FAULTBASE
Error CodesASKCars
© 2025 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
Home/Cars/Ram/1500/DT (2019-Present)/why does my Ram 1500 DT (2019-Present) check engine light keep coming on

why does my Ram 1500 DT (2019-Present) check engine light keep coming on

Ram 1500 DT (2019-Present)

Error Codes
Severity: mediumDifficulty: mediumError Code: P04202-4 hours
3 min read
514 words

Problem Statement

Learn how to diagnose and fix the P0420 check engine light issue in a 2019 Ram 1500 DT. Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
P0420
Component
Engine
Repair Time
2-4 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems.
  • ⚠Allow the engine to cool before working on it to avoid burns.

Symptoms

  • •Check engine light illuminated
  • •Rough idle
  • •Decreased fuel efficiency
  • •Engine stalling during acceleration
  • •Unusual engine noises
  • •Increased emissions

Diagnostic Steps

  1. 1Scan for error codes using an OBD-II scanner to identify specific trouble codes.
  2. 2Inspect the gas cap for damage or improper sealing.
  3. 3Check engine oil and coolant levels to ensure they are within normal operating ranges.
  4. 4Examine the air intake system for leaks or blockages.
  5. 5Inspect the exhaust system for any signs of leaks or damage.
  6. 6Test the vehicle's battery and charging system for proper voltage and connections.

Solution

Solution

1. Preparation

  • Gather tools and parts needed for the repair.
  • Disconnect the battery's negative terminal to ensure safety while working on electrical components.

2. Address Error Codes

  • Review the OBD-II scanner codes and identify the specific issue (e.g., P0420 for catalytic converter efficiency).
  • Research the specific code to understand the likely causes and recommended repair actions.

3. Inspect and Replace Components

  • For Fuel System Issues (e.g., P0171/P0174):

    • Inspect fuel injectors for clogs and clean or replace as necessary.
    • Check the fuel filter and replace if clogged.
  • For Ignition System Issues (e.g., P0300):

    • Inspect spark plugs and ignition coils; replace worn or faulty components.
  • For Emission Control Issues (e.g., P0420):

    • Inspect the catalytic converter for damage or clogging; replace if necessary.
    • Check oxygen sensors and replace if faulty.

4. Reassemble and Reconnect

  • Reconnect any removed components, ensuring all connections are secure and tight.
  • Reconnect the battery's negative terminal.

5. Clear Error Codes

  • Using the OBD-II scanner, clear any stored error codes from the vehicle's ECU.

6. Test Drive

  • Take the vehicle for a test drive to ensure the check engine light does not re-illuminate and that performance has returned to normal.

Verification

After completing the repair, verify that the issue has been resolved:

  • Test the affected component to ensure it functions correctly
  • Check for any error codes or warning lights
  • Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • OBD-II scanner
  • Socket set
  • Torque wrench
  • Screwdrivers
  • Fuel pressure gauge

Parts Required

  • Replacement spark plugs
  • New ignition coils (if necessary)
  • Fuel filter
  • Oxygen sensors (if faulty)
  • Catalytic converter (if necessary)

Additional Information

Error CodeP0420
Component

Engine

Repair Time

2-4 hours

Difficulty

medium

Severity

medium

Tools

5 items

Parts

5 items

Related Faults

  1. how to replace the battery in my Ram 1500 DT (2019-Present) key fob

    Learn how to replace the battery in your Ram 1500 DT key fob. Step-by-step guide with symptoms, diagnostic steps, and tools required.

    Electrical5 symptoms
  2. how to troubleshoot a rough idle on Ram 1500 DT (2019-Present)

    Learn how to troubleshoot and fix rough idle issues on Dodge Ram 1500 DT (2019-Present). Step-by-step guide with diagnostic steps and solutions.

    Engine6 symptoms
  3. how to fix Ram 1500 DT (2019-Present) engine misfire P0302 code

    Learn how to diagnose and fix P0302 engine misfire in Ram 1500 DT. Step-by-step guide with diagnostic procedures and repair instructions.

    P0302Engine6 symptoms
  4. how to fix my Ram 1500 DT (2019-Present) if it is stalling at stop lights

    Learn how to diagnose and fix stalling issues in the 2019 Ram 1500 DT. Step-by-step guide with diagnostic procedures and repair instructions.

    Engine5 symptoms
  5. why does my Ram 1500 DT (2019-Present) fuel gauge not work

    Learn how to diagnose and fix the fuel gauge issue in your 2019 Ram 1500 DT. Step-by-step guide with diagnostic procedures and repair instructions.

    Fuel System5 symptoms
  6. my Ram 1500 is hard to start when cold what's the issue

    Learn how to diagnose and fix cold start issues in Ram 1500. Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

    Engine5 symptoms

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation