Last Modified: 11-29-2007 1.6 C
Service Category: Engine/Hybrid System Section: Engine Control
Model Year: 2008 Model: Sequoia Doc ID: RM0000012MC01DX
Title: 2UZ-FE ENGINE CONTROL: SFI SYSTEM: DTC SUMMARY (2008 Sequoia)

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 Item

DTC Detection Condition

Trouble Area

Detection Timing

Detection Logic

P0451

Canister pressure sensor noise

Sensor output voltage fluctuates frequently within certain time period.
  • Canister pump module
  • Connector/wire harness

    (Canister pump module - ECM)

  • EVAP system hose (pipe from air inlet port to canister pump module, canister filter, fuel tank vent hose)
  • ECM
  • EVAP monitoring (ignition switch off)
  • Engine running

2 trip

Canister pressure sensor signal becomes fixed/flat

Sensor output voltage does not vary within certain time period.
  • Canister pump module
  • Connector/wire harness

    (Canister pump module - ECM)

  • EVAP system hose (pipe from air inlet port to canister pump module, canister filter, fuel tank vent hose)
  • ECM
  • EVAP monitoring (ignition switch off)

2 trip

P0452

Canister pressure sensor low input

EVAP pressure less than 42.1 kPa for 0.5 seconds.
  • Canister pump module
  • Connector/wire harness

    (Canister pump module - ECM)

  • EVAP system hose (pipe from air inlet port to canister pump module, canister filter, fuel tank vent hose)
  • ECM
  • Ignition switch ON
  • EVAP monitoring (ignition switch off)

1 trip

P0453

Canister pressure sensor high input

EVAP pressure more than 123.8 kPa for 0.5 seconds.
  • Canister pump module
  • Connector/wire harness

    (Canister pump module - ECM)

  • EVAP system hose (pipe from air inlet port to canister pump module, canister filter, fuel tank vent hose)
  • ECM
  • Ignition switch ON
  • EVAP monitoring (ignition switch off)

1 trip

HINT:

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

DESCRIPTION

The description can be found in the EVAP (Evaporative Emission) System 2UZ-FE ENGINE CONTROL: SFI SYSTEM: RELATED DTCS (2008 Sequoia)+ .

MONITOR DESCRIPTION



  • DTC P0451: Canister pressure sensor noise or fixed/flat

    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 stores the DTC.

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

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

  • DTC P0452: Canister pressure sensor voltage low

    If the canister pressure sensor output [pressure] is below 42.1 kPa-a (315.9 mmHg-a), 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 stores the DTC (1 trip detection logic).

  • DTC P0453: Canister pressure sensor voltage high

    If the canister pressure sensor output [pressure] is 123.8 kPa-a (928.4 mmHg-a) 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 stores the DTC (1 trip detection logic).

MONITOR STRATEGY

Required Sensors/Components

Canister pump module

Frequency of Operation

Once per driving cycle: P0451 sensor fixed/flat

Continuous: P0451 sensor noise, P0452 and P0453

Duration

0.5 seconds: P0452 and P0453

2 minutes: P0451

MIL Operation

Immediate: P0452 and P0453

2 driving cycles: P0451

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

P0451 (Noise Monitor)

Monitor runs whenever following DTCs not present

None

Atmospheric pressure (absolute pressure)

70 to 110 kPa-a (525 to 825 mmHg-a)

Battery voltage

10.5 V or more

Intake air temperature

4.4 to 40°C (40 to 104°F)

Canister pressure sensor malfunction (P0452, 0453)

Not detected

Either of following conditions met

A or B

A. Engine condition

Running

B. Time after key off

5 or 7 or 9.5 hours

P0451 (Fixed/Flat Monitor)

Monitor runs whenever following DTCs not present

None

Battery voltage

10.5 V or more

Intake air temperature

4.4 to 40°C (40 to 104°F)

Canister pressure sensor malfunction (P0452, 0453)

Not detected

Atmospheric pressure (absolute pressure)

