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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P003A

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P003A: Turbocharger Boost Control Position Not Learned

Diagnostic Fault Information

Circuit

Short to Ground

Open

Short to Voltage

TC Vane Position Sensor 5-Volt Reference Circuit

P0652

P2564

--

TC Vane Position Sensor Signal Circuit

P2564

P2564

P2565

TC Vane Position Sensor Ground Circuit

--

P2565

--

Turbocharger Boost Control Solenoid Control Circuit

P0045

P0045

P0045

Circuit/System Description

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 performs the self learn by commanding the TC vanes to 0 percent, then to 100 percent, while monitoring the TC vane position sensor.

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

Conditions for Running the DTC
    • DTCs P0047, P0048, P0652, P0653, P2564 and P2565 are not set.
    • The battery voltage is between 10-16 volts.
    • The ignition is ON for longer than 2 seconds.
    • The vane position learning is complete. The vane position learning condition is as follows:
       - The engine is in idle mode.
       - The engine speed is between 500-700 RPM.
       - The vehicle speed is less than 16 km/h (10 mph).
       - The engine coolant temperature (ECT) is between 60-100°C (140-212°F).
       - The fuel temperature is between 0-300°C (32-572°F).
       - The barometric pressure (BARO) is less than 50 kPa.
       - The oil pressure is more than 100 kPa.
       - The above conditions are met for 10 seconds.

Conditions for Setting the DTC

Open Side Condition

    • The vane position sensor signal voltage is less than 0.5 volts.
        OR
    • The vane position sensor signal voltage is more than 2.8 volts.

Closed Side Condition

    • The vane position sensor signal voltage is less than 3.1 volts.
        OR
    • The vane position sensor signal voltage is more than 4.8 volts.

Action Taken When the DTC Sets

DTC P003A is a Type A DTC.

Conditions for Clearing the DTC

DTC P003A is a Type A DTC.

Diagnostic Aids
    • Inspect for any recent engine mechanical repairs. An incorrectly installed turbocharger or turbocharger boost control solenoid will cause this DTC to set.
    • 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 other DTCs to set.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Important: If DTCs P0047, P0048, P0652, P0653, P2564 and P2565 are set, test and repair those DTCs first.

    • Engine at idle, increase the TC vane position sensor in 5 percent increments, from 0-100 percent with a scan tool while observing the TC Vane Position Sensor and the Desired TC Vane Position parameters. The parameters should remain within 2 percent of each other during the entire range.
    • Verify the integrity of the engine exhaust system by inspecting for the following conditions:
       - Damaged components
       - Loose or improper installation

Circuit/System Testing
  1. With the engine at idle, observe the TC Vane Pos. Ctrl. Solenoid Amperage parameter for a value of 0.7 amps.
    2. ⇒If the value is less than 0.3, test the high control circuit for a short to voltage, a short to ground, or an open circuit.
  2. Ignition OFF, disconnect the harness connector at the VNT solenoid.
  3. Ignition ON, verify that a test lamp illuminates between the power supply circuit terminal 1 and ground.
    4. ⇒ If the test lamp does not illuminate, test the power supply circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, disconnect the harness connector at the ECM.
  5. Install a 3-amp fused jumper wire between the power supply circuit terminal 1 and the control circuit.
  6. Ignition ON, verify that a test lamp illuminates between the control circuit at the ECM terminal 2 and ground.
    7. ⇒If the test lamp does not illuminate, test the power supply circuit for a short to ground or an open/high resistance.
  7. Ignition ON, slowly depress the button on the end of the TC sensor. Observe the TC vane position sensor parameter for a smooth decreasing percentage from 100-0 percent.
    8. ⇒If the parameter does not increment smoothly, replace the turbocharger vane position sensor.
  8. Inspect the turbocharger for debris, damage, or sticky vanes.
    9. ⇒If all circuits, the TC solenoid, and the TC vane position sensor tests OK, replace the turbocharger.

Component Testing
    • With the turbocharger solenoid disconnected, measure for a resistance between 3.4-4.1 ohms across the turbocharger solenoid terminals.
       ⇒If the resistance is more than 4.1 ohms or less than 3.4 ohms, replace the solenoid or repair the circuit.
    • With the ignition OFF, remove the turbocharger vane position sensor. With the ignition ON, slowly depress the button on the end of the TC sensor.
    • Observe the TC vane position sensor parameter for a smooth decreasing percentage from 100-0  percent.
       ⇒If the parameter does not increment smoothly, replace the turbocharger vane position sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Turbocharger Replacement
    •  Turbocharger Vane Position Sensor Replacement