how to fix P0171 code in Ram 1500 DT (2019-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, screwdriver.
• Sub-steps:
  1. Use a vacuum gauge to check for proper vacuum levels; a reading significantly lower than the manufacturer's specification indicates a leak.
  2. Visually inspect all vacuum hoses for signs of wear or damage.
  3. Replace any damaged hoses and ensure all connections are secure.

3. Clean or Replace Mass Airflow Sensor

• Tools Required: MAF sensor cleaner, screwdriver.
• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and remove the sensor.
  3. Clean the sensor using MAF sensor cleaner, ensuring no residue is left.
  4. Reinstall the sensor and reconnect the electrical connector.

4. Inspect and Repair Fuel Delivery System

• Tools Required: Fuel pressure gauge, wrench set.
• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail and turn the ignition to the "ON" position without starting the engine to check the fuel pressure.
  2. Compare the pressure reading with the manufacturer's specifications; replace the fuel pump if the pressure is low.
  3. Replace the fuel filter if it shows signs of clogging or has not been changed according to maintenance intervals.

5. Check for Intake System Leaks

• Tools Required: Torque wrench, gasket scraper.
• Sub-steps:
  1. Visually inspect the intake manifold and throttle body gaskets for signs of wear or damage.
  2. If leaks are found, remove the intake manifold/throttle body and replace the gaskets.
  3. Reinstall the manifold/throttle body and torque to the manufacturer's specifications.

6. Test Oxygen Sensors

• Tools Required: Multimeter, scan tool.
• Sub-steps:
  1. Use a multimeter to check the voltage of the upstream oxygen sensor while the engine is running.
  2. If the voltage is outside the normal range (typically 0.1 to 0.9 V), replace the oxygen sensor.
  3. Clear the P0171 code and perform a test drive to ensure the light does not reappear.