DESCRIPTION
The ECM constantly generates 5 V of 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 has a short circuit, the CPU in the ECM and sensors that are supplied power through the VC circuit are deactivated because power is not supplied from the VC circuit. When the system is in this condition, it will not start.
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
For the circuit diagram of the ECM power source circuit Click here
VC Power Source Circuit
CAUTION / NOTICE / HINT
Note
Check the fuses for circuits related to this system before performing the following inspection procedure.
After replacing the ECM, the new ECM needs registration (See page ) and initialization Click here.
PROCEDURE
CHECK COMMUNICATION BETWEEN GTS AND ECM
Connect the GTS to the DLC3.
Turn the ignition switch to ON and GTS on.
Check the communication between the GTS and ECM.
| Result | Proceed to |
|---|---|
| Communication is not possible | A |
| Communication is possible | B |
| B |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
| A |
|
CHECK TERMINAL VOLTAGE (POWER SOURCE OF ECM)
| *1 | Engine Room Relay Block |
| *2 | EFI No. 2 Fuse |
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
Tech Tips
If the result is not as specified, since current is not flowing to the +B and +B2 terminals of the ECM, the system may not be started.
| NG |
|
GO TO ECM POWER SOURCE CIRCUIT |
| OK |
|
CHECK CONNECTION BETWEEN GTS AND ECM (THROTTLE POSITION SENSOR (for Bank 1))
Disconnect the throttle position sensor (for Bank 1) connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the throttle position sensor (for Bank 1) connector.
| A |
|
REPLACE DIESEL THROTTLE BODY ASSEMBLY (for Bank 1) Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (THROTTLE POSITION SENSOR (for Bank 2))
Disconnect the throttle position sensor (for Bank 2) connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the throttle position sensor (for Bank 2) connector.
| A |
|
REPLACE DIESEL THROTTLE BODY ASSEMBLY (for Bank 2) Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (NO. 1 EGR VALVE POSITION SENSOR)
Disconnect the No. 1 EGR valve connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the No. 1 EGR valve connector.
| A |
|
REPLACE NO. 1 EGR VALVE ASSEMBLY Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (NO. 2 EGR VALVE POSITION SENSOR)
Disconnect the No. 2 EGR valve connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the No. 2 EGR valve connector.
| A |
|
REPLACE NO. 2 EGR VALVE ASSEMBLY Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (ACCELERATOR PEDAL POSITION SENSOR)
Disconnect the accelerator pedal position sensor connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the accelerator pedal position sensor connector.
| A |
|
REPLACE ACCELERATOR PEDAL ROD ASSEMBLY Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (MANIFOLD ABSOLUTE PRESSURE SENSOR)
Disconnect the manifold absolute pressure sensor connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the manifold absolute pressure sensor connector.
| A |
|
REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (FUEL PRESSURE SENSOR)
Disconnect the fuel pressure sensor connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the fuel pressure sensor connector.
| A |
|
REPLACE COMMON RAIL (for Bank 1) Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (DIFFERENTIAL PRESSURE SENSOR ASSEMBLY (for Bank 1))
Disconnect the differential pressure sensor assembly (for Bank 1) connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the differential pressure sensor assembly (for Bank 1) connector.
| A |
|
REPLACE DIFFERENTIAL PRESSURE SENSOR (for Bank 1) Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (DIFFERENTIAL PRESSURE SENSOR ASSEMBLY (for Bank 2))
Disconnect the differential pressure sensor assembly (for Bank 2) connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the differential pressure sensor assembly (for Bank 2) connector.
| A |
|
REPLACE DIFFERENTIAL PRESSURE SENSOR (for Bank 2) Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (NOZZLE VANE POSITION SENSOR (for Bank 1))
Disconnect the nozzle vane position sensor (for Bank 1) connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the nozzle vane position sensor (for Bank 1) connector.
| A |
|
REPLACE TURBOCHARGER SUB-ASSEMBLY (for Bank 1) Click here |
| B |
|
CHECK CONNECTION BETWEEN GTS AND ECM (NOZZLE VANE POSITION SENSOR (for Bank 2))
Disconnect the nozzle vane position sensor (for Bank 2) connector.
Turn the ignition switch to ON.
Check the MIL.
| Result | Proceed to |
|---|---|
| Communication is possible | A |
| Communication is not possible | B |
Reconnect the nozzle vane position sensor (for Bank 2) connector.
| A |
|
REPLACE TURBOCHARGER SUB-ASSEMBLY (for Bank 2) Click here |
| B |
|
CHECK HARNESS AND CONNECTOR
Disconnect the throttle position sensor (for Bank 1) connector.
Disconnect the throttle position sensor (for Bank 2) connector.
Disconnect the No. 1 EGR valve connector.
Disconnect the No. 2 EGR valve connector.
Disconnect the accelerator pedal position sensor connector.
Disconnect the manifold absolute pressure sensor connector.
Disconnect the fuel pressure sensor connector.
Disconnect the differential pressure sensor assembly (for Bank 1) connector.
Disconnect the differential pressure sensor assembly (for Bank 2) connector.
Disconnect the nozzle vane position sensor (for Bank 1) connector.
Disconnect the nozzle vane position sensor (for Bank 2) connector.
Disconnect the ECM connectors.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance (Check for Short) | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||||||||||||||||
|
Reconnect the throttle position sensor (for Bank 1) connector.
Reconnect the throttle position sensor (for Bank 2) connector.
Reconnect the No. 1 EGR valve connector.
Reconnect the No. 2 EGR valve connector.
Reconnect the accelerator pedal position sensor connector.
Reconnect the manifold absolute pressure sensor connector.
Reconnect the fuel pressure sensor connector.
Reconnect the differential pressure sensor assembly (for Bank 1) connector.
Reconnect the differential pressure sensor assembly (for Bank 2) connector.
Reconnect the nozzle vane position sensor (for Bank 1) connector.
Reconnect the nozzle vane position sensor (for Bank 2) connector.
Reconnect the ECM connectors.
| OK |
|
REPLACE ECM Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |