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 learn value, it will default to a stored calibrated value. The ECM will use this value until the enable criteria have been met. The ECM performs the self learn by commanding the TC vanes to 0 percent, then to 100 percent, while monitoring the TC vane position sensor.

The position of the TC vanes are controlled by the ECM. The ECM utilizes a TC vane control solenoid valve (TC control solenoid) and a TC vane position sensor to control the TC vanes. The ECM will vary the boost dependant upon the load requirements of the engine. The vane control solenoid valve has 2 circuits, a high voltage control circuit and a low control circuit. The ECM uses a pulse width modulation (PWM) on the high control and low control circuits to control the solenoid valve. If the commanded vane position did not match the actual vane position by a calibrated threshold. The ECM will detect if the automatic TC learn has failed.

The ECM did not detect a valid learn within 45 seconds.

DTC P003A is a Type B DTC.

DTC P003A is a Type B DTC.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Special Tools

J 34730-405 Injector Test Lamp

1. If DTC P0652, P0653, P0698, P0699, P2564, or P2565 are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
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 95-97 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. Engine running, observe the DTC information with a scan tool. DTC P003A should not set.
6. Operate the vehicle within the Conditions for Running the DTC. 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, allow sufficient time for the ECM to power down.
2. Disconnect the harness connector at the TC control solenoid.
3. Connect the J 34730-405 between the high control and the low control circuits.
4. Ignition ON, command the TC Vane Pos. Ctrl. solenoid ON and OFF with a scan tool. The test lamp should change from Bright to Dim when changing between the commanded states.

⇒	If the test lamp does NOT change brightness, test the low control circuit for a short to voltage. If the circuit tests normal, test the low control and high control circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the ECM.

5. Engine running, observe the TC Vane Pos. Ctrl. Solenoid Amperage parameter for a value of 0.45-1.1 amps.

⇒	If the value is less than 0.4 amp, test the high control circuit for a short to voltage.

6. Ignition OFF, disconnect the harness connectors at the ECM, TC vane position sensor, and the TC control solenoid.
7. Test for less than 5 ohms of resistance on all circuits between the following terminals:

•	The ECM C1 solenoid high control circuit terminal 48 to TC control solenoid terminal A

•	The ECM C1 solenoid low control circuit terminal 96 to TC control solenoid terminal B

•	The ECM C1 sensor signal circuit terminal 20 to TC sensor terminal B

•	The ECM C1 sensor low reference terminal 63 to TC sensor terminal C

•	The ECM C1 sensor 5-volt reference terminal 13 to TC sensor terminal D

⇒	If the resistance is over 5 ohms, 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 the TC vane position sensor.
10. Remove the TC control solenoid from the turbocharger. Connect the ECM and the turbocharger solenoid connectors.
11. Ignition ON, depress the button at the tip of the solenoid slightly. Command the TC Vane Pos. Ctrl. Solenoid ON while observing for the spool valve to open at the slot closest to the button.

⇒	If the spool valve did not operate, replace the TC control solenoid.

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

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

TC Control Solenoid

1. Ignition OFF, disconnect the wire harness at the TC solenoid. Test for a resistance of less than 7 ohms across the TC solenoid.

⇒	If the resistance is more than 7 ohms, replace the TC solenoid.

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

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

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 vane sensor. Observe the TC vane position sensor parameter for a smooth decreasing percentage from 100-0 percent without any spikes or dropouts.

⇒	If the TC Vane Position Sensor parameter does not increment smoothly, replace the TC vane position sensor.

1. Engine running, observe the scan tool TC Vane Position Sensor and the Desired TC Vane Position parameters. Slowly increase the engine speed to 2,500 RPM, and slowly return the engine speed to an idle. The TC Vane Position parameter should remain near or equal to the Desired TC Vane Position parameter.
2. Engine running, observe the scan tool TC Vane Position Sensor parameter while increasing the engine speed to 1,500 RPM and maintaining. Command the TC Vane Pos. Ctrl. Solenoid ON and OFF. The TC Vane Position Sensor parameter should increase to 95-97 percent when the TC solenoid is commanded ON, and decrease to near 0 percent when commanded OFF.
3. Engine running, observe the scan tool TC Vane Position Sensor and the Desired TC Vane Position parameters while increasing the TC vane position sensor in 5 percent increments from 0-100 percent. The TC Vane Position Sensor and the Desired TC Vane Position parameters should remain within 2 percent of each other during the entire range.