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Home/Cars/Ford/F-150/13th Generation (2015-2020)/how to fix Ford F-150 13th Generation (2015-2020) U0420 code

how to fix Ford F-150 13th Generation (2015-2020) U0420 code

Ford F-150 13th Generation (2015-2020)

Error Codes
Severity: highDifficulty: mediumError Code: U04202-4 hours
3 min read
513 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

Learn how to diagnose and fix U0420 code in Ford F-150 (2015-2020). Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
U0420
Affected Component
Electrical
Estimated Time
2-4 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems to avoid shorts or shocks.
  • ⚠Allow the vehicle's electronics to discharge fully before reconnecting the battery.

Symptoms

  • •Check engine light illuminated
  • •Inoperative or malfunctioning electrical accessories
  • •Erratic behavior of dashboard indicators
  • •Radio or entertainment system failure
  • •Difficulty starting the vehicle or intermittent starting issues

Diagnostic Steps

  1. 1Scan the vehicle's OBD-II system for error codes using an OBD-II scanner to confirm the U0420 code and check for any additional codes.
  2. 2Inspect the vehicle's wiring harness and connectors associated with the BCM for signs of damage, corrosion, or loose connections.
  3. 3Check the battery voltage to ensure it’s within the proper range (12.4V to 12.7V) and inspect battery terminals for corrosion.
  4. 4Verify that all related modules are receiving proper voltage and ground signals using a multimeter.
  5. 5Perform a visual inspection of the BCM for any signs of damage or water intrusion.
  6. 6If applicable, check for software updates from Ford that may address known issues with the BCM's programming.

Solution

Solution

1. Preparation

  • Tools Required: OBD-II scanner, multimeter, socket set, wiring diagram for the F-150.
  • Ensure the vehicle is parked on a level surface, and the engine is off.
  • Disconnect the negative battery cable to prevent any electrical shorts.

2. Inspect and Repair Wiring

  • Sub-steps:
    • Remove the vehicle's interior panels to access the BCM and associated wiring.
    • Visually inspect all wiring and connectors for frays, damage, or corrosion.
    • Repair or replace any damaged wiring or connectors using appropriate splices and heat shrink tubing.

3. Check and Update BCM Software

  • Sub-steps:
    • Reconnect the negative battery cable and start the vehicle.
    • Use the OBD-II scanner to check for BCM software updates.
    • If an update is available, follow the specific manufacturer instructions to update the BCM software.

4. Clear DTCs

  • Sub-steps:
    • After any repairs or updates, use the OBD-II scanner to clear the U0420 code and any other stored codes.
    • Perform a test drive to ensure that the error code does not return.

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
  • •Multimeter
  • •Socket set
  • •Wiring diagram for the F-150

Parts Required

  • •Replacement wiring or connectors (if damaged)
  • •Potentially a new BCM if the current module is defective

Additional Information

Error Code
U0420
Affected Component
Electrical
Estimated Time
2-4 hours
Difficulty
medium
Severity
high
Tools Required
4 items
Parts Required
2 items

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