P1452

DTC P1450 Fuel Tank Pressure Sensor
DTC P1451 Fuel Tank Pressure Sensor Range/Performance
DTC P1452 Fuel Tank Pressure Sensor Low Input
DTC P1453 Fuel Tank Pressure Sensor High Input

DTC Detection Condition:

DTC SUMMARY

DESCRIPTION





















NOTE: In this vehicle's EVAP system, turning ON the vent valve does not seal off the EVAP system. To check for leaks in the EVAP system, disconnect the air inlet vent hose and apply pressure from the atmosphere side of the canister.

While the engine is running, if a predetermined condition (closed loop, etc.) is met, the purge VSV is opened by the ECM and stored fuel vapors in the canister are purged to the intake manifold. The ECM changes the duty cycle ratio of the purge VSV to control purge flow volume.

The purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed into the canister through the vent valve to ensure that the purge flow is maintained when the negative pressure (vacuum) is applied to the canister.

Key-off monitor
This monitor checks for Evaporative Emission (EVAP) system leaks and canister pump module malfunctions. The monitor starts 5 hours* after the power switch is turned OFF. More than 5 hours are required to allow the fuel to cool down to stabilize the Fuel Tank Pressure (FTP), thus making the EVAP system monitor more accurate.

The leak detection pump creates negative pressure (vacuum) in the EVAP system and the pressure is measured. Finally, the ECM monitors for leaks from the EVAP system and malfunctions in both the canister pump module and purge VSV, based on the EVAP pressure.

HINT: *: If the engine coolant temperature is not below 35 °C (95 °F) 5 hours after the power switch is turned OFF, the monitor check starts 2 hours later. If it is still not below 35 °C (95 °F) 7 hours after the power switch is turned OFF, the monitor check starts 2.5 hours later.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions (Part 1):

Typical Enabling Conditions (Part 2):

Typical Malfunction Thresholds:

1. DTC P1451: Pressure sensor abnormal voltage fluctuation or being constant
If the pressure sensor output voltage fluctuates rapidly for 10 seconds, the ECM stops the EVAP system monitor. The ECM interprets this as the pressure sensor voltage fluctuating, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC.

Alternatively, if the sensor output voltage does not change for 10 seconds, the ECM interprets this as the sensor voltage being constant, and stops the monitor. The ECM then illuminates the MIL and sets the DTC.

(Both the malfunctions are detected by 2 trip detection logic).

2. DTC P1452: Pressure sensor voltage low
If the pressure sensor output voltage is below 0.45 V, the ECM interprets this as an open or short circuit malfunction in the pressure sensor or its circuit, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC (1 trip detection logic).

3. DTC P1453: Pressure sensor voltage high
If the pressure sensor voltage output is 4.9 V or more, the ECM interprets this as an open or short circuit malfunction in the pressure sensor or its circuit, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC (1 trip detection logic).

Wiring Diagram:

INSPECTION PROCEDURE

NOTE:
- When a vehicle is brought into the workshop, leave it as it is. Do not change the vehicle condition. For example, do not tighten the fuel tank cap.
- Do not disassemble the pump module.
- The intelligent tester is required to conduct the following diagnostic troubleshooting procedure.

Step 1-2:

Step 2(Continued)-3:

Step 4-7:

Step 8: