how to fix P0174 code in Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, vacuum gauge, multimeter, cleaning solvent, rags.
• Disconnect the battery to prevent electrical shorts and ensure safety.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses for cracks or disconnections.
  2. Use a vacuum gauge to check for leaks by connecting it to a vacuum source.
  3. If leaks are found, replace damaged hoses or reconnect loose connections.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor between the air filter and the throttle body.
  2. Remove the electrical connector and unscrew the MAF sensor from the intake.
  3. Clean the sensor element using MAF cleaner spray; do not touch the sensor with fingers.
  4. If cleaning does not resolve the issue, replace the MAF sensor with a new one.

4. Check Fuel System

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect a fuel pressure gauge and turn the ignition on without starting the engine.
  3. Verify that the pressure is within the specifications (usually 40-50 psi for RAV4).
  4. If pressure is low, inspect the fuel pump, fuel filter, and fuel injectors for faults.

5. Inspect ECT Sensor

• Sub-steps:
  1. Locate the ECT sensor on the engine block.
  2. Disconnect the electrical connector and measure the resistance using a multimeter.
  3. Compare the resistance readings with the specifications for the sensor at various temperatures.
  4. Replace the ECT sensor if out of specification.