Less than 70 kPa-a (525 mmHg-a) or 110 kPa-a (825 mmHg-a) or more

Time after key off

5 or 7 or 9.5 hours

P0452 and P0453

Monitor runs whenever following DTCs not present

None

Either of following conditions met

(a) or (b)

(a) Ignition switch

ON

(b) Soak timer

ON

TYPICAL MALFUNCTION THRESHOLDS

P0451: Canister Pressure Sensor Noise

Frequency that EVAP pressure change 0.3 kPa-g (2.25 mmHg-g) or more

10 times or more in 10 seconds

P0451: Canister Pressure Sensor Fixed/Flat

EVAP pressure change during reference pressure

Less than 0.65 kPa-g (4.87 mmHg-g)

P0452: Canister Pressure Sensor Low Voltage

EVAP pressure

Less than 42.1 kPa-a (315.9 mmHg-a)

P0453: Canister Pressure Sensor High Voltage

EVAP pressure

More than 123.8 kPa-a (928.4 mmHg-a)

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 Techstream is required to conduct the following diagnostic troubleshooting procedure.

PROCEDURE

1.

CONFIRM DTC AND EVAP PRESSURE

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON (do not start the engine).

(c) Turn the Techstream ON.

(d) Enter the following menus: Powertrain / Engine / Trouble Codes.

(e) Read DTCs.

(f) Enter the following menus: Powertrain / Engine / Data List / EVAP / Vapor Pressure Pump.

(g) Read the EVAP (Evaporative Emission) pressure displayed on the Techstream.

Result

DTC No.

Result

Suspected Trouble Area

Proceed to

P0451

-

Canister pressure sensor

C

P0452

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

A

P0453

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

B
A

2.

CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)


(a) Turn the ignition switch off.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Result

Tester Connection

Result

Suspected Trouble Area

Proceed to

D56-121 (PPMP) - Body ground

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

A

D56-121 (PPMP) - Body ground

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

B
A

3.

CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)


(a) Disconnect the canister pump module connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Result

Tester Connection

Result

Suspected Trouble Area

Proceed to

D56-121 (PPMP) - Body ground

10 kΩ or more

Short in canister pressure sensor circuit

A

D56-121 (PPMP) - Body ground

10 Ω or less

Short in wire harness/connector (ECM - Canister pressure sensor)

B

5.

CHECK HARNESS AND CONNECTOR (CANISTER PUMP MODULE - ECM)


(a) Disconnect the canister pump module connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

O24-2 (SGND) - Body ground

Always

100 Ω or less

(c) Turn the ignition switch to ON.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

O24-4 (VCC) - Body ground

Ignition switch ON

4.5 to 5.5 V

O24-3 (VOUT) - Body ground

Ignition switch ON

4.5 to 5.5 V

Result

Result

Suspected Trouble Area

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
A

6.

REPLACE CHARCOAL CANISTER ASSEMBLY

(a) Replace the canister assembly 2UZ-FE EMISSION CONTROL: CANISTER: REMOVAL (2008 Sequoia) .

NOTICE:

When replacing the canister, check the canister pump module interior and related pipes for water, fuel and other liquids. If liquids are present, check for disconnections and/or cracks in the following: 1) the pipe from the air inlet port to the canister pump module; 2) the canister filter; and 3) the fuel tank vent hose.



7.

REPAIR OR REPLACE HARNESS OR CONNECTOR (CANISTER PUMP MODULE - ECM)

HINT:

If the exhaust tailpipe has been removed, go to the next step before reinstalling it.

8.

REPLACE ECM

(a) Replace the ECM 2UZ-FE ENGINE CONTROL: ECM: REMOVAL (2008 Sequoia) .

NEXT

9.

CHECK WHETHER DTC OUTPUT RECURS (AFTER REPAIR)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream ON.

(d) Wait for at least 60 seconds.

(e) Enter the following menus: Powertrain / Engine / Trouble Codes / Pending.

HINT:

If no pending DTCs are displayed on the Techstream, the repair has been successfully completed.

NEXT