Last Modified: 4-30-2014 6.6 C Doc ID: RM000000YE6006X
Model Year: 2006 Model: LX470 Prod Date Range: [05/2005 - 01/2006]
Title: 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0450-P0453; Evaporative Emission Control System Pressure Sensor Malfunction; 2006 MY LX470 [05/2005 - 01/2006]

DTC

P0450

Evaporative Emission Control System Pressure Sensor Malfunction

DTC

P0451

Evaporative Emission Control System Pressure Sensor Range / Performance

DTC

P0452

Evaporative Emission Control System Pressure Sensor / Switch Low Input

DTC

P0453

Evaporative Emission Control System Pressure Sensor / Switch High Input

DTC SUMMARY

DTC No.

Monitoring Items

Malfunction Detection Conditions

Trouble Area

Detection Timing

Detection logic

P0450

Canister pressure sensor voltage abnormal fluctuation

Sensor output voltage rapidly fluctuates beyond upper and lower malfunction thresholds for 0.5 seconds.
  • Canister pump module
  • ECM
  • EVAP monitoring (ignition switch OFF)
  • Ignition switch ON

1 trip

P0451

Canister pressure sensor noisy

Sensor output voltage fluctuates frequently in certain time period.
  • Canister pump module
  • Connector/wire harness (canister pump module - ECM)
  • ECM
  • EVAP monitoring (ignition switch OFF)
  • Engine running

2 trip

P0451

Canister pressure sensor stuck

Sensor output voltage does not vary in certain time period.
  • Canister pump module
  • Connector/wire harness (canister pump module - ECM)
  • ECM
  • EVAP monitoring (ignition switch OFF)

2 trip

P0452

Canister pressure sensor voltage low

Sensor output voltage less than 0.45 V for 0.5 seconds.
  • Canister pump module
  • Connector/wire harness (canister pump module - ECM)
  • ECM
  • EVAP monitoring (ignition switch OFF)
  • Ignition switch ON

1 trip

P0453

Canister pressure sensor voltage high

Sensor output voltage more than 4.9 V for 0.5 seconds.
  • Canister pump module
  • Connector/wire harness (canister pump module - ECM)
  • ECM
  • EVAP monitoring (ignition switch OFF)
  • Ignition switch ON

1 trip

HINT:

The Canister pressure sensor is built into the canister pump module.

DESCRIPTION

The circuit description can be found in the Evaporative Emission (EVAP) system 2006 MY LX470 [05/2005 - 01/2006]; 2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: EVAP System .

MONITOR DESCRIPTION

    1. DTC P0450: Canister pressure sensor voltage abnormal fluctuation

      If the canister pressure sensor voltage output rapidly fluctuates between less than 0.45 V and more than 4.9 V, the ECM interprets this as an open or short circuit malfunction in the canister 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).

    2. DTC P0451: Canister pressure sensor noisy or stuck

      If the canister pressure sensor voltage output fluctuates rapidly for 10 seconds, the ECM stops the EVAP system monitor. The ECM interprets this as noise from the canister pressure sensor, and stops the EVAP system monitor. The ECM then illuminates the MIL and sets the DTC.

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

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

    3. DTC P0452: Canister pressure sensor voltage low

      If the canister pressure sensor voltage output is below 0.45 V, the ECM interprets this as an open or short circuit malfunction in the canister 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).

    4. DTC P0453: Canister pressure sensor voltage high

      If the canister pressure sensor voltage output is 4.9 V or more, the ECM interprets this as an open or short circuit malfunction in the canister 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

Required Sensors/Components

Canister pump module

Frequency of Operation

Once per driving cycle: P0451 sensor stuck

Continuous: P0451 sensor noisy, P0450, P0452 and P0453

Duration

Within 120 seconds

MIL Operation

Immediate: P0450, P0452, P0453

2 driving cycles: P0451

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

P0451 (Noise Monitor):

Monitor runs whenever following DTCs are not present

None

Atmospheric pressure

70 to 110 kPa (525 to 825 mmHg)

[absolute pressure]

Battery voltage

10.5 V or more

Intake air temperature

4.4 to 35 °C (40 to 95°F)

EVAP canister pressure sensor malfunction (P0450, P0452, P0453)

Not detected

Either of following conditions is met

A or B

A. Engine

Running

B. Soak time (ignition switch OFF time)

5 hours

Example of restart time

First time

7 hours

Second time

9 hours and 30 minutes

P0451 (Stuck Monitor):

Monitor runs whenever following DTCs are not present

None

Atmospheric pressure

70 to 110 kPa (525 to 825 mmHg)

