how to fix P0021 code in Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, oil catch pan.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down before working on the VVT components.

2. Inspect and Replace Engine Oil

• Sub-steps:
  1. Remove the engine oil drain plug using a socket wrench and drain the old oil into the catch pan.
  2. Replace the oil filter if necessary.
  3. Reinstall the drain plug and fill the engine with the recommended oil type (typically 0W-20 or 5W-20).
  4. Start the engine and check for leaks.

3. Test and Replace VVT Solenoid

• Sub-steps:
  1. Locate the VVT solenoid on the engine.
  2. Disconnect the electrical connector from the solenoid.
  3. Use a multimeter to measure the resistance of the solenoid; it should be within the manufacturer's specifications.
  4. If the solenoid is faulty, remove it using the socket set.
  5. Install the new VVT solenoid and reconnect the electrical connector.

4. Inspect and Align Timing Components

• Sub-steps:
  1. Remove the timing cover using a socket set.
  2. Rotate the engine to align the timing marks on the camshaft and crankshaft.
  3. If misaligned, adjust the timing by loosening the camshaft gear bolts and repositioning the camshaft.
  4. Re-torque the bolts to the manufacturer's specifications.
  5. Reinstall the timing cover.

5. Clear Codes and Test Drive

• Sub-steps:
  1. Reconnect the negative battery terminal.
  2. Use the OBD-II scanner to clear the P0021 code.
  3. Conduct a test drive to ensure the engine runs properly and the check engine light does not reappear.