P143A 2018 GMC Sierra Code - Reductant Control System Diagnostic Signal Message Counter Incorrect
Quick Answer
Control modules connected to the serial data circuits monitor the communication during normal vehicle operation. Common causes include Faulty 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 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.
Code P143A 2018 GMC Sierra Description
What are the Possible Causes of the DTC P143A 2018 GMC Sierra?
- Faulty Reductant Control System
How to Fix the DTC P143A 2018 GMC Sierra?
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 P143A 2018 GMC Sierra 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 P143A 2018 GMC Sierra code?
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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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