The engine control module (ECM) performs the turbocharger (TC) learn procedure automatically when the enabling criteria have been met. After each ignition cycle, and before the enable criteria have been met, the ECM will use the previously learned value. If the ECM does not have a previously learned value, it will default to a stored calibrated value.

The ECM commands the TC vane control solenoid to position the TC vanes, and a TC vane position sensor monitors the actual position of the vanes. The ECM varies the boost dependant upon the load requirements of the engine.

The vane control solenoid has 2 circuits; a high voltage control circuit and a low voltage control circuit. The ECM uses a pulse width modulation (PWM) on both circuits to control the solenoid.

The TC Learn can also detect sticking vanes, sticking control solenoid, or position sensor errors. During the TC Learn, the ECM commands the vanes to 0 percent, then to 100 percent, while comparing the actual and desired TC vane position values. If the difference between the values is greater than or less than , a calibrated threshold, the automatic learn fails.

DTC P003A is a Type B DTC.

DTC P003A is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 34730-405 Injector Test Lamp

1. Verify that DTCs P0047, P0048, P0652, P0653, P0698, P0699, P2564, or P2565 are not set.

⇒	If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.

2. Engine running, increase the engine speed to 1,500 RPM and maintain. Command the TC Vane Pos. Ctrl. Solenoid ON and OFF with a scan tool. Observe the Vane Position Sensor parameter. The TC Vane Position Sensor parameter should increase to 95-99 percent and decrease to near 0 percent when commanded ON and OFF.
3. Engine running, observe the TC Vane position Sensor and the Desired TC Vane Position parameters with a scan tool. Slowly increase the engine speed from idle to 2,500 RPM, and slowly return the engine to idle speed. The TC Vane Position Sensor parameter should remain near or equal to the Desired TC Vane Position parameter throughout the engine speed range.
4. Engine running, observe the TC Vane Position Sensor and the Desired TC Vane Position parameters while increasing the TC vane position in 5 percent increments from 0-100 percent with a scan tool. The parameters should remain within 2 percent of each other during the entire range.
5. Operate the vehicle within the Conditions for Running the DTC to verify that the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, for 90 seconds, disconnect the harness connector at the TC control solenoid.
2. Connect the J 34730-405 between the high control terminal A and the low control circuits terminal B.

Important: When the engine coolant temperature is less than 70°C (158°F), the test lamp will change brightness when commanded with a scan tool. When the ECM is attempting a TC Learn, the test lamp will flash ON and OFF without commands from a scan tool.

3. Engine running, engine coolant temperature (ECT) sensor 1 must be less than 70°C (158°F). Command the TC Vane Pos. Ctrl. solenoid ON and OFF with a scan tool. The test lamp should illuminate and change from bright to dim when changing between the commanded states.

⇒	If the test lamp does not illuminate, test the low control circuit terminal B for an open/high resistance or a short to voltage. If the circuit tests normal, test the high control circuit terminal A for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM.

⇒	If the test lamp remains illuminated, test the low control circuit terminal B for a short to ground.

Important: The resistance of the TC control solenoid will vary with the temperature.

4. Ignition OFF, measure the resistance of the TC control solenoid. The reading should be between 3-7 ohms.

⇒	If the resistance is not within the specified range, replace the TC control solenoid.

5. Test for infinite resistance between each TC control solenoid terminal and the TC control solenoid housing.

⇒	If less than infinite resistance, replace the TC control solenoid.

6. Disconnect the harness connectors at the ECM, and TC vane position sensor.
7. Test for less than 5 ohms on all turbocharger sensor and solenoid circuits between the following terminals:

•	The ECM X1 TC solenoid high control circuit terminal 48 to TC control solenoid terminal A.

•	The ECM X1 TC solenoid low control circuit terminal 96 to TC control solenoid terminal B.

•	The ECM X1 TC sensor signal circuit terminal 20 to TC position sensor terminal B.

•	The ECM X1 TC sensor low reference terminal 63 to TC position sensor terminal C.

•	The ECM X1 TC sensor 5-volt reference terminal 13 to TC position sensor terminal D.

⇒	If greater than the specified range, repair the high resistance in the affected circuit.

8. Connect the ECM connectors. Test the TC vane position sensor. Refer to Component Testing in this document for instructions.
9. Install and connect the TC vane position sensor.
10. Command the turbocharger TC Vane Position Sensor from 0 percent to 100 percent while observing the TC Vane Position Sensor Volts parameter. The voltage should increment smoothly and gradually from approximately 1.0 V at 0 percent to greater than 3.5 V at 100 percent.

⇒	If the voltage parameter does not change gradually and smoothly, replace the TC control solenoid.

11. Inspect the turbocharger for debris, damage, or sticking vanes. Refer to Turbocharger Cleaning and Inspection.
12. If all circuits, the TC control solenoid, and the TC vane position sensor tests are normal, replace the turbocharger assembly.

Important: You must perform the Circuit/System Testing in order to verify the integrity of the TC vane position sensor circuits before proceeding with the Component Testing.

TC Vane Position Sensor

1. Ignition OFF, remove the TC vane position sensor.
2. Connect the harness connector to the TC vane position sensor.
3. Ignition ON, slowly depress the button on the end of the TC position sensor while observing the TC Vane Position Sensor parameter on the scan tool for a smooth decreasing percentage from 100-0 percent without any spikes or dropouts.

⇒	If the TC Vane Position Sensor parameter is erratic, replace the TC vane position sensor.

1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Turn OFF the ignition for 90 seconds.
5. Duplicate the Conditions for Running the DTC and use the freeze Frame/Failure Records, if applicable, in order to verify the DTC does not reset. If the DTC resets or another DTC is present, refer to the Diagnostic Trouble Code (DTC) List - Vehicle and perform the appropriate diagnostic procedure.
6. If any service has been performed on the turbocharger or on the turbocharger components, a turbocharger relearn must be performed. Failure to perform the turbocharger learn procedure may cause this DTC to set. Refer to Turbocharger Learn.