DESCRIPTION
The VC voltage (5 V) is generated in the ECM. The voltage is used to supply power to the throttle position sensor (throttle body assembly), EGR valve position sensor (electric EGR control valve assembly), manifold absolute pressure sensor, accelerator pedal position sensor (accelerator pedal rod assembly) and fuel pressure sensor.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
CHECK MIL
Check that the Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch to ON.
| OK |
|---|
| MIL lights up |
| OK |
|
SYSTEM OK |
| NG |
|
CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON and the tester on.
Check the communication between the intelligent tester and ECM.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
| B |
|
GO TO MIL CIRCUIT |
| A |
|
CHECK ECM (VC VOLTAGE)
| *a | Component with harness connected (ECM) |
Turn the ignition switch to ON.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| NEXT |
|
CHECK MIL (THROTTLE POSITION SENSOR)
Disconnect the D50 throttle position sensor connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| MIL does not illuminate | A |
| MIL illuminates | B |
Reconnect the throttle position sensor connector.
| B |
|
REPLACE DIESEL THROTTLE BODY ASSEMBLY |
| A |
|
CHECK MIL (MANIFOLD ABSOLUTE PRESSURE SENSOR)
Disconnect the D51 manifold absolute pressure sensor connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| MIL does not illuminate | A |
| MIL illuminates | B |
Reconnect the manifold absolute pressure sensor connector.
| B |
|
REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR |
| A |
|
CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)
Disconnect the B1 accelerator pedal position sensor connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| MIL does not illuminate | A |
| MIL illuminates | B |
Reconnect the accelerator position sensor connector.
| B |
|
REPLACE ACCELERATOR PEDAL ROD ASSEMBLY |
| A |
|
CHECK MIL (EGR VALVE POSITION SENSOR)
Disconnect the D52 EGR valve position sensor connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| MIL does not illuminate | A |
| MIL illuminates | B |
Reconnect the EGR valve position sensor connector.
| B |
|
REPLACE ELECTRIC EGR CONTROL VALVE ASSEMBLY |
| A |
|
CHECK MIL (FUEL PRESSURE SENSOR)
Disconnect the D69 fuel pressure sensor connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| MIL does not illuminate | A |
| MIL illuminates | B |
Reconnect the fuel pressure sensor connector.
| B |
|
REPLACE COMMON RAIL ASSEMBLY |
| A |
|
CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)
Disconnect the D50 throttle position sensor connector.
Disconnect the D51 manifold absolute pressure sensor connector.
Disconnect the D69 fuel pressure sensor connector.
Disconnect the D52 EGR valve position sensor connector.
Disconnect the B1 accelerator pedal position sensor connector.
Disconnect the D75, D76 and B47 ECM connectors.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance (Check for Short) | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Reconnect the throttle position sensor connector.
Reconnect the manifold absolute pressure sensor connector.
Reconnect the fuel pressure sensor connector.
Reconnect the EGR valve position sensor connector.
Reconnect the accelerator pedal position sensor connector.
Reconnect the ECM connectors.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
REPLACE ECM