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.
Tech Tips
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
CHECK MIL CONDITION
Check that the Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch to ON.
OK |
---|
MIL lights up. |
NG |
CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM Click here |
OK |
SYSTEM OK
CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the tester on.
Check for communication between the tester and ECM.
Result | Proceed to |
---|---|
Communication is possible | A |
Communication is not possible | B |
A |
GO TO MIL CIRCUIT Click here |
B |
CHECK MIL (THROTTLE POSITION SENSOR)
Disconnect the throttle body assembly connector.
Turn the ignition switch to ON.
Check the MIL.
Result | Proceed to |
---|---|
MIL illuminates | A |
MIL does not illuminate | B |
Reconnect the throttle body assembly connector.
A |
REPLACE THROTTLE BODY ASSEMBLY Click here |
B |
CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)
Disconnect the accelerator pedal position sensor connector.
Turn the ignition switch to ON.
Check the MIL.
Result | Proceed to |
---|---|
MIL illuminates | A |
MIL does not illuminate | B |
Reconnect the accelerator pedal position sensor connector.
A |
REPLACE ACCELERATOR PEDAL ASSEMBLY (ACCELERATOR PEDAL POSITION SENSOR) Click here |
B |
CHECK MIL (CAMSHAFT POSITION SENSOR (FOR INTAKE SIDE))
Disconnect the camshaft position sensor (for intake side) connector.
Turn the ignition switch to ON.
Check the MIL.
Result | Proceed to |
---|---|
MIL illuminates | A |
MIL does not illuminate | B |
Reconnect the camshaft position sensor (for intake side) connector.
A |
REPLACE CAMSHAFT POSITION SENSOR (FOR INTAKE SIDE) Click here |
B |
CHECK MIL (CAMSHAFT POSITION SENSOR (FOR EXHAUST SIDE))
Disconnect the camshaft position sensor (for exhaust side) connector.
Turn the ignition switch to ON.
Check the MIL.
Result | Proceed to |
---|---|
MIL illuminates | A |
MIL does not illuminate | B |
Reconnect the camshaft position sensor (for exhaust side) connector.
A |
REPLACE CAMSHAFT POSITION SENSOR (FOR EXHAUST SIDE) Click here |
B |
CHECK MIL (VACUUM SENSOR)
Disconnect the vacuum sensor connector.
Turn the ignition switch to ON.
Check the MIL.
Result | Proceed to |
---|---|
MIL illuminates | A |
MIL does not illuminate | B |
Reconnect the vacuum sensor connector.
A |
REPLACE VACUUM SENSOR Click here |
B |
CHECK HARNESS AND CONNECTOR
Disconnect the throttle body assembly connector.
Disconnect the accelerator pedal position sensor connector.
Disconnect the camshaft position sensor (for intake camshaft) connector.
Disconnect the camshaft position sensor (for exhaust camshaft) connector.
Disconnect the vacuum sensor connector.
*1 | Front view of wire harness connector (to ECM) |
*2 | Front view of wire harness connector (to ECM) |
Disconnect the ECM connectors.
Measure the resistance according to the value(s) in the table below.
Standard Resistance (Check for short) | |||||||||||||||||||||
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|
Reconnect the throttle body assembly connector.
Reconnect the accelerator pedal position sensor connector.
Reconnect the camshaft position sensor (for intake camshaft) connector.
Reconnect the camshaft position sensor (for exhaust camshaft) connector.
Reconnect the vacuum sensor connector.
Reconnect the ECM connectors.
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
REPLACE ECM Click here