Toyota Corolla Cross: Fuel Pump Control Circuit

DESCRIPTION

The fuel pump (for low pressure side) circuit consists of the ECM, fuel pump (for low pressure side) and fuel pump control ECU (which operates the fuel pump (for low pressure side)). Based on the engine output, the ECM determines the fuel pump speed. The speed is then converted to a duty signal and sent to the fuel pump control ECU. Based on the signal sent from the ECM, the fuel pump control ECU adjusts the fuel pump (for low pressure side) operation speed.

WIRING DIAGRAM

Refer to DTC P062712.

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CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	CHECK FUEL LEAK

(a) Check around and beneath the vehicle for fuel leaks, fumes, etc.

OK:

No fuel leaks present.

NG

REPAIR OR REPLACE FUEL LEAK POINT

OK

2.	PERFORM ACTIVE TEST USING GTS (ACTIVATE THE CIRCUIT RELAY (BRUSHLESS))

(a) Enter the following menus.

Powertrain > Engine > Active Test

Tester Display
Activate the Circuit Relay (Brushless)

(b) Check whether the fuel pump operating sound occurs when performing the Active Test on the GTS.

Standard:

GTS Operation	Standard
ON	Operating sounds can be heard from fuel pump (for low pressure side)

NG

GO TO STEP 8

OK

3.	PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP DUTY RATIO (BRUSHLESS))

(a) Install the fuel pressure gauge (for low pressure line of low pressure side).

Click here

(b) Enter the following menus.

Powertrain > Engine > Active Test

Active Test Display
Control the Fuel Pump Duty Ratio (Brushless)

Data List Display
Fuel Pressure (Low) / Fuel Pressure 2

(c) Compare the values in the Data List using the GTS and the fuel pressure gauge when the Active Test was performed.

Standard:

GTS Operation	Standard
Low	Data List value and fuel pressure gauge are within +/-50 kPag of each other
High

HINT:

Perform "Inspection After Repair" after replacing the No. 2 fuel pressure sensor (for low pressure side).

Click here

NG

REPLACE NO. 2 FUEL PRESSURE SENSOR (FOR LOW PRESSURE SIDE)

OK

4.	READ VALUE USING GTS (FUEL PRESSURE)

(a) Enter the following menus.

Powertrain > Engine > Data List

Tester Display
Target Fuel Pressure (Low) / Target Fuel Pressure 2
Fuel Pressure (Low) / Fuel Pressure 2
Low Fuel Pressure Sensor

(b) Read the values displayed on the GTS while the engine is cranking.

Result	Proceed to
Low Fuel Pressure Sensor value is within +/- 65 kPag of the Target Fuel Pressure (Low) / Target Fuel Pressure 2	A
Low Fuel Pressure Sensor value is more than 65 kPag higher than the target fuel pressure (low) / Target Fuel Pressure 2	B
Low Fuel Pressure Sensor value is more than 65 kPag lower than the target fuel pressure (low) / Target Fuel Pressure 2	C

HINT:

Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

Click here

B

REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) HINT: Relief blockage such as clogging of the jet pump is suspected.

C

GO TO STEP 6

A

5.	CHECK FUEL PRESSURE

(a) Install the fuel pressure gauge (for low pressure line of low pressure side).

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(b) Put the engine in Inspection Mode (Maintenance Mode).

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(c) Start the engine.

(d) Measure the fuel pressure at idle.

Standard Fuel Pressure:

196 to 833 kPa (2.0 to 8.5 kgf/cm2, 28 to 121 psi)

HINT:

Refer to Standard Idle Speed.

Click here

(e) Stop the engine.

(f) Check that the fuel pressure remains as specified for 5 minutes.

Standard Fuel Pressure:

98 kPa (1.0 kgf/cm2, 14.2 psi) or more

HINT:

Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

Click here

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE)

6.	CHECK SHORTAGE OF FUEL

(a) Check the amount of fuel remaining.

HINT:

• No fuel remains in the fuel tank: Malfunction of the fuel sender gauge assembly is suspected.
• Only the fuel pump side fuel chamber has no fuel remaining: Malfunction of the jet pump is suspected.
• Fuel remains in the fuel tank: Malfunction of the fuel pump (for low pressure side) is suspected.
• Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

  Click here

NEXT

7.	REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE)

Click here

NEXT

END

8.	PERFORM ACTIVE TEST USING GTS (FUEL PUMP SINGLE PHASE ENERGIZATION)

*a	Front view of wire harness connector (to Fuel Pump (for low pressure side))

(a) Disconnect the fuel pump (for low pressure side) connector.

(b) Enter the following menus.

