| Last Modified: 11-29-2007 | 1.6 J | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000001D6V04YX |
| Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
VC Output Circuit |
DESCRIPTION
The ECM constantly generates 5 V power from the battery voltages supplied to the +B (BATT) terminal to operate the microprocessor. The ECM also provides this power to the sensors through the VC output circuit.
When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied with power through the VC circuit are inactivated because the power is not supplied from the VC circuit. Under this condition, the system does not start up and the MIL does not illuminate even if the system malfunctions.
HINT:
Under normal conditions, the MIL is illuminated for several seconds when the ignition switch is first turned to ON. The MIL goes off when the engine is started.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
CHECK MIL |
(a) Check that the Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch to ON.
OK:
MIL lights up
|
|
2. |
CHECK COMMUNICATION BETWEEN TECHSTREAM AND ECM |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Check the communication between the Techstream and ECM.
Result
|
Result |
Proceed to |
|---|---|
|
Communication is possible |
A |
|
Communication is not possible |
B |
|
|
3. |
CHECK MIL (THROTTLE POSITION SENSOR) |
(a) Disconnect the throttle body connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
4. |
CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR) |
(a) Disconnect the accelerator pedal position sensor connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
5. |
CHECK MIL (CANISTER PUMP MODULE) |
|
(a) Disconnect the canister pump module connector. |
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
6. |
CHECK MIL (AIR SWITCHING VALVE for Bank 1) |
(a) Disconnect the air switching valve connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
7. |
CHECK MIL (AIR SWITCHING VALVE for Bank 2) |
(a) Disconnect the air switching valve connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
8. |
CHECK MIL (POWER STEERING OIL PRESSURE SENSOR) |
(a) Disconnect the power steering oil pressure sensor connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
9. |
CHECK MIL (CAMSHAFT POSITION SENSOR) |
(a) Disconnect the camshaft position sensor connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
10. |
CHECK MIL (CRANKSHAFT POSITION SENSOR) |
(a) Disconnect the crankshaft position sensor connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
11. |
CHECK MIL (VVT SENSOR for Intake Side of Bank 1) |
(a) Disconnect the VVT sensor (for Intake Side of Bank 1) connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
12. |
CHECK MIL (VVT SENSOR for Exhaust Side of Bank 1) |
(a) Disconnect the VVT sensor (for Exhaust Side of Bank 1) connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
13. |
CHECK MIL (VVT SENSOR for Intake Side of Bank 2) |
(a) Disconnect the VVT sensor (for Intake Side of Bank 2) connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
14. |
CHECK MIL (VVT SENSOR for Exhaust Side of Bank 2) |
(a) Disconnect the VVT sensor (for Exhaust Side of Bank 2) connector.
(b) Turn the ignition switch to ON.
(c) Check the MIL.
Result
|
Result |
Proceed to |
|---|---|
|
MIL illuminates |
A |
|
MIL does not illuminate |
B |
|
|
15. |
CHECK HARNESS AND CONNECTOR |
(a) Disconnect the throttle body connector.
(b) Disconnect the accelerator pedal position sensor connector.
(c) Disconnect the canister pump module connector.
(d) Disconnect the air switching valve connector.
(e) Disconnect the air switching valve connector.
(f) Disconnect the power steering oil pressure sensor connector.
(g) Disconnect the camshaft position sensor connector.
(h) Disconnect the crankshaft position sensor connector.
(i) Disconnect the VVT sensor (for Intake Side of Bank 1) connector.
(j) Disconnect the VVT sensor (for Exhaust Side of Bank 1) connector.
(k) Disconnect the VVT sensor (for Intake Side of Bank 2) connector.
(l) Disconnect the VVT sensor (for Exhaust Side of Bank 2) connector.
|
(m) Disconnect the ECM connectors. |
(n) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
D56-80 (VCTA) - Body ground |
Always |
10 kΩ or higher |
|
A27-57 (VCPA) - Body ground |
Always |
10 kΩ or higher |
|
A27-59 (VCP2) - Body ground |
Always |
10 kΩ or higher |
|
D56-66 (VCV2) - Body ground |
Always |
10 kΩ or higher |
|
D56-67 (VCV1) - Body ground |
Always |
10 kΩ or higher |
|
|
|