac - Reductant Pressure Sensor Circuit Low - AutoCodes.com — P204C Cadillac Code - Reductant Pressure Sensor Circuit Low

What does this mean?

What are the Possible Causes of the DTC P204C Cadillac?

Faulty Reductant Pump and Sensor Assembly
Reductant Pump and Sensor Assembly harness is open or shorted
Reductant Pump and Sensor Assembly circuit poor electrical connection
Faulty Reductant Control Module

How to Fix the DTC P204C Cadillac?

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 P204C Cadillac 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.

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Need Help with the Code?

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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 P204C Cadillac Code

1. What does the OBDII code P204C Cadillac indicate?

The code P204C for Cadillac refers to a fault in the Reductant Pressure Sensor Circuit, specifically indicating a low pressure reading.

2. What are the common symptoms of the P204C code in a Cadillac vehicle?

Common symptoms of the P204C code in a Cadillac may include poor engine performance, reduced fuel efficiency, and the illumination of the check engine light.

3. What are the possible causes of the P204C Cadillac trouble code?

Potential causes of the P204C code in a Cadillac include a faulty reductant pressure sensor, wiring issues in the sensor circuit, or a problem with the powertrain control module (PCM).

4. How can I diagnose the P204C code in my Cadillac?

Diagnosing the P204C code in a Cadillac typically involves using an OBDII scanner to read the code, inspecting the reductant pressure sensor and its wiring, and testing the sensor's functionality.

5. What are the repair options for fixing the P204C code in a Cadillac?

Repair options for addressing the P204C code in a Cadillac may include replacing the faulty reductant pressure sensor, repairing any damaged wiring, or resetting the PCM after fixing the issue.

6. Can I continue driving my Cadillac with the P204C trouble code?

While it may be possible to drive the vehicle with the P204C code, it is not recommended as it can lead to further engine issues and potential damage. It's best to address the problem promptly.

7. Is the repair for the P204C code in a Cadillac considered complex?

The complexity of repairing the P204C code in a Cadillac can vary depending on the exact cause of the issue. In some cases, it may require professional diagnosis and repair.

8. Are there any preventive maintenance tips to avoid the P204C trouble code in a Cadillac?

To potentially prevent the P204C code in a Cadillac, regular maintenance checks, such as inspecting the reductant system components and keeping up with scheduled services, can be helpful.

9. Can a DIY enthusiast fix the P204C code in a Cadillac themselves?

Depending on the individual's skill level and access to tools, some DIY enthusiasts may be able to address the P204C code in a Cadillac themselves by following repair guides or seeking assistance.

10. Does the P204C code in a Cadillac affect emissions or vehicle compliance?

The P204C code in a Cadillac may impact emissions levels and could potentially lead to compliance issues during vehicle inspections. It's crucial to address the problem promptly to maintain compliance.