P143A 2018 GMC Sierra Code - Reductant Control System Diagnostic Signal Message Counter Incorrect
Quick Answer
The P143A diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates a problem with the Reductant Control System Diagnostic Signal Message Counter being incorrect. Common causes include Faulty Reductant Control Module, Malfunctioning Reductant Injector, Wiring or connection issues within the Reductant Control System. 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
- P143A 2018 GMC Sierra indicates Reductant Control System Diagnostic Signal Message Counter Incorrect.
- Common causes
- Common causes include Faulty Reductant Control Module, Malfunctioning Reductant Injector, Wiring or connection issues within the Reductant Control System.
- 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 P143A 2018 GMC Sierra Description
The P143A diagnostic trouble code (DTC) for a 2018 GMC Sierra indicates a problem with the Reductant Control System Diagnostic Signal Message Counter being incorrect. The Reductant Control System is a crucial component of the vehicle's emissions control system, specifically designed to reduce harmful emissions. This system utilizes a reductant, typically a urea-based solution known as Diesel Exhaust Fluid (DEF), to break down nitrogen oxides into harmless nitrogen and water vapor through a process called Selective Catalytic Reduction (SCR).
Common Causes of P143A 2018 GMC Sierra
- Faulty Reductant Control Module
- Malfunctioning Reductant Injector
- Wiring or connection issues within the Reductant Control System
- Low DEF fluid level or contaminated DEF
- Software or calibration issues within the vehicle's onboard computer
Symptoms of P143A 2018 GMC Sierra
- Check engine light illuminated
- Reduced fuel efficiency
- Failed emissions test
- Rough idling or hesitation during acceleration
- Increased exhaust emissions
How to Fix P143A 2018 GMC Sierra
- Use a diagnostic scan tool to retrieve the specific DTC and freeze frame data related to the P143A code.
- Inspect the Reductant Control System components, including the module, injector, wiring, and connections, for any visible damage or corrosion.
- Test the Reductant Control Module and Injector for proper functionality using a multimeter or oscilloscope.
- Verify the DEF fluid level and quality, ensuring it meets the manufacturer's specifications.
- Clear the DTC and reset the vehicle's onboard computer to see if the issue persists after repairs have been made.
Cost to Fix P143A 2018 GMC Sierra
The cost of repairing a P143A code on a 2018 GMC Sierra can vary depending on the specific cause of the issue. In general, the parts required for this repair, such as a new Reductant Control Module or Injector, can range from $200 to $500. Labor costs at an auto repair shop typically range from $80 to $150 per hour, with the total repair bill potentially amounting to $300 to $800 or more. It is advisable to consult with a trusted mechanic or dealership to get an accurate estimate based on the vehicle's condition and the required repairs.
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Frequently Asked Questions about P143A 2018 GMC Sierra Code
1. What does the OBDII code P143A mean on a 2018 GMC Sierra?
P143A indicates an issue with the Reductant Control System, where the diagnostic signal message counter is incorrect, often related to the diesel exhaust fluid (DEF) system.
2. What are the common symptoms of code P143A in a 2018 GMC Sierra?
Symptoms may include an illuminated check engine light, DEF system warnings, reduced engine power, or the vehicle entering limp mode.
3. What causes the P143A code to appear in a GMC Sierra?
Common causes include a malfunctioning reductant control module, corrupted or mismatched communication signals, wiring issues, or software glitches in the DEF system.
4. Can a P143A code affect vehicle performance?
Yes, it can lead to reduced engine power or a limp mode condition, which limits the vehicle’s performance to encourage immediate repair.
5. How is the P143A code diagnosed?
Diagnosis typically involves scanning for stored codes, inspecting the reductant control module and its wiring, and testing the communication between the control module and ECM.
6. Is it safe to drive with a P143A code on a 2018 GMC Sierra?
While the vehicle may still be drivable initially, continued operation can lead to more severe DEF system issues or further performance limitations.
7. How can the P143A code be fixed on a GMC Sierra?
Repairs may include reprogramming or replacing the reductant control module, fixing wiring or connection issues, or performing a software update for the ECM.
8. Does the P143A code require diesel exhaust fluid to be checked?
Not directly, but ensuring the DEF system is functioning properly and the fluid is filled can help prevent related issues.
9. Can a software update resolve the P143A code?
Yes, in some cases, a software update for the ECM or reductant control module may resolve the issue if it’s caused by a programming glitch.
10. How much does it typically cost to repair a P143A code on a 2018 GMC Sierra?
Repair costs vary but can range from $100 to $1,000, depending on whether the issue is related to wiring, module replacement, or a software update.
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