my Toyota Corolla E140 (2006-2013) won’t start in cold weather what could it be

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, fuel pressure gauge, basic hand tools (sockets, wrenches), and safety gloves.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.

2. Battery Inspection and Replacement

• Inspect Battery Condition

  • Disconnect the negative terminal first, followed by the positive terminal.
  • Clean any corrosion from battery terminals using a wire brush.
  • Reconnect terminals and ensure they are tight.

• Test Battery Voltage

  • If the voltage is below 12.4 volts, consider charging the battery or replacing it if it fails to hold a charge.

3. Fuel System Check

• Check Fuel Pressure
  • Locate the fuel pressure test port on the fuel rail.
  • Attach the fuel pressure gauge and turn the ignition to the 'ON' position (do not start).
  • Observe the fuel pressure reading; it should be within the manufacturer’s specified range (typically around 40-50 psi for most Corollas). If low, check the fuel pump and filter.

4. Ignition System Check

• Inspect Spark Plugs and Coils
  • Remove the spark plug wires or coils to access the spark plugs.
  • Inspect spark plugs for wear and carbon buildup; replace if necessary.
  • Test ignition coils with a multimeter; replace any that are out of specification.

5. Replace Engine Coolant Temperature Sensor (if faulty)

• Remove and Replace Sensor
  • Locate the engine coolant temperature sensor (usually near the thermostat housing).
  • Disconnect the electrical connector and remove the sensor using the appropriate socket.
  • Install the new sensor, ensuring a proper seal with Teflon tape if required.
  • Reconnect the electrical connector.