GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 GMC C Sierra - 2WD 🢒 DTC 🢒 DTC P0045

Circuit Description

The position of the turbocharger (TC) vanes is controlled by the engine control module (ECM). The ECM utilizes a TC vane control solenoid valve and a TC vane position sensor to control the TC vanes. When the engine is not under load, the TC vanes are in an open position, or no boost condition. When the engine is under load, the ECM commands the control solenoid valve to close the TC vanes, thus increasing the boost. The ECM will vary the boost dependant upon the load requirements of the engine. The vane control solenoid valve uses 2 circuits, a control circuit and a low reference circuit. The ECM uses a pulse width modulation on the control circuit to open and control the solenoid valve. The ECM provides a ground on the low reference circuit. If the ECM detects any circuit failure, DTC P0045 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0045 Turbocharger Vane Position Control Solenoid Control Circuit

Conditions for Running the DTC

The engine run time is more than 30 seconds.

Conditions for Setting the DTC
    • The control module detects that the commanded state of the driver and the actual state of the control circuit Do Not match.
    • The above condition exists for more than 2 seconds.

Action Taken When the DTC Sets
    • The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

Are DTCs P0652, P0653, P2564, or P2565 also set?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

  1. Start the engine.
  2. Select the TC vane position control solenoid test in Scan Tool Output Controls.
  3. Raise the engine RPM to 1,200 RPM and maintain.
  4. Command the turbocharger (TC) vane position control solenoid valve to ON and back OFF with a scan tool.

Does the engine speed change when the valve is commanded ON?

Go to Step 4

Go to Step 5

4
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Turn ON the ignition, with the engine OFF.
  4. 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.

Did the DTC fail this ignition?

Go to Step 5

Go to Intermittent Conditions

5
  1. Turn OFF the ignition for 30 seconds.
  2. Disconnect the TC vane position control solenoid valve.
  3. Connect a J 34730-405 Injector Test Lamp between the high control circuit of the solenoid valve and the low reference circuit of the solenoid valve.
  4. Turn ON the ignition, with the engine OFF.
  5. Select the TC Vane Pos. Ctrl. Solenoid test in scan tool output controls.
  6. Command the TC Vane Pos. Ctrl. Solenoid to OFF.

Does the test lamp illuminate?

Go to Step 10

Go to Step 6

6

Command the TC Vane Pos. Ctrl. Solenoid to ON with a scan tool.

Does the test lamp illuminate?

Go to Step 8

Go to Step 7

7
  1. Turn OFF the ignition for 30 seconds.
  2. Connect a J 34730-405 between the high control circuit of the solenoid valve and to a good ground.
  3. Turn ON the ignition, with the engine OFF.
  4. Command the TC Vane Pos. Ctrl. solenoid valve to ON with the scan tool.

Does the test lamp illuminate?

Go to Step 11

Go to Step 9

8
  1. Turn OFF the ignition.
  2. Ensure the engine control module (ECM) has powered down.
  3. Connect a J 34730-405 between the low reference circuit of the solenoid valve and to battery voltage with a fused jumper wire.
  4. Ensure that the ignition is OFF.

Does the test lamp illuminate?

Go to Step 12

Go to Step 13

9

Test the control circuit of the solenoid valve for the following conditions:

    • An open
    • A short to ground
    • High resistance
        Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 16

10

Important: Disconnecting the ECM may eliminate the short during testing.

Test the control circuit of the solenoid valve for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 16

11

Test the low reference circuit of the solenoid valve for an open, high resistance, or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 16

12

Test the low reference circuit of the solenoid valve for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 16

13
  1. Disconnect the TC vane position sensor.
  2. Test the signal circuit of the position sensor for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 14

14

Test the control circuit and the low reference circuit of the TC vane position control solenoid valve for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 15

15

Test for an intermittent and for a poor connection at the vane control solenoid valve. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 17

16

Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 19

17
  1. Inspect the TC for debris, damage, or stuck. Refer to Turbocharger Cleaning and Inspection in Engine Mechanical.
  2. If required, replace the TC. Refer to Turbocharger Replacement in Engine Mechanical.

Did you find and correct the condition?

Go to Step 20

Go to Step 18

18

Replace the TC vane control solenoid valve. Refer to Turbocharger Control Solenoid Valve Replacement .

Did you complete the replacement?

Go to Step 20

--

19

Replace the ECM. Refer to Engine Control Module Replacement .

Did you complete the replacement?

Go to Step 20

--

20
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Perform the turbocharger learn procedure. Refer to Turbocharger Learn .
  5. 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.

Did the DTC fail this ignition?

Go to Step 2

Go to Step 21

21

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnostic Trouble Code (DTC) List

System OK