FAULTBASE
Error CodesASKCars
© 2025 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
Home/Cars/Toyota/Corolla/E170 (2013-2019)/how to clear the U0100 code on my Toyota Corolla E170 (2013-2019)

how to clear the U0100 code on my Toyota Corolla E170 (2013-2019)

Toyota Corolla E170 (2013-2019)

Error Codes
Severity: highDifficulty: mediumError Code: U01001-3 hours
3 min read
474 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 U0100 communication issues in Toyota Corolla E170 (2013-2019). Step-by-step guide with diagnostic procedures and repair instructions.

Error Code
U0100
Affected Component
Electrical
Estimated Time
1-3 hours

Safety Warnings

  • ⚠Disconnect the battery before working on electrical systems to prevent shorts or shocks.

Symptoms

  • •Check engine light illuminated
  • •Erratic shifting or transmission issues
  • •Reduced engine performance
  • •Difficulty starting the vehicle
  • •Potential loss of cruise control functionality

Diagnostic Steps

  1. 1Scan the vehicle using an OBD-II scanner to confirm the U0100 code and check for additional codes.
  2. 2Inspect all related wiring and connectors between the ECM and TCM for damage, corrosion, or loose connections.
  3. 3Check the vehicle’s battery voltage and ground connections to ensure they are functioning properly.
  4. 4Test the ECM and TCM for proper operation using a scan tool capable of reading live data.
  5. 5Clear the trouble codes using the OBD-II scanner and perform a test drive to see if the code reappears.

Solution

Solution

1. Preparation

  • Gather tools: OBD-II scanner, multimeter, socket set, and screwdrivers.
  • Disconnect the negative battery terminal to prevent electrical shorts.
  • Ensure the vehicle is parked on a level surface and the engine is off.

2. Inspect Wiring and Connectors

  • Remove any protective covers to access the wiring harness between the ECM and TCM.
  • Visually inspect the wiring for frays, cuts, or signs of wear.
  • Use a multimeter to check for continuity in the wiring between the ECM and TCM connectors.
    • Note: If any wiring is damaged, repair it by soldering or replacing the affected section.

3. Check Module Functionality

  • Reconnect the negative battery terminal.
  • Use the OBD-II scanner to perform a functional test of the ECM and TCM.
    • If either module is unresponsive, consider replacing it based on manufacturer specifications.

4. Clear the Code

  • Use the OBD-II scanner to clear the U0100 code from the system.
  • After clearing, perform a test drive to ensure that the issue does not reoccur.

5. Final Checks

  • If the code reappears, further diagnostics of the ECM or TCM may be necessary, including replacement if found faulty.

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
  • •Screwdrivers

Parts Required

  • •Replacement wiring harness (if damaged)
  • •ECM or TCM (if faulty)

Additional Information

Error Code
U0100
Affected Component
Electrical
Estimated Time
1-3 hours
Difficulty
medium
Severity
high
Tools Required
4 items
Parts Required
2 items

Related Faults

  1. Radiator failure Toyota Corolla

    Learn how to diagnose and repair radiator failure in a Toyota Corolla E170 (2013-2019). Symptoms include engine overheating and coolant leaks. Follow our step-by-step guide.

    radiator5 symptoms

  2. why is my Toyota Corolla E170 (2013-2019) steering wheel so hard to turn?

    Discover the causes and solutions for a hard-to-turn steering wheel in the 2013-2019 Toyota Corolla E170. Step-by-step diagnostic and repair guide.

    Steering5 symptoms

  3. Rough idle Toyota Corolla E170

    Learn how to diagnose and fix rough idle issues in Toyota Corolla E170 (2013-2019). Follow our comprehensive guide with symptoms, diagnostic steps, and repair instructions.

    engine4 symptoms

  4. Diagnose fuse keeps blowing Toyota Corolla

    Learn how to diagnose and repair a fuse that keeps blowing in your Toyota Corolla E170. Follow detailed steps to identify and resolve electrical issues.

    electrical system3 symptoms

  5. Engine knocking solution Corolla

    Learn how to diagnose and resolve engine knocking in a Toyota Corolla E170 with this comprehensive guide. Includes symptoms, diagnostic steps, and repair instructions.

    engine5 symptoms

  6. how to fix P0420 code on Toyota Corolla E170 (2013-2019)

    Learn how to diagnose and fix P0420 catalytic converter issues in Toyota Corolla E170 (2013-2019). Step-by-step guide with diagnostic procedures and repair instructions.

    P0420Exhaust System5 symptoms

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation