VC Output Circuit

2AZ-FXE ENGINE CONTROL SYSTEM: SFI SYSTEM: VC Output Circuit

VC Output Circuit

DESCRIPTION

The ECM (Included in the hybrid vehicle control ECU) constantly generates 5 V power from the battery voltages supplied to the +B (BATT) terminal to operate the Micro-processor. The ECM also provides this power to the sensors through the VC output circuit.





When the VC circuit is short-circuited, the Micro-processor in the ECM (included in hybrid vehicle control ECU) and sensors that are supplied with power through the VC circuit are deactivated 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 power switch is first turned on. The MIL goes off when the hybrid vehicle is started.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK MIL
(a) Check that the Malfunction Indicator Lamp (MIL) lights up when turning the power switch on (IG).
OK:
MIL lights up
OK -- SYSTEM IS OK
NG -- Continue to next step.
2. CHECK COMMUNICATION BETWEEN TECHSTREAM AND HYBRID VEHICLE CONTROL ECU
(a) Connect the Techstream to the DLC3.
(b) Turn the power switch on (IG) and tester on.
(c) Check the communication between the tester and hybrid vehicle control ECU.
Result:






A -- GO TO MIL CIRCUIT
B -- Continue to next step.
3. CHECK MIL (THROTTLE POSITION SENSOR)
(a) Disconnect the C5 throttle body connector.
(b) Turn the power switch on (IG).
(c) Check the MIL.
Result:





(d) Reconnect the throttle body connector.
A -- REPLACE THROTTLE BODY ASSEMBLY
B -- Continue to next step.
4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)
(a) Disconnect the A17 accelerator pedal position sensor connector.
(b) Turn the power switch on (IG).
(c) Check the MIL.
Result:





(d) Reconnect the accelerator pedal position sensor connector.
A -- REPLACE ACCELERATOR PEDAL POSITION SENSOR
B -- Continue to next step.
5. CHECK MIL (CANISTER PUMP MODULE)




(a) Disconnect the N17 canister pump module connector.
(b) Turn the power switch on (IG).
(c) Check the MIL.
Result:





(d) Reconnect the canister pump module connector.
A -- REPLACE CHARCOAL CANISTER ASSEMBLY
B -- Continue to next step.
6. CHECK MIL (FUEL TANK PRESSURE SENSOR)
(a) Disconnect the N35 vapor pressure sensor connector.
(b) Turn the power switch on (IG).
(c) Check the MIL.
Result:






A -- REPLACE FUEL TANK PRESSURE SENSOR
B -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR
(a) Disconnect the C5 throttle body connector.
(b) Disconnect the A17 accelerator pedal position sensor connector.
(c) Disconnect the N17 canister pump module connector.
(d) Disconnect the N35 vapor pressure sensor connector.




(e) Disconnect the A61 and C64 hybrid vehicle control ECU connectors.
(f) Measure the resistance.
Standard resistance (Check for short):





(g) Reconnect the throttle body connector.
(h) Reconnect the accelerator pedal position sensor connector.
(i) Reconnect the canister pump module connector.
(j) Reconnect the fuel tank pressure sensor connector.
(k) Reconnect the hybrid vehicle control ECU connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE HYBRID VEHICLE CONTROL ECU