Powertrain > Engine > Active Test

Tester Display
Fuel Pump Single Phase Energization

(c) Operate the fuel pump control ECU using the Active Test function and measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	GTS Operation	Specified Condition
O220-3 (BLPU) - Body ground	U Phase	4.4 to 8.4 V*
O220-4 (BLPV) - Body ground	V Phase	4.4 to 8.4 V*
O220-2 (BLPW) - Body ground	W Phase	4.4 to 8.4 V*

HINT:

• *: This Active Test restricts the fuel pump control ECU output duty cycle to 50%. Therefore, the output voltage of the fuel pump control ECU will be approximately 50% of the power source voltage.
• Before performing this inspection, check that the auxiliary battery voltage is between 11 and 14 V (not depleted).
• Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

  Click here

NG

GO TO STEP 10

OK

9.	REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE)

Click here

NEXT

END

10.	CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU - FUEL PUMP (FOR LOW PRESSURE SIDE))

(a) Disconnect the fuel pump control ECU connector.

(b) Disconnect the fuel pump (for low pressure side) connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O67-2 (FPU) - O220-3 (BLPU)	Always	Below 1 Ω
O67-3 (FPV) - O220-4 (BLPV)	Always	Below 1 Ω
O67-4 (FPW) - O220-2 (BLPW)	Always	Below 1 Ω
O67-2 (FPU) or O220-3 (BLPU) - Body ground and other terminals	Always	10 kΩ or higher
O67-3 (FPV) or O220-4 (BLPV) - Body ground and other terminals	Always	10 kΩ or higher
O67-4 (FPW) or O220-2 (BLPW) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

11.	CHECK HARNESS AND CONNECTOR (POWER SOURCE OF FUEL PUMP CONTROL ECU)

*a	Front view of wire harness connector (to Fuel Pump Control ECU)

(a) Disconnect the fuel pump control ECU connector.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection	Switch Condition	Specified Condition
O66-1 (+B) - O66-3 (GND)	Ignition switch ON	11 to 14 V

NG

GO TO STEP 14

OK

12.	INSPECT ECM (FPC TERMINAL)

*a	Front view of wire harness connector (to Fuel Pump Control ECU)

(a) Disconnect the fuel pump control ECU connector.

(b) Enter the following menus.

Powertrain > Engine > Active Test

Tester Display
Fuel Pump Single Phase Energization

(c) Operate the fuel pump control ECU using the Active Test function and measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	GTS Operation	Specified Condition
O66-2 (FPC) - Body ground	Before Active Test → During Active Test	Before Active Test: Resistance is stable → During Active Test: Resistance fluctuates*

HINT:

*: Using the Active Test, duty control of the transistors in the ECM will be performed. Due to the duty control, resistance of the FPC terminal will be unstable during the Active Test. If the resistance is stable before the Active Test and fluctuates while performing the Active Test, it can be determined that the transistor is operating. If the transistor does not operate during the Active Test, the ECM may be malfunctioning.

OK

REPLACE FUEL PUMP CONTROL ECU

NG

13.	CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU - ECM)

(a) Disconnect the fuel pump control ECU connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O66-2 (FPC) - A47-16 (FPC)	Always	Below 1 Ω
O66-2 (FPC) or A47-16 (FPC) - Body ground and other terminals	Always	10 kΩ or higher

OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

14.	CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU - BODY GROUND)

(a) Disconnect the fuel pump control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
O66-3 (GND) - Body ground	Always	Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

15.	CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE OF EFI-MAIN NO. 2 RELAY)

(a) Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
3 (EFI-MAIN NO. 2 relay) - Body ground	Always	11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - EFI-MAIN NO. 2 RELAY)

OK

16.	INSPECT EFI-MAIN NO. 2 RELAY

(a) Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

(b) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition 3 - 5 Auxiliary battery voltage not applied between terminals 1 and 2 10 kΩ or higher Auxiliary battery voltage applied between terminals 1 and 2 Below 1 Ω

*1 EFI-MAIN NO. 2 Relay

(c) Install the EFI-MAIN NO. 2 relay.

NG

REPLACE EFI-MAIN NO. 2 RELAY

OK

17.	CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 1 RELAY - EFI-MAIN NO. 2 RELAY)

(a) Remove the EFI-MAIN NO. 1 relay and EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

(b) Remove the VVT relay and EFI-MAIN NO. 3 relay from the No. 1 engine room relay block.

HINT:

Remove the VVT relay and EFI-MAIN NO. 3 relay connected between the checked terminals as the coil inside the relay influences the measurement value.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 (EFI-MAIN NO. 1 relay) - 1 (EFI-MAIN NO. 2 relay)	Always	Below 1 Ω
3 (EFI-MAIN NO. 1 relay) or 1 (EFI-MAIN NO. 2 relay) - Body ground and other terminals	Always	10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

18.	CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 2 RELAY - BODY GROUND)

(a) Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
2 (EFI-MAIN NO. 2 relay) - Body ground	Always	Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

19.	CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 2 RELAY - FUEL PUMP CONTROL ECU)

(a) Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

(b) Disconnect the fuel pump control ECU connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
5 (EFI-MAIN NO. 2 relay) - O66-1 (+B)	Always	Below 1 Ω
5 (EFI-MAIN NO. 2 relay) or O66-1 (+B) - Body ground and other terminals	Always	10 kΩ or higher

OK

GO TO ECM POWER SOURCE CIRCUIT

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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