how to fix U0101 code in Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect Wiring and Connectors

• Remove the plastic covers to access the wiring harness.
• Visually inspect the wiring for any frays, breaks, or corrosion.
• Clean and reseat any loose connectors between the ECM and TCM.
• Use contact cleaner if corrosion is present on the connectors.

3. Check Battery and Ground Connections

• Use a multimeter to measure battery voltage; it should read between 12.4V and 12.7V.
• Inspect the ground connections at the battery and chassis; ensure they are secure and free from corrosion.

4. Perform Continuity Test

• Set the multimeter to the continuity setting.
• Check the communication lines (CAN bus) between the ECM and TCM for continuity.
• If there is no continuity, trace the wiring for breaks and repair as necessary.

5. Replace Faulty Components

• If the wiring and connectors are intact but the code persists, consider replacing the ECM or TCM based on the continuity test results.
• Follow manufacturer-specific procedures for programming any new modules if replacements are made.