Toyota Avalon (XX50): Evaporative Emission System Leak Detected (Large Leak) (P045500,P045600). Fuel Level Sensor "A" Circuit Short to Battery (P046012,P046014). Vehicle Speed Sensor "A" No Signal (P050031)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Engine / 2gr-fks Engine Control / Sfi System / Evaporative Emission System Leak Detected (Large Leak) (P045500,P045600). Fuel Level Sensor "A" Circuit Short to Battery (P046012,P046014). Vehicle Speed Sensor "A" No Signal (P050031)

Evaporative Emission System Leak Detected (Large Leak) (P045500,P045600)

DTC SUMMARY

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P045500	Evaporative Emission System Leak Detected (Large Leak)	Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure is measured. Reference pressure is measured at start and end of leak check. If stabilized pressure is higher than [second reference pressure x 0.2], ECM determines that EVAP system has a large leak.	Fuel tank cap (loose) Leakage from EVAP line (canister - fuel tank) Leakage from EVAP line (purge VSV - canister) Leakage from canister pump module Leakage from fuel tank Leakage from canister	Comes on	DTC stored	SAE Code: P0455
P045600	Evaporative Emission System Leak Detected (Very Small Leak)	Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure is measured. Reference pressure measured at start and end of leak check. If stabilized pressure is higher than second reference pressure, ECM determines that EVAP system has a small leak.	Fuel tank cap (loose) Leakage from EVAP line (canister - fuel tank) Leakage from EVAP line (purge VSV - canister) Leakage from canister pump module Leakage from fuel tank Leakage from canister	Comes on	DTC stored	SAE Code: P0456

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P045500

Evaporative Emission System Leak Detected (Large Leak)

Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure is measured. Reference pressure is measured at start and end of leak check.

If stabilized pressure is higher than [second reference pressure x 0.2], ECM determines that EVAP system has a large leak.

Fuel tank cap (loose)
Leakage from EVAP line (canister - fuel tank)
Leakage from EVAP line (purge VSV - canister)
Leakage from canister pump module
Leakage from fuel tank
Leakage from canister

Comes on

DTC stored

SAE Code: P0455

P045600

Evaporative Emission System Leak Detected (Very Small Leak)

Leak detection pump creates negative pressure (vacuum) in EVAP system and EVAP system pressure is measured. Reference pressure measured at start and end of leak check.

If stabilized pressure is higher than second reference pressure, ECM determines that EVAP system has a small leak.

Fuel tank cap (loose)
Leakage from EVAP line (canister - fuel tank)
Leakage from EVAP line (purge VSV - canister)
Leakage from canister pump module
Leakage from fuel tank
Leakage from canister

Comes on

DTC stored

SAE Code: P0456

DTC No.	Monitoring Item	Detection Timing	Detection Logic	SAE
P045500	EVAP gross leak	EVAP monitoring (engine switch off)	2 trip	P0455
P045600	EVAP small leak	P0456

DTC No.

Monitoring Item

Detection Timing

Detection Logic

SAE

P045500

EVAP gross leak

EVAP monitoring

(engine switch off)

2 trip

P0455

P045600

EVAP small leak

P0456

DESCRIPTION

The description can be found in EVAP (Evaporative Emission) System.

Click here

MONITOR DESCRIPTION

5 hours* after the engine switch is turned off, the leak detection pump creates negative pressure (vacuum) in the EVAP (Evaporative Emission) system. The ECM monitors for leaks and actuator malfunctions based on the EVAP pressure.

HINT:

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

Sequence	Operation	Description	Duration
-	ECM activation	Activated by soak timer 5, 7 or 9.5 hours after engine switch turned off.	-
A	Atmospheric pressure measurement	Vent valve is turned off (vent) and EVAP system pressure is measured by ECM in order to register atmospheric pressure. If pressure in EVAP system is not between 70 to 110 kPa(abs) [10.15 to 15.95 psi(abs)], ECM cancels EVAP system monitor.	60 seconds
B	First reference pressure measurement	In order to determine reference pressure, leak detection pump creates negative pressure (vacuum) through reference orifice and then ECM checks if leak detection pump and vent valve operate normally.	360 seconds
C	EVAP system pressure measurement	Vent valve is turned on (closed) to shut EVAP system. Negative pressure (vacuum) is created in EVAP system, and EVAP system pressure is then measured. Write down measured value as it will be used in leak check. If EVAP pressure does not stabilize within 15 minutes, ECM cancels EVAP system monitor.	15 minutes*
D	Purge VSV monitor	Purge VSV is opened and then EVAP system pressure is measured by ECM. Large increase indicates normal.	10 seconds
E	Second reference pressure measurement	After second reference pressure measurement, leak check is performed by comparing first and second reference pressure measurements. If stabilized system pressure is higher than second reference pressure, ECM determines that EVAP system is leaking.	60 seconds
-	Final check	Atmospheric pressure is measured and then monitoring result is recorded by ECM.	-