Battery voltage

10.5 V or more

Intake air temperature

4.4 to 35°C (40 to 95°F)

Soak time (ignition switch OFF time)

5 hours

Example of restart time

First time

7 hours

Second time

9 hours and 30 minutes

P0450, P0452 and P0453:

Monitor runs whenever following DTCs are not present

None

Either of following conditions is met

A or B

A. Ignition switch

ON

B. Soak time

ON

TYPICAL MALFUNCTION THRESHOLDS

  1. P0450: Canister pressure sensor chattering

    EVAP pressure

    Less than 42.1 kPa (317 mmHg) or more than 123.8 kPa (928.5 mmHg)
  2. P0451: Canister pressure sensor noise

    Pressure variation indicated by canister pressure sensor in 10 seconds

    More than +-0.3 kPa (+-2.25 mmHg) 10 times
  3. P0451: Canister pressure sensor stuck

    0.02 inch leak criterion variation indicated by canister pressure sensor in 10 seconds

    Less than 0.65 kPa (4.87 mmHg)
  4. P0452: Canister pressure sensor low voltage

    EVAP pressure

    Less than 42.1 kPa (317 mmHg)
  5. P0453: Canister pressure sensor high voltage

    EVAP pressure

    More than 123.8 kPa (928.5 mmHg)

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 cap.
  • Do not disassemble the canister pump module.
  • The intelligent tester is required to conduct the following diagnostic troubleshooting procedure.

PROCEDURE

1.

CONFIRM DTC AND EVAP PRESSURE

(a) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.

(b) Turn the ignition switch ON and turn the intelligent tester ON.

(c) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

(d) Read the values.

(e) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / EVAP / VAPOR PRESS.

(f) Read the EVAP pressure displayed on the intelligent tester.

Display (DTC Output)

Test Result

Suspected Trouble Areas

Proceed to

P0451

-
  • Canister pressure sensor

A

P0452

Less than 45 kPa (430 mmHg)
  • Wire harness/connector (ECM - canister pressure sensor)
  • Canister pressure sensor
  • Short in ECM circuit

B

P0453

More than 120 kPa (900 mmHg)
  • Wire harness/connector (ECM - canister pressure sensor)
  • Canister pressure sensor
  • Open in ECM circuit

C
A

GO TO EVAP SYSTEM

C

GO TO STEP 4

B

2.

CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)

(a) Disconnect the E10 ECM connector.

(b) Turn the ignition switch OFF.

(c) Measure the resistance of the wire harness side connectors.

Test Results

Suspected Trouble Areas

Proceed to

10 Ω or less
  • Wire harness/connector (ECM - canister pressure sensor)
  • Short in canister pressure sensor circuit

A

10 kΩ or more
  • Wire harness/connector (ECM - canister pressure sensor)
  • Short in ECM circuit

B
B

GO TO STEP 7

A

3.

CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)

(a) Disconnect the L4 canister connector.

(b) Disconnect the E10 ECM connector.

(c) Measure the resistance of the wire harness side connectors.

Test Results

Suspected Trouble Areas

Proceed to

10 kΩ or more
  • Short in canister pressure sensor circuit

A

10 kΩ or less
  • Short in wire harness/connector (ECM - canister pressure sensor)

B
B

GO TO STEP 6

A

4.

CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)

(a) Disconnect the L4 canister connector.

(b) Turn the ignition switch ON.

(c) Measure the voltage of the canister pump module connector.

Standard voltage:

Tester Connections

Specified Conditions

L4-4 - Body ground

4.5 to 5.0 V

L4-3 - Body ground

4.5 to 5.0 V

L4-2 - Body ground

100 Ω or less

Test Results

Suspected Trouble Areas

Proceed to

Voltage and resistance within standard ranges
  • Open in canister pressure sensor circuit

A

Voltage and resistance outside standard ranges
  • Open in wire harness/connector (ECM - canister pressure sensor)

B
B

GO TO STEP 6

A

5.

REPLACE CANISTER ASSEMBLY

(a) Replace canister assembly 2006 MY LX470 [05/2005 -        ]; 2UZ-FE EMISSION CONTROL: CANISTER: REMOVAL .

NEXT

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

7.

REPLACE ECM

(a) Replace ECM 2006 MY LX470 [05/2005 -        ]; 2UZ-FE ENGINE CONTROL SYSTEM: ECM: REMOVAL .

NEXT

8.

CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)

(a) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.

(b) Turn the ignition switch ON and turn the intelligent tester ON.

(c) Wait for at least 60 seconds.

(d) Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / PENDING CODES.

HINT:

If no pending DTC is displayed on the intelligent tester, the repair has been successfully completed.

NEXT

COMPLETED