how to fix U0100 code on Honda Accord 9th Generation (2013-2017)

Learn how to diagnose and fix U0100 code related to electrical communication issues in Honda Accord 9th Generation. Step-by-step guide included.

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Inspect Wiring and Connectors

• Tools Required: Pliers, Electrical cleaner
• Inspect the wiring harness connected to the ECM.
  • Look for frayed wires, corrosion, or bent pins.
  • Clean connectors with electrical cleaner.
• If any damaged wires are found, repair or replace them as necessary.

3. Check and Replace Fuses

• Tools Required: Fuse puller or pliers
• Locate the fuse box and identify fuses related to the ECM.
  • Remove and inspect each fuse.
  • Replace any blown fuses with the correct amperage rating.

4. Test Power and Ground at the ECM

• Tools Required: Multimeter
• Reconnect the battery and turn the ignition to the "ON" position (do not start the engine).
• Measure the voltage at the ECM power terminals.
  • Ensure it reads around 12V.
  • If there is no voltage, trace the wiring back to the fuse box and battery.
• Check the ground connection to the ECM.
  • Ensure continuity to the chassis ground.

5. Reconnect and Test ECM

• If wiring and power checks are clear, reconnect the ECM connectors.
• Tools Required: OBD-II scanner
• Clear the U0100 code from the system using the OBD-II scanner.
• Start the engine and monitor for any reoccurring codes.