P1452
2AZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: P1451-P1453: Fuel Tank Pressure Sensor Range/Performance
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
While the engine is running, if a predetermined conditions (closed loop, etc.) are met, the purge VSV is opened by the ECM (included in the hybrid vehicle control ECU) and stored fuel vapors in the canister are purged to the intake manifold. The ECM will change the duty cycle ratio of the purge VSV to control purge flow volume.
Purge flow volume is also determined by the intake manifold pressure. Atmospheric pressure is allowed to enter into the canister through the vent valve to ensure that purge flow is maintained when negative pressure (vacuum) is applied to the canister.
The ECM monitors the condition of both the key-off monitor and purge flow monitor to ensure proper operation of the EVAP system.
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 (included in the hybrid vehicle control ECU) 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 (included in the hybrid vehicle control ECU) 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 (included in the hybrid vehicle control ECU) 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
P1451: (Noise Monitor)
Example of restart time:
P1451: (Stuck Monitor)
Example of restart time:
P1452 and P1453:
TYPICAL MALFUNCTION THRESHOLDS
1. P1451: Pressure sensor noise
2. P1451: Pressure sensor stuck
3. P1452: Pressure sensor low voltage
4. P1453: Pressure sensor high voltage
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.
- The Techstream is required to conduct the following diagnostic troubleshooting procedure.
PROCEDURE
1. CONFIRM DTC AND FUEL TANK PRESSURE
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG).
(c) Turn the tester on.
(d) Enter the following menus: Powertrain / Engine / Trouble Code.
(e) Read the DTCs.
(f) Enter the following menus: Powertrain / Engine / Data List / EVAP / Vapor Pressure Tank.
(g) Read the EVAP (Evaporative Emission) pressure displayed on the tester.
Result:
C -- GO TO EVAP INSPECTION PROCEDURE
B -- CHECK HARNESS OR CONNECTOR (VAPOR PRESSURE SENSOR - HYBRID VEHICLE CONTROL ECU)
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (FUEL TANK PRESSURE SENSOR - HYBRID VEHICLE CONTROL ECU)
(a) Turn the power switch off.
(b) Disconnect the A61 hybrid vehicle control ECU connector.
(c) Measure the resistance between the PTNK terminal of the hybrid vehicle control ECU connector and body ground.
Result:
(d) Reconnect the hybrid vehicle control ECU connector.
B -- REPLACE HYBRID VEHICLE CONTROL ECU
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (VAPOR PRESSURE SENSOR - HYBRID VEHICLE CONTROL ECU)
(a) Remove the fuel tank assembly.
(b) Disconnect the N35 vapor pressure sensor connector.
(c) Disconnect the A61 hybrid vehicle control ECU connector.
(d) Measure the resistance between the PTNK terminal of the hybrid vehicle control ECU connector and body ground.
Result:
(e) Reconnect the pressure sensor connector.
(f) Reconnect the hybrid vehicle control ECU connector.
(g) Install the fuel tank.
B -- REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- REPLACE FUEL TANK PRESSURE SENSOR
4. CHECK HARNESS OR CONNECTOR (VAPOR PRESSURE SENSOR - HYBRID VEHICLE CONTROL ECU)
(a) Remove the fuel tank assembly.
(b) Disconnect the N35 vapor 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:
Result:
(e) Reconnect the vapor pressure sensor connector.
(f) Install the fuel tank.
B -- REPAIR OR REPLACE HARNESS AND 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 AND 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 HYBRID VEHICLE CONTROL ECU
(a) Replace the hybrid vehicle control ECU Removal.
NEXT -- CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
8. CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)
(a) Connect the 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 / Trouble Code / Pending.
HINT: If no pending DTC is displayed on the tester, the repair has been successfully completed.
NEXT -- COMPLETED