how to troubleshoot P0021 code in Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface with the engine off.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Check and Change Engine Oil

• Sub-steps:

  1. Remove the engine oil dipstick and check the oil level; add oil if low.
  2. If oil is dirty or has not been changed recently, drain the old oil using a wrench and replace it with new oil (consult the owner’s manual for specifications).
  3. Replace the oil filter if necessary.

• Tools Required: Wrench, oil filter wrench, oil catch pan.

3. Inspect and Replace VVT Solenoid

• Sub-steps:

  1. Locate the VVT solenoid on the engine. It is typically near the camshaft cover.
  2. Disconnect the electrical connector and remove the mounting bolts.
  3. Replace the solenoid with a new one and reattach the electrical connector.

• Tools Required: Socket set.

4. Inspect Timing Chain/Belt

• Sub-steps:

  1. Remove the timing cover to access the timing chain/belt.
  2. Check for any signs of wear, damage, or misalignment.
  3. If the timing is off, realign or replace the timing chain/belt as necessary.

• Tools Required: Socket set, torque wrench.

5. Test VVT Actuator

• Sub-steps:

  1. Reconnect the negative battery terminal.
  2. Start the engine and use a multimeter to check the VVT actuator's voltage and operation.
  3. If it fails to operate as specified, replace the actuator.

• Tools Required: Multimeter.