Toyota Corolla (E120): Monitor description

Dtc p0451, p0452 or p0453 is recorded by the ecm when the vapor pressure sensor malfunctions.

P0451

The ecm senses pressure in the fuel tank using the vapor pressure sensor. The ecm supplies the sensor with a regulated 5 v reference–voltage and the sensor returns a signal voltage between 0.5 V and 4.5 V according to the pressure level in the fuel tank.

When the pressure in the fuel tank is low, the output voltage of the vapor pressure sensor is low. When it is high, the output voltage is high.

For this dtc p0451, the ecm checks for a ”noisy” sensor or a ”stuck” sensor.

The ecm checks for the ”noisy” sensor by monitoring the fuel tank pressures when the vehicle is stationary and there should be little variation in the tank pressure. If the indicated pressure varies beyond specified limits, the ecm will illuminate the mil and a dtc is set.

The ecm checks for the ”stuck” sensor by monitoring the fuel tank pressure for an extended time period.

If the indicated pressure does not change over this period, the ecm will conclude that the fuel tank pressure sensor is malfunctioning. The ecm will illuminate the mil and a dtc is set.

P0452 and p0453

The ecm senses pressure in the fuel tank using the vapor pressure sensor. The ecm supplies the sensor with a regulated 5 v reference–voltage and the sensor returns a signal voltage between 0.5 V and 4.5 V according to the pressure level in the fuel tank.

When the pressure in the fuel tank is low, the output voltage of the vapor pressure sensor is low. When it is high, the output voltage is high.

If the output voltage of the vapor pressure sensor is out of the normal range, the ecm will determine that there is a malfunction in the sensor or sensor circuit.

When pressure indicated by the vapor pressure sensor deviates below –3.999 Kpa (–30 mmhg) or above 1.999 Kpa (15 mmhg), the ecm interprets this as a malfunction in the vapor pressure sensor. The ecm will turn on the mil and a dtc will be set.

Monitor strategy

Monitor strategy

P0451

P0452 and p0453

P0452 and p0453

Typical enabling conditions

Typical enabling conditions

P0451

P0452 and p0453

P0452 and p0453

Typical malfunction thresholds

Typical malfunction thresholds

P0451

P0452 and p0453

P0452 and p0453

Wiring diagram

Wiring diagram

Refer to dtc no. P0441

    Share this page:

    Other materials:

    Eco drive mode (if equipped)
    Press the switch. Suitable for enhancing the fuel economy, because the torque corresponding to the accelerator pedal depression amount can be generated more smoothly than it is in normal conditions and the operation of the air conditioning system (heating/cooling) will be minimized. Press th ...

    Circuit description
    The vehicle equipped with abs detects a vehicle speed using the stability control ecu and wheel speed sensor. This sensor monitors a wheel rotation speed and sends the signal to the ecu. The stability control ecu converts these wheel speed signals into a 4–pulse signal and outputs it to ...

    Engine assembly
    Inspection 1. Inspect coolant 2. Inspect engine oil 3. Inspect battery 4. Inspect air cleaner filter element sub–assy 5. Inspect spark plug 6. Inspect fan and generator v belt Hint: you don’t need to check the belt deflection because auto tensioner is adopted. 7. Inspect ignition ti ...