AutoCodes – Generic – P204D

P204D Code - Reductant Pressure Sensor Circuit High

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: P204D indicates Reductant Pressure Sensor Circuit High.
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 8,710

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
Comments
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Code P204D 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 P204D - Reductant Pressure Sensor Circuit High - AutoCodes.com — P204D Code - Reductant Pressure Sensor Circuit High

What does this mean?

What are the Possible Causes of the DTC P204D?

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 P204D?

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 P204D 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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Information for Specific Makes

P204D Buick — Reductant Pressure Sensor Circuit High
P204D Cadillac — Reductant Pressure Sensor Circuit High
P204D Chevrolet — Reductant Pressure Sensor Circuit High
P204D Dodge — Reductant Pressure Sensor Circuit High
P204D Ford — Reductant Pressure Sensor Circuit High
P204D GMC — Reductant Pressure Sensor Circuit High

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.