| Last Modified: 11-27-2007 | 1.6 J | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM000001DN801ZX |
| Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 LX570) | ||
|
ECM Power Source Circuit |
DESCRIPTION
When the engine switch is turned on (IG), the battery voltage is applied to the IGSW of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil, closing the contacts of the integration relay (EFI relay) and supplying power to either terminal +B or +B2 of the ECM.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
INSPECT FUSES (IG2 MAIN, EFI MAIN AND IGN) |
(a) Remove the IG2 MAIN fuse, EFI MAIN fuse and IGN 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 |
|---|---|---|
|
IG2 MAIN fuse |
Always |
Below 1 Ω |
|
EFI MAIN fuse |
Always |
Below 1 Ω |
|
IGN fuse |
Always |
Below 1 Ω |
|
|
2. |
INSPECT RELAY (IG2, EFI) |
(a) Remove the integration relay 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 |
|---|---|---|
|
1C-1 - 1B-8 |
No battery voltage applied to terminals 1B-6 and 1B-7 |
10 kΩ or higher |
|
1C-1 - 1B-8 |
Battery voltage applied to terminals 1B-6 and 1B-7 |
Below 1 Ω |
|
1C-1 - 1B-4 |
No battery voltage applied to terminals 1B-2 and 1B-3 |
10 kΩ or higher |
|
1C-1 - 1B-4 |
Battery voltage applied to terminals 1B-2 and 1B-3 |
Below 1 Ω |
|
|
3. |
CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) |
(a) Disconnect the C53 ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
C53-81 (E1) - Body ground |
Always |
Below 1 Ω |
|
|
4. |
CHECK HARNESS AND CONNECTOR (RELAY BLOCK - ECM, MAIN BODY ECU, BATTERY) |
(a) Disconnect the A38 ECM connector.
(b) Disconnect the E2 main body ECU connector.
(c) Disconnect the cable from the battery positive (+) terminal.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A38-28 (IGSW) - 1B-8 |
Always |
Below 1 Ω |
|
1B-7 - Body ground |
Always |
Below 1 Ω |
|
Positive (+) battery cable - 1C-1 |
Always |
Below 1 Ω |
|
E2-11 (IG2D) - 1B-6 |
Always |
Below 1 Ω |
|
A38-28 (IGSW) or 1B-8 - Body ground |
Always |
10 kΩ or higher |
|
Positive (+) battery cable or 1C-1 - Body ground |
Always |
10 kΩ or higher |
|
E2-11 (IG2D) or 1B-6 - Body ground |
Always |
10 kΩ or higher |
|
|
5. |
INSPECT ECM (IGSW VOLTAGE) |
(a) Disconnect the A38 and C53 ECM connectors.
(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 |
|---|---|---|
|
A38-28 (IGSW) - C53-81 (E1) |
Engine switch on (IG) |
11 to 14 V |
|
6. |
CHECK SMART ACCESS SYSTEM WITH PUSH-BUTTON START (POWER SOURCE MODE DOES NOT CHANGE) |
(a) Check the smart access system with push-button start
.
|
|
7. |
CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, BATTERY AND BODY GROUND) |
(a) Disconnect the A38 ECM connector.
(b) Disconnect the cable from the battery positive terminal.
(c) Remove the integration relay from the engine room relay block.
(d) Disconnect the integration relay connector.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A38-3 (+B) - 1B-4 |
Always |
Below 1 Ω |
|
A38-2 (+B2) - 1B-4 |
Always |
Below 1 Ω |
|
A38-34 (MREL) - 1B-2 |
Always |
Below 1 Ω |
|
1C-1 - Positive (+) battery cable |
Always |
Below 1 Ω |
|
1B-3 - Body ground |
Always |
Below 1 Ω |
|
A38-3 (+B) or 1B-4 - Body ground |
Always |
10 kΩ or higher |
|
A38-2 (+B2) or 1B-4 - Body ground |
Always |
10 kΩ or higher |
|
A38-34 (MREL) or 1B-2 - Body ground |
Always |
10 kΩ or higher |
|
1C-1 or Positive (+) battery cable - Body ground |
Always |
10 kΩ or higher |
|
|
|