AutoCodes – Generic – P203D

P203D Code - Reductant Level Sensor Circuit High

Quick Answer

The Diesel Exhaust Fluid (DEF) Tank Level Sensor and Diesel Exhaust Fluid (DEF) Tank Temperature Sensor are to measure the level and temperature of the fluid inside the DEF Tank. Common causes include Faulty Reductant Level Sensor, Reductant Level Sensor harness is open or shorted, Reductant Level 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: P203D indicates Reductant Level Sensor Circuit High.
Common causes: Common causes include Faulty Reductant Level Sensor, Reductant Level Sensor harness is open or shorted, Reductant Level 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 27,958

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 Dec 23, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P203D Description

The Diesel Exhaust Fluid (DEF) Tank Level Sensor and Diesel Exhaust Fluid (DEF) Tank Temperature Sensor are to measure the level and temperature of the fluid inside the DEF Tank. Though integrated with the DEF Supply Pump the level sensor and the temperature sensor operate independently. The temperature sensor operates as a typical two wire 5-Volt sensor. The level sensor operates as a typical three wire 5-Volt sensor. The DEF Tank Temperature Sensor is a negative temperature coefficient sensor. The sensors are not sold separately and must be replaced with the DEF Supply Pump assembly. The DEF Dosing Control Unit monitors these inputs and reports them to the Powertrain Control Module (PCM). The PCM will illuminate the MIL lamp after this diagnostic runs and fails for two consecutive trips. The PCM will turn off the MIL lamp immediately after the diagnostic runs and passes. Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.

OBDII Code P203D - Reductant Level Sensor Circuit High - AutoCodes.com — P203D Code - Reductant Level Sensor Circuit High

What does this mean?

What are the Possible Causes of the DTC P203D?

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

How to Fix the DTC P203D?

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 P203D 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

P203D Audi — Reductant Level Sensor Circuit High
P203D BMW — Reductant Level Sensor Circuit High
P203D Buick — Reductant Level Sensor Circuit High Voltage
P203D Cadillac — Reductant Level Sensor Circuit High Voltage
P203D Chevrolet — Reductant Level Sensor Circuit High Voltage
P203D Dodge — Reductant Level Sensor Circuit High
P203D Ford — Reductant Level Sensor Circuit High
P203D GMC — Reductant Level Sensor Circuit High Voltage
P203D Mercedes-Benz — Reductant Level Sensor Circuit High
P203D RAM — Reductant Level Sensor Circuit High
P203D Volkswagen — Reductant Level 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.