P1453
1NZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1450: Fuel Tank Pressure Sensor
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 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
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).
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
P1450, P1452, P1453:
P1451:
TYPICAL MALFUNCTION THRESHOLDS
P1450:
P1451 (Noise Monitor):
P1451 (Stuck Monitor):
P1452:
P1453:
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
- 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.
- Techstream is required to conduct the following diagnostic troubleshooting procedure.
PROCEDURE
1. CONFIRM DTC AND FUEL TANK PRESSURE
(a) Connect Techstream to the DLC3.
(b) Turn the power switch ON (IG).
(c) Turn the tester on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
(e) Read DTCs.
(f) Enter the following menus: Powertrain / Engine and ECT / Data List / Vapor Press Tank.
(g) Read the EVAP (Evaporative Emission) pressure displayed on the tester.
Result:
C -- GO TO EVAP INSPECTION PROCEDURE
B -- CHECK HARNESS AND CONNECTOR (FUEL TANK PRESSURE SENSOR - ECM)
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (FUEL TANK PRESSURE SENSOR - ECM)
(a) Turn the power switch OFF.
(b) Disconnect the E7 ECM connector.
(c) Measure the resistance between the PTNK terminal of the ECM connector and the body ground.
Result:
(d) Reconnect the ECM connector.
B -- REPLACE ECM
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (FUEL TANK PRESSURE SENSOR - ECM)
(a) Remove the fuel tank assembly.
(b) Disconnect the V6 fuel tank pressure sensor connector.
(c) Disconnect the E7 ECM connector.
(d) Measure the resistance between the PTNK terminal of the ECM connector and the body ground.
Result:
(e) Reconnect the fuel tank pressure sensor connector.
(f) Reconnect the ECM connector.
(g) Reinstall the fuel tank assembly.
B -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- REPLACE FUEL TANK PRESSURE SENSOR
4. CHECK HARNESS AND CONNECTOR (FUEL TANK PRESSURE SENSOR - ECM)
(a) Remove the fuel tank assembly.
(b) Disconnect the V6 fuel tank pressure sensor connector.
(c) Turn the power switch ON (IG).
(d) Measure the voltage and resistance according to the value(s) in the table below.
Standard voltage:
Standard resistance:
Result:
(e) Reconnect the fuel tank pressure sensor connector.
(f) Reinstall the fuel tank assembly.
B -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- Continue to next step.
5. REPLACE FUEL TANK PRESSURE SENSOR
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
6. REPAIR OR REPLACE HARNESS OR CONNECTOR
HINT: If the exhaust tail pipe has been removed, go to the next step before reinstalling it.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
7. REPLACE ECM
(a) Replace the ECM Removal.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
8. CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
(a) Connect Techstream to the DLC3.
(b) Turn the power switch ON (IG) and turn the tester on.
(c) Wait for at least 60 seconds.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Code / Pending.
HINT: If no pending DTC is displayed on the tester, the repair has been successfully completed.
NEXT -- COMPLETED