how to fix U0101 code in Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to avoid electrical shorts.
• Ensure the vehicle is on a level surface and secured with wheel chocks.

2. Inspect and Repair Wiring

• Sub-step 1: Visually inspect the wiring harness connecting the ECM and TCM.
• Sub-step 2: Look for frayed wires, corrosion, or loose connectors.
• Sub-step 3: Repair or replace any damaged wiring or connectors as needed.
• Tools Required: Wire strippers, soldering iron, heat shrink tubing.

3. Check and Replace Fuses

• Sub-step 1: Locate the fuse box and identify the fuses related to the ECM and TCM.
• Sub-step 2: Inspect each fuse for continuity with a multimeter.
• Sub-step 3: Replace any blown fuses with the same amperage rating.
• Tools Required: Fuse puller or pliers.

4. Test and Replace TCM (if necessary)

• Sub-step 1: Reconnect the battery and perform a communication test with the OBD-II scanner.
• Sub-step 2: If communication is still faulty, remove the TCM from the vehicle.
• Sub-step 3: Install a new or refurbished TCM and ensure all connections are secure.
• Tools Required: Socket set, torque wrench.

5. Reprogram TCM and ECM (if necessary)

• Sub-step 1: If a new TCM was installed, follow the manufacturer's procedure for programming the new unit.
• Sub-step 2: Use a compatible diagnostic tool to ensure the ECM and TCM are communicating properly after reprogramming.