AutoCodes – Generic – P249C

P249C Code - Excessive Time To Enter Closed Loop Reductant Injection Control

Quick Answer

Some manufacturers are now using a Diesel Exhaust Fluid (DEF) system commonly called a Selective Catalytic Reduction (SCR) system to reduce harmful Oxides of Nitrogen (NOx). Common causes include Exhaust Leaks, Fuel contamination, Faulty Diesel Particulate Filter (DPF). 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: P249C indicates Excessive Time To Enter Closed Loop Reductant Injection Control.
Common causes: Common causes include Exhaust Leaks, Fuel contamination, Faulty Diesel Particulate Filter (DPF).
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 10,941

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 Jul 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P249C Description

Some manufacturers are now using a Diesel Exhaust Fluid (DEF) system commonly called a Selective Catalytic Reduction (SCR) system to reduce harmful Oxides of Nitrogen (NOx). The diesel exhaust fluid is a Urea based solution of approximately 32% Urea and 64% distilled water. The solution is injected into the exhaust gas stream upstream of the SCR catalyst. Once in the exhaust system it decomposes and becomes Ammonia (NH3) and Carbon dioxide (CO2). Within the catalyst, the NH3 and CO2 react with the Nox to create Oxygen (O2) and harmless Nitrogen (N2).
The system requires a storage tank for the diesel exhaust fluid, a pump with integrated level sensor, pressure sensor and fluid quality sensor, an injector fitted to the exhaust system, fluid heater and the catalyst. Sensors can also be fitted close to the SCR catalyst to monitor temperature during regeneration.
The system is closely monitored for correct operation as failure of the system will have a large impact on vehicle exhaust gas emissions of oxides of Nitrogen.

OBDII Code P249C - Excessive Time To Enter Closed Loop Reductant Injection Control - AutoCodes.com — P249C Code - Excessive Time To Enter Closed Loop Reductant Injection Control

What does this mean?

What are the Possible Causes of the DTC P249C?

Exhaust Leaks
Fuel contamination
Faulty Diesel Particulate Filter (DPF)
Faulty NOx Sensor
Diesel Exhaust Fluid
Faulty Selective Catalyst Reduction (SCR) Catalyst

How to Fix the DTC P249C?

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 P249C 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 P249C code?

Need more information on how to fix the P249C code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P249C code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P249C Ford — Excessive Time To Enter Closed Loop Reductant Injection Control
P249C Mercedes-Benz — Excessive Time To Enter Closed Loop Reductant Injection Control

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 P249C Code

1. What are the common symptoms of OBDII code P249C?

- Common symptoms include the check engine light coming on, reduced engine performance, and potential issues with emissions.

2. What does OBDII code P249C indicate?

- OBDII code P249C indicates that there is excessive time taken to enter closed loop reductant injection control, typically related to the diesel exhaust fluid (DEF) system.

3. What are the possible causes of OBDII code P249C?

- Possible causes include a faulty reductant injector, issues with the reductant pump, wiring or connector problems, low DEF fluid levels, or a malfunctioning control module.

4. How can I diagnose OBDII code P249C?

- Diagnosis typically involves using a scan tool to read the code, checking the DEF system components for any visible damage or leaks, and performing tests to pinpoint the exact cause.

5. Can I still drive my vehicle with OBDII code P249C?

- It is generally not recommended to drive the vehicle with this code present, as it can lead to decreased fuel efficiency and potential damage to the emissions system.

6. How can I repair OBDII code P249C?

- Repair options may include replacing the faulty reductant injector or pump, repairing wiring or connectors, refilling DEF fluid, or reprogramming the control module.

7. Is OBDII code P249C a serious issue?

- While it may not cause immediate harm to the vehicle, it is important to address this code promptly to ensure proper emissions control and engine performance.

8. Can a DIY enthusiast fix OBDII code P249C?

- Depending on the underlying cause, some DIY enthusiasts with the necessary tools and knowledge may be able to address this code themselves, but professional assistance is recommended for complex issues.

9. How much does it cost to repair OBDII code P249C?

- The cost of repairs can vary widely depending on the specific cause of the code and whether parts need to be replaced or repaired. It is advisable to obtain quotes from reputable mechanics or dealerships.

10. How can I prevent OBDII code P249C from recurring?

- Regularly maintaining the DEF system, checking fluid levels, and addressing any issues promptly can help prevent the recurrence of OBDII code P249C.