AutoCodes – RAM – P203B RAM

P203B RAM Code - Reductant Level Sensor Circuit Range/Performance

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: P203B RAM indicates Reductant Level Sensor Circuit Range/Performance.
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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 818

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
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P203B RAM 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. The Diagnostic Trouble Code (DTC) will be set when the ECM receives a serial data message from the reductant sensor module that the reductant level sensor indications are not plausible.

OBDII Code P203B RAM - Reductant Level Sensor Circuit Range/Performance - AutoCodes.com — P203B RAM Code - Reductant Level Sensor Circuit Range/Performance

What does this mean?

What are the Possible Causes of the DTC P203B RAM?

Faulty Reductant Level Sensor
Reductant Level Sensor harness is open or shorted
Reductant Level Sensor circuit poor electrical connection
Faulty DEF Supply Pump Assembly
Faulty Diesel Exhaust Fluid Dosing Control Unit

How to Fix the DTC P203B RAM?

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 P203B RAM 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 P203B RAM code?

Need more information on how to fix the P203B RAM code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P203B RAM code diagnosed by a professional: Find a repair shop in your area

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 P203B RAM Code

1. What are the common symptoms of OBDII code P203B related to the Reductant Level Sensor Circuit?

The common symptoms include the Check Engine Light (CEL) illuminating on the dashboard, reduced engine performance, and potential difficulties with passing emissions tests.

2. What are the possible causes of OBDII code P203B indicating an issue with the Reductant Level Sensor Circuit?

Possible causes include a faulty reductant level sensor, damaged wiring or connectors in the sensor circuit, issues with the reductant tank, or a malfunctioning Engine Control Module (ECM).

3. How can I diagnose the OBDII code P203B linked to the Reductant Level Sensor Circuit issue?

Diagnosis involves using an OBDII scanner to retrieve the specific fault code, conducting a visual inspection of the sensor and its wiring, checking the reductant tank for any leaks or damage, and performing circuit tests to pinpoint the exact cause.

4. Can a DIY enthusiast repair the OBDII code P203B problem associated with the Reductant Level Sensor Circuit?

While some basic troubleshooting like checking connectors and wiring can be done by DIY enthusiasts, diagnosing and repairing issues with the reductant level sensor circuit may require advanced diagnostic tools and expertise, so professional assistance is recommended.

5. What are the potential repair options for resolving OBDII code P203B indicating a Reductant Level Sensor Circuit fault?

Repair options may include replacing the reductant level sensor, repairing damaged wiring or connectors, fixing issues with the reductant tank, or reprogramming the ECM if necessary.

6. Is it safe to continue driving with OBDII code P203B related to the Reductant Level Sensor Circuit issue?

It is generally not recommended to continue driving with this fault code present, as it can lead to decreased fuel efficiency, increased emissions, and potential damage to other components in the exhaust system.

7. How much does it typically cost to repair OBDII code P203B caused by a Reductant Level Sensor Circuit problem?

The cost of repair can vary depending on the exact cause of the issue, but it may range from a few hundred to a few thousand dollars, including parts and labor.

8. Are there any preventive maintenance tips to avoid encountering OBDII code P203B due to Reductant Level Sensor Circuit issues?

Regularly checking the reductant level sensor, inspecting the wiring for any signs of wear or damage, and ensuring the reductant tank is in good condition can help prevent issues related to this fault code.

9. Can resetting the Check Engine Light manually clear OBDII code P203B associated with the Reductant Level Sensor Circuit?

Resetting the Check Engine Light may temporarily clear the code, but if the underlying issue with the Reductant Level Sensor Circuit is not addressed, the code is likely to reappear after some driving cycles.

10. Does the OBDII code P203B related to the Reductant Level Sensor Circuit impact vehicle safety?

While this fault code may not directly affect the safety of the vehicle, ignoring the underlying issue can lead to reduced engine performance, increased emissions, and potential long-term damage to the exhaust system, so it is best to address it promptly.