*: If only a small amount of fuel is in the fuel tank, it takes longer for the EVAP pressure to stabilize.

*1	Purge VSV: Off (Closed)	*2	Purge VSV: On (Open)
*3	Vent Valve: Off (Vent)	*4	Vent Valve: On (Closed)
*5	Leak Detection Pump: Off	*6	Leak Detection Pump: On
*7	Reference Orifice (0.02 inch)	*8	Canister Pressure Sensor
*9	Canister	*10	Fuel Tank
*11	Canister Pump Module	*12	Canister Filter
*a	Operation A: Atmospheric Pressure Measurement	*b	Operation B, E: Reference Pressure Measurement
*c	Operation C: EVAP System Pressure Measurement	*d	Operation D: Purge VSV Monitor
*e	Atmospheric Pressure	*f	Negative Pressure

(a) P045500: EVAP (Evaporative Emission) gross leak
In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than [second reference pressure x 0.2] (near atmospheric pressure), the ECM determines that the EVAP system has a large leak, illuminates the MIL and stores this DTC (2 trip detection logic).
(b) P045600: EVAP very small leak
In operation C, the leak detection pump creates negative pressure (vacuum) in the EVAP system and the EVAP system pressure is measured. If the stabilized system pressure is higher than second reference pressure, the ECM determines that the EVAP system has a small leak, illuminates the MIL and stores this DTC (2 trip detection logic).

MONITOR STRATEGY

Required Sensors/Components (Main)	Purge VSV Canister pump module
Required Sensors/Components (Related)	-
Frequency of Operation	Once per driving cycle
Duration	Within 20 minutes (varies with amount of fuel in tank)
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Atmospheric pressure	70 kPa(abs) [10.15 psi(abs)] or higher, and less than 110 kPa(abs) [15.95 psi(abs)]
Battery voltage	10.5 V or higher
Vehicle speed	Less than 4 km/h (2.5 mph)
Engine switch	Off
Time after key-off	5, 7 or 9.5 hours
Canister pressure sensor malfunction (P0452, P0453)	Not detected
Purge VSV	Not operated by scan tool
Vent valve	Not operated by scan tool
Leak detection pump	Not operated by scan tool
Both of following conditions met before-key off	1 and 2
1. Duration that vehicle is driven	5 minutes or more
2. EVAP purge operation	Performed
Engine coolant temperature	4.4°C (40°F) or higher, and less than 35°C (95°F)
Intake air temperature	4.4°C (40°F) or higher, and less than 35°C (95°F)

TYPICAL MALFUNCTION THRESHOLDS

P0455: EVAP Gross Leak

EVAP pressure when vacuum introduction is complete

Higher than [reference pressure x 0.2]

P0456: EVAP Small Leak

EVAP pressure when vacuum introduction is complete

Between reference pressure and [reference pressure x 0.2]

MONITOR RESULT

Refer to EVAP system.

Click here

CONFIRMATION DRIVING PATTERN

NOTICE:

The Evaporative System Check (Automatic Mode) consists of 6 steps performed automatically by the Techstream. It takes a maximum of approximately 24 minutes.
Do not perform the Evaporative System Check when the fuel tank is higher than 85% full because the cut-off valve may be closed, making the fuel tank leak check unavailable.
Do not run the engine during this operation.
When the temperature of the fuel is 35°C (95°F) or higher, a large amount of vapor forms and any check results become inaccurate. When performing the Evaporative System Check, keep the fuel temperature less than 35°C (95°F).

