how to fix P0174 code in Toyota Corolla E170 (2013-2019)

Learn how to diagnose and fix P0174 fuel system issue in Toyota Corolla E170 (2013-2019). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal.
• Ensure the engine is cool before starting.

2. Inspect and Replace Vacuum Hoses

• Sub-steps:
  • Visually inspect all vacuum hoses for cracks, breaks, or disconnections.
  • Replace any damaged hoses with OEM or high-quality aftermarket parts.
• Tools Required: Pliers, hose cutter
• Safety Warnings: Ensure the vehicle is off and cool before inspection.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Locate the MAF sensor in the intake duct.
  • Disconnect the electrical connector and remove the sensor.
  • Clean the MAF sensor using MAF sensor cleaner; allow it to dry completely before reinstallation.
  • If cleaning does not resolve the issue, replace the MAF sensor with a new one.
• Tools Required: Screwdriver, MAF sensor cleaner
• Safety Warnings: Avoid touching the sensor element with fingers.

4. Test and Replace Fuel Injectors (if necessary)

• Sub-steps:
  • Perform a resistance test on each fuel injector using a multimeter; compare readings to factory specifications.
  • If any injector is out of specification, replace the faulty injector.
• Tools Required: Multimeter, socket set
• Safety Warnings: Allow the fuel system to depressurize before servicing injectors.

5. Check Fuel Pressure

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail's test port.
  • Turn the ignition to the "ON" position (do not start) and check the pressure reading against the manufacturer's specifications.
  • If pressure is low, inspect the fuel pump and fuel filter for issues.
• Tools Required: Fuel pressure gauge
• Safety Warnings: Fuel can be flammable; handle all components carefully.