Sfi System Vc Output Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK MIL
CHECK COMMUNICATION BETWEEN TECHSTREAM AND ECM
CHECK MIL (THROTTLE POSITION SENSOR)
CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)
CHECK MIL (CANISTER PUMP MODULE)
CHECK HARNESS AND CONNECTOR (VC CIRCUIT)
SFI SYSTEM - VC Output Circuit |
DESCRIPTION
The ECM constantly generates 5 V power from the battery voltage 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 when the ignition switch is turned ON. The MIL goes off when the engine is started.
WIRING DIAGRAM
INSPECTION PROCEDURE
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 |
Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
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) |
Disconnect the throttle body connector.
Turn the ignition switch to ON.
Check the MIL.
- Result:
Result
| Proceed to
|
MIL illuminates
| A
|
MIL does not illuminate
| B
|
Reconnect the throttle body connector.
4.CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR) |
Disconnect the accelerator pedal position sensor connector.
Turn the ignition switch to ON.
Check the MIL.
- Result:
Result
| Proceed to
|
MIL illuminates
| A
|
MIL does not illuminate
| B
|
Reconnect the accelerator pedal position sensor connector.
5.CHECK MIL (CANISTER PUMP MODULE) |
Disconnect the canister pump module connector.
Turn the ignition switch to ON.
Check the MIL.
- Result:
Result
| Proceed to
|
MIL illuminates
| A
|
MIL does not illuminate
| B
|
Reconnect the canister pump module connector.
6.CHECK HARNESS AND CONNECTOR (VC CIRCUIT) |
Disconnect the throttle body connector.
Disconnect the accelerator pedal position sensor connector.
Disconnect the canister pump module connector.
Disconnect the ECM connectors.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Short):
Tester Connection
| Condition
| Specified Condition
|
B31-67 (VCTA) - Body ground
| Always
| 10 kΩ or higher
|
A50-57 (VCPA) - Body ground
| Always
| 10 kΩ or higher
|
A50-58 (VCP2) - Body ground
| Always
| 10 kΩ or higher
|
B31-70 (VCPP) - Body ground
| Always
| 10 kΩ or higher
|
Reconnect the throttle body connector.
Reconnect the accelerator pedal position sensor connector.
Reconnect the canister pump module connector.
Reconnect the ECM connectors.
| REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|