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Click here
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) [A].
Turn the Techstream on.
Enter the following menus: Powertrain / Engine / Utility / Evaporative System Check / Automatic Mode [B].
After the Evaporative System Check is completed, check for All Readiness by entering the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P045500 or P045600.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions

HINT:

If the judgment result is NORMAL, the system is normal.
If the judgment result is ABNORMAL, the system is malfunctioning.
[A] to [B]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

PROCEDURE

1.	GO TO EVAP SYSTEM

(a) Refer to EVAP System.

Click here

END

Fuel Level Sensor "A" Circuit Short to Battery (P046012,P046014)

DESCRIPTION

The fuel sender gauge is located inside the fuel tank and measures the amount of fuel. The fuel sender gauge converts the fuel level in the fuel tank into a voltage value and outputs it to the combination meter assembly. The ECM determines when it is necessary to refuel the vehicle based on changes in the output value of the fuel sender gauge.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P046012	Fuel Level Sensor "A" Circuit Short to Battery	Fuel sender gauge output voltage is higher than 4.73 V for 30 seconds or more (2 trip detection logic).	Open or short in fuel sender gauge circuit Fuel sender gauge assembly Combination meter assembly ECM	Comes on	DTC stored	SAE Code: P0463
P046014	Fuel Level Sensor "A" Circuit Short to Ground or Open	Fuel sender gauge output voltage is less than 0.25 V for 30 seconds or more (2 trip detection logic).	Open or short in fuel sender gauge circuit Fuel sender gauge assembly Combination meter assembly ECM	Comes on	DTC stored	SAE Code: P0462

MONITOR DESCRIPTION

The combination meter assembly sends fuel level sensor signals to the ECM via CAN communication. When the engine switch is on (IG), if the output voltage of the fuel level sensor is less than 0.25 V or higher than 4.73 V for 30 seconds or more, the ECM will illuminate the MIL and store this DTC.

MONITOR STRATEGY

Related DTCs	P0462: Fuel level sensor range check (low voltage) P0463: Fuel level sensor range check (high voltage)
Required Sensors/Components (Main)	Fuel level sensor
Required Sensors/Components (Related)	-
Frequency of Operation	Continuous
Duration	30 seconds
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

All of the following conditions are met	-
Battery voltage	8 V or higher
Engine switch	On (IG)
Lost communication with instrument panel cluster control module (U0155)	Not detected

TYPICAL MALFUNCTION THRESHOLDS

P0462

Fuel level sensor voltage

Less than 0.25 V

P0463

Fuel level sensor voltage

Higher than 4.73 V

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Click here
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) [A].
Turn the Techstream on.
Wait 30 seconds or more [B].
Enter the following menus: Powertrain / Engine / Trouble Codes [C].
Read the pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P046012 or P046014.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
[A] to [C]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (FUEL SUCTION TUBE WITH PUMP AND GAUGE ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the fuel suction tube with pump and gauge assembly connector.

(b) Disconnect the combination meter assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
K38-1 (FV) - G16-15 (FV)	Always	Below 1 Ω
K38-3 (FS) - G16-14 (FR)	Always	Below 1 Ω
K38-2 (FE) - G16-33 (FE)	Always	Below 1 Ω
K38-1 (FV) or G16-15 (FV) - Body ground and other terminals	Always	10 kΩ or higher
K38-3 (FS) or G16-14 (FR) - Body ground and other terminals	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	INSPECT FUEL SENDER GAGE ASSEMBLY

(a) Remove the fuel sender gauge assembly.

Click here

(b) Inspect the fuel sender gauge assembly.

Click here

REPLACE FUEL SENDER GAGE ASSEMBLY

3.	INSPECT FUEL SUCTION TUBE WITH PUMP AND GAUGE ASSEMBLY

*a	Component without harness connected (Fuel Suction Tube with Pump and Gauge Assembly)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
K38-1 (FV) - A-3	Always	Below 1 Ω
K38-2 (FE) - A-2	Always	Below 1 Ω
K38-3 (FS) - A-1	Always	Below 1 Ω
K38-1 (FV) - K38-3 (FS) or A-3 - A-1	Always	10 kΩ or higher
K38-1 (FV) - K38-2 (FE) or A-3 - A-2	Always	10 kΩ or higher
K38-2 (FE) - K38-3 (FS) or A-2 - A-1	Always	10 kΩ or higher

REPLACE COMBINATION METER ASSEMBLY

REPLACE FUEL SUCTION TUBE WITH PUMP AND GAUGE ASSEMBLY

Vehicle Speed Sensor "A" No Signal (P050031)

DESCRIPTION

Vehicles, which are equipped with ABS (Anti-lock Brake System), detect the vehicle speed using the skid control ECU (brake actuator assembly) and speed sensor. The speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU. The skid control ECU converts the wheel speed signal into a 4-pulse signal and transmits it to the ECM via the combination meter assembly. The ECM determines the vehicle speed based on the frequency of the pulse signal.

HINT:

Various systems use the vehicle speed signal distributed from the combination meter assembly. Check all the components possibly related to the speed signal.
A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly.
The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls the respective system based on the pulse signal.
If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems using the speed signal will not operate normally.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P050031	Vehicle Speed Sensor "A" No Signal	While vehicle being driven, no vehicle speed sensor signal transmitted to ECM (2 trip detection logic).	Open or short in speed signal circuit Combination meter assembly ECM	Comes on	DTC stored	SAE Code: P0500

MONITOR DESCRIPTION

If there is no speed signal from the combination meter assembly even though the ECM determines that the vehicle is being driven, the ECM interprets this as a malfunction in the speed signal circuit. The ECM then illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Related DTCs	P0500: Vehicle speed sensor verify pulse input
Required Sensors/Components (Main)	Vehicle speed sensor Combination meter Skid control ECU
Required Sensors/Components (Related)	Park/neutral position switch Engine coolant temperature sensor Crankshaft position sensor Speed Sensor Throttle position sensor Mass air flow meter sub-assembly
Frequency of Operation	Continuous
Duration	5 seconds
MIL Operation	2 driving cycles
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

All of the following conditions are met	-
Battery voltage	8 V or higher
Engine switch	On (IG)
Starter	Off
Time after engine switch off to on (IG)	3 seconds or more
Engine	Running
Vehicle speed sensor monitor condition	Met
Lost communication with TCM (U0101)	Not detected

TYPICAL MALFUNCTION THRESHOLDS

Vehicle speed sensor signal

No signal

CONFIRMATION DRIVING PATTERN

HINT:

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Click here
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the engine switch off and wait for at least 30 seconds.
Turn the engine switch on (IG) [A].
Turn the Techstream on.
Start the engine [B].
Drive the vehicle at 24 km/h (15 mph) or more for a total of 30 seconds or more [C].
CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.
Stop the vehicle.
Enter the following menus: Powertrain / Engine / Trouble Codes [D].
Read the pending DTCs.
HINT:
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P050031.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions

HINT:

If the judgment result is NORMAL, the system is normal.
If the judgment result is ABNORMAL, the system has a malfunction.
If the judgment result is INCOMPLETE, perform steps [C] through [D] again.
[A] to [D]: Normal judgment procedure.
The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

PROCEDURE

1.	READ VALUE USING TECHSTREAM (VEHICLE SPEED)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(d) Enter the following menus: Powertrain / Engine / Data List / Vehicle Speed.

Powertrain > Engine > Data List

Tester Display
Vehicle Speed

(e) Drive the vehicle.

(f) Read the value displayed on the Techstream.

Result	Proceed to
Values displayed on Techstream and speedometer display not equal	A
Values displayed on Techstream and speedometer display equal	B

CHECK FOR INTERMITTENT PROBLEMS

2.	CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - ECM)

(a) Disconnect the combination meter assembly connector.

(b) Disconnect the ECM connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
G16-6 (+S) - A18-39 (SPD)	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	CHECK COMBINATION METER SYSTEM

(a) Check the circuits that send vehicle speed signals to this system in the combination meter system.

Click here

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(d) Clear the DTC.

Powertrain > Engine > Clear DTCs

(e) Turn the engine switch off and wait for at least 30 seconds.

5.	CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

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

Powertrain > Engine > Trouble Codes

HINT:

If no DTCs (no pending DTCs) are output to the Techstream, the repair has been successfully completed.

END

Evaporative Emission System Pressure Sensor/Switch Circuit Short to Ground (P045011,P045015,P04502A,P04502F)

Idle Control System (P050500)

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