| Last Modified: 11-29-2007 | 1.6 J | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000001DN8023X |
| Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
ECM Power Source Circuit |
DESCRIPTION
When the ignition switch is turned to ON, 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 MAIN relay) and supplying power to either terminal +B or +B2 of the ECM.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
INSPECT FUSES (AM2, IG2 MAIN, EFI NO. 1, IGN) |
(a) Remove the AM2 fuse, IG2 MAIN fuse, EFI NO. 1 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 |
|---|---|---|
|
AM2 fuse |
Always |
Below 1 Ω |
|
IG2 MAIN fuse |
Always |
Below 1 Ω |
|
EFI NO. 1 fuse |
Always |
Below 1 Ω |
|
IGN fuse |
Always |
Below 1 Ω |
|
|
2. |
INSPECT RELAY (IG2, EFI MAIN) |
(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 |
When no battery voltage is applied to terminals 1B-6 and 1B-7 |
10 kΩ or higher |
|
1C-1 - 1B-8 |
When battery voltage is applied to terminals 1B-6 and 1B-7 |
Below 1 Ω |
|
1C-1 - 1B-4 |
When no battery voltage is applied to terminals 1B-2 and 1B-3 |
10 kΩ or higher |
|
1C-1 - 1B-4 |
When battery voltage is applied to terminals 1B-2 and 1B-3 |
Below 1 Ω |
|
|
3. |
CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) |
(a) Disconnect the ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D56-81 (E1) - Body ground |
Always |
Below 1 Ω |
|
|
4. |
INSPECT ECM (IGSW VOLTAGE) |
(a) Disconnect the ECM connectors.
(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 |
|---|---|---|
|
A27-28 (IGSW) - D56-81 (E1) |
Ignition switch ON |
11 to 14 V |
|
|
5. |
CHECK HARNESS AND CONNECTOR (RELAY BLOCK - ECM, IGNITION SWITCH, BATTERY AND BODY GROUND) |
(a) Disconnect the ECM connector.
(b) Disconnect the ignition switch connector.
(c) Disconnect the cable from the battery positive (+) terminal.
(d) Remove the AM2 fuse and integration relay.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A27-28 (IGSW) - 1B-8 |
Always |
Below 1 Ω |
|
1B-7 - Body ground |
Always |
Below 1 Ω |
|
Positive (+) battery cable - 1C-1 |
Always |
Below 1 Ω |
|
Positive (+) battery cable - AM2 fuse terminal 1 |
Always |
Below 1 Ω |
|
H10-5 (AM2) - AM2 fuse terminal 2 |
Always |
Below 1 Ω |
|
H10-6 (IG2) - 1B-6 |
Always |
Below 1 Ω |
|
A27-28 (IGSW) or 1B-8 - Body ground |
Always |
10 kΩ or higher |
|
Positive (+) battery cable or AM2 fuse terminal 1 - Body ground |
Always |
10 kΩ or higher |
|
Positive (+) battery cable or 1C-1 - Body ground |
Always |
10 kΩ or higher |
|
H10-5 (AM2) or AM2 fuse terminal 2 - Body ground |
Always |
10 kΩ or higher |
|
H10-6 (IG2) or 1B-6 - Body ground |
Always |
10 kΩ or higher |
|
|
6. |
INSPECT IGNITION SWITCH
|
|
|
7. |
CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, BATTERY AND BODY GROUND) |
(a) Disconnect the 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 |
|---|---|---|
|
A27-3 (+B) - 1B-4 |
Always |
Below 1 Ω |
|
A27-2 (+B2) - 1B-4 |
Always |
Below 1 Ω |
|
A27-34 (MREL) - 1B-2 |
Always |
Below 1 Ω |
|
1C-1 - Positive (+) battery cable |
Always |
Below 1 Ω |
|
1B-3 - Body ground |
Always |
Below 1 Ω |
|
A27-3 (+B) or 1B-4 - Body ground |
Always |
10 kΩ or higher |
|
A27-2 (+B2) or 1B-4 - Body ground |
Always |
10 kΩ or higher |
|
A27-34 (MREL) or 1B-2 - Body ground |
Always |
10 kΩ or higher |
|
1C-1 or Positive (+) battery cable - Body ground |
Always |
10 kΩ or higher |
|
|
|