| Last Modified: 11-27-2007 | 1.6 J | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM0000030MH00HX |
| Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 LX570) | ||
|
Fuel Pump Control Circuit |
DESCRIPTION
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.
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
.
PROCEDURE
|
1. |
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.
|
|
2. |
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 |
|
M2-1 (FP-) - Body ground |
Always |
10 kΩ or higher |
|
|
3. |
REPLACE FUEL PUMP ECU |
(a) Replace the fuel pump ECU
.
|
|
4. |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
(a) Check the fuel pump operation.
OK:
Malfunction has been repaired successfully.
|
|
5. |
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 |
|
|
6. |
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 |
|
|
7. |
CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY - ECU, 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 |
|
|
8. |
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 |
|
|
9. |
INSPECT FUEL PUMP |
(a) Inspect the fuel pump
.
|
|
10. |
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 |
|
|
11. |
REPLACE FUEL PUMP ECU |
(a) Replace the fuel pump ECU
.
|
|
12. |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
(a) Check the fuel pump operation.
OK:
Malfunction has been repaired successfully.
|
|
13. |
CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING 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 |
|
|
14. |
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 |
|
|
15. |
CHECK HARNESS AND CONNECTOR (EFI NO. 2 RELAY - INTEGRATION RELAY, BATTERY AND 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 positive (+) battery 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 |
|
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