Home Engine/Hybrid System Engine Control 3UR-FE ENGINE CONTROL: SFI SYSTEM
Last Modified: 11-27-2007 1.6 C
Service Category: Engine/Hybrid System Section: Engine Control
Model Year: 2008 Model: LX570 Doc ID: RM000000T8X041X
Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 LX570)

DTC

P0230

Fuel Pump Primary Circuit

DESCRIPTION

When a malfunction in the fuel pump circuit is detected, DTC P0230 is stored.

The fuel pump circuit consists of the ECM, fuel pump and fuel pump ECU (which operates the fuel pump). 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 ECU. Based on the signal sent from the ECM, the fuel pump ECU adjusts the fuel pump operation speed between 3 settings. The fuel pump ECU also has a self-diagnosis function. Based on the fuel pump circuit condition, the fuel pump ECU outputs a diagnostic signal (DI) to the ECM, and the ECM determines if there is a malfunction in the fuel pump circuit.

DTC Code

DTC Detection Condition

Trouble Area

P0230

When either condition below is met (1 trip detection logic):

  • When the fuel pump is operating:
    • The remaining fuel is 17 L or more.
    • The DI terminal output is low.
  • When the fuel pump is not operating:
    • The DI terminal output is high.
  • Open or short in fuel pump circuit
  • Fuel pump
  • Fuel pump ECU
  • ECM

MONITOR DESCRIPTION

To monitor the fuel pump circuit, the ECM checks the fuel pump control signal (FPC) and diagnostic signal (DI). The FPC voltage varies between approximately 0 V to approximately 12 V (duty signal). Based on the condition of the fuel pump ECU malfunction, the DI voltage varies between approximately 0 V and approximately 12 V. The ECM then compares the variance of the FPC voltage and DI voltage, and determines if the fuel pump circuit is malfunctioning. When the ECM determines that the fuel pump circuit is malfunctioning, a DTC is stored immediately.

WIRING DIAGRAM



INSPECTION PROCEDURE

This troubleshooting procedure is based on the premise that the engine is started. If the engine is not started, proceed to the Problem Symptoms Table 3UR-FE ENGINE CONTROL: SFI SYSTEM: PROBLEM SYMPTOMS TABLE (2008 LX570) .

PROCEDURE

1.

CHECK FOR DTC (B1500)

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Combination Meter / Trouble Codes.

(e) Read the DTC.

Result

Result

Proceed to

DTC B1500 is not output

A

DTC B1500 is output

B

A

2.

PERFORM ACTIVE TEST USING TECHSTREAM (FUEL PUMP)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG) and turn the Techstream on.

(c) Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Fuel Pump / Speed.

(d) Check whether operating sounds can be heard while operating the fuel pump using the Techstream.

OK:

Operating sounds can be heard from fuel pump.

OK

3.

CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM, BODY GROUND)



(a) Disconnect the N2 fuel pump ECU connector.

(b) Disconnect the A38 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

N2-5 (FPC) - A38-52 (FPC)

Always

Below 1 Ω

N2-4 (DI) - A38-18 (DI)

Always

Below 1 Ω

N2-6 (E) - Body ground

Always

Below 1 Ω

N2-1 (FP-) - Body ground

Always

10 kΩ or higher

N2-5 (FPC) or A38-52 (FPC) - Body ground

Always

10 kΩ or higher

N2-4 (DI) or A38-18 (DI) - Body ground

Always

10 kΩ or higher

OK

4.

REPLACE FUEL PUMP ECU

(a) Replace the fuel pump ECU 3UR-FE FUEL: FUEL PUMP ECU: REMOVAL (2008 LX570) .

NEXT

5.

CONFIRM WHETHER DTC OUTPUT RECURS

(a) Check that there are 17 liters or more of fuel remaining.

(b) Connect the Techstream to the DLC3.

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

(d) Turn the Techstream on.

(e) Clear DTCs 3UR-FE ENGINE CONTROL: SFI SYSTEM: DTC CHECK / CLEAR (2008 LX570) .

(f) Crank the engine for 15 seconds.

(g) Idle it for 1 minute.

(h) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(i) Read the DTCs.

Result

Result

Proceed to

DTC is not output

A

DTC P0230 is output

B

A

7.

INSPECT CIRCUIT OPENING RELAY (C/OPN)



(a) Remove the circuit opening relay (C/OPN) from the 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

No battery voltage applied to terminals 1 and 2

10 kΩ or higher

3 - 5

Battery voltage applied to terminals 1 and 2

Below 1 Ω

OK

8.

INSPECT CIRCUIT OPENING RELAY (POWER SOURCE VOLTAGE)



(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.

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

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

C/OPN relay (2) - Body ground

Engine switch on (IG)

11 to 14 V

C/OPN relay (5) - Body ground

Engine switch on (IG)

11 to 14 V

OK

9.

CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - ECM, FUEL PUMP ECU)



(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.

(b) Disconnect the A38 ECM connector.

(c) Disconnect the N2 fuel pump ECU connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C/OPN relay (1) - A38-48 (FC)

Always

Below 1 Ω

C/OPN relay (3) - N2-3 (+B)

Always

Below 1 Ω

C/OPN relay (1) or A38-48 (FC) - Body ground

Always

10 kΩ or higher

C/OPN relay (3) or N2-3 (+B) - Body ground

Always

10 kΩ or higher

OK

10.

CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP ECU)



(a) Disconnect the N1 fuel pump connector.

(b) Disconnect the N2 fuel pump ECU connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

N1-4 (B2) - N2-2 (FP)

Always

Below 1 Ω

N1-5 (E2) - N2-1 (FP-)

Always

Below 1 Ω

N1-4 (B2) or N2-2 (FP) - Body ground

Always

10 kΩ or higher

N1-5 (E2) or N2-1 (FP-) - Body ground

Always

10 kΩ or higher

OK

11.

INSPECT FUEL PUMP

(a) Inspect the fuel pump 3UR-FE FUEL: FUEL PUMP: INSPECTION (2008 LX570)+ .

OK

12.

CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM, BODY GROUND)



(a) Disconnect the N2 fuel pump ECU connector.

(b) Disconnect the A38 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

N2-5 (FPC) - A38-52 (FPC)

Always

Below 1 Ω

N2-4 (DI) - A38-18 (DI)

Always

Below 1 Ω

N2-6 (E) - Body ground

Always

Below 1 Ω

N2-5 (FPC) or A38-52 (FPC) - Body ground

Always

10 kΩ or higher

N2-4 (DI) or A38-18 (DI) - Body ground

Always

10 kΩ or higher

OK

13.

REPLACE FUEL PUMP ECU

(a) Replace the fuel pump ECU 3UR-FE FUEL: FUEL PUMP ECU: REMOVAL (2008 LX570) .

NEXT

14.

CONFIRM WHETHER DTC OUTPUT RECURS

(a) Check that there is 17 liters or more of fuel remaining.

(b) Connect the Techstream to the DLC3.

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

(d) Turn the Techstream on.

(e) Clear DTCs 3UR-FE ENGINE CONTROL: SFI SYSTEM: DTC CHECK / CLEAR (2008 LX570) .

(f) Crank the engine for 15 seconds.

(g) Idle it for 1 minute.

(h) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(i) Read the DTCs.

Result

Result

Proceed to

DTC is not output

A

DTC P0230 is output

B

A

16.

CHECK HARNESS AND CONNECTOR (C/OPN RELAY - EFI NO. 2 RELAY, IGN FUSE)



(a) Remove the circuit opening relay (C/OPN) from the engine room relay block.

(b) Remove the EFI NO. 2 relay (EFI NO. 2) from the engine room relay block.

(c) Remove the IGN fuse from the engine room relay block.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C/OPN relay (2) - IGN fuse (2)

Always

Below 1 Ω

C/OPN relay (5) - EFI NO. 2 relay (3)

Always

Below 1 Ω

C/OPN relay (2) or IGN fuse (2) - Body ground

Always

10 kΩ or higher

C/OPN relay (5) or EFI NO. 2 relay (3) - Body ground

Always

10 kΩ or higher

OK

17.

INSPECT EFI NO. 2 RELAY (EFI NO. 2)



(a) Remove the EFI NO. 2 relay (EFI NO. 2) from the 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

No battery voltage applied to terminals 1 and 2

10 kΩ or higher

3 - 5

Battery voltage applied to terminals 1 and 2

Below 1 Ω

OK

18.

CHECK HARNESS AND CONNECTOR (EFI NO. 2 RELAY - INTEGRATION RELAY, BATTERY, BODY GROUND)



(a) Remove the EFI MAIN 2 fuse from the engine room relay block.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

EFI MAIN 2 fuse

Always

Below 1 Ω

(c) Reinstall the EFI MAIN 2 fuse.

(d) Remove the EFI NO. 2 relay (EFI NO. 2) from the engine room relay block.

(e) Remove the integration relay from the engine room relay block.

(f) Disconnect the 1B integration relay connector.

(g) Disconnect the cable from the battery positive (+) terminal.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

EFI NO. 2 relay (1) - 1B-4

Always

Below 1 Ω

EFI NO. 2 relay (5) - Positive (+) battery cable

Always

Below 1 Ω

EFI NO. 2 relay (2) - Body ground

Always

Below 1 Ω

EFI NO. 2 relay (1) or 1B-4 - Body ground

Always

10 kΩ or higher

EFI NO. 2 relay (5) or Positive (+) battery cable - Body ground

Always

10 kΩ or higher

OK