Hummer H1 (2006+). Manual - part 52

OBD-52

On-Board Diagnostics

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DTC P0045 Turbocharger Boost Control Circuit (Figure OBD-17)

Figure OBD-17:   Turbocharger Boost Control Circuit

Circuit Description

The position of the turbocharger vanes is controlled by the engine control module (ECM). The ECM utilizes a turbocharger vane
control solenoid valve and a turbocharger vane position sensor to control the turbocharger vanes. When the engine is not under
load, the turbocharger 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 turbocharger 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. 

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 diag-

nostic 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 consecu-
tive 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. 

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 On-Board Diagnostics  OBD-53

5745804

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

Value(s)

Yes

No

    1

NOTE: Before clearing DTC(s) use the scan tool “Capture info” to
record Freeze Frame and Failure Records for reference, as data will be
lost when “Clear Info” function is used 

Was the “On-Board Diagnostic (OBD) System Check” performed?

Go to step 2.

Go to OBD 

System

Check.

    2

If any of the following DTCs are set, go to that DTC first.

 P0652

 P0653

 P2564

 P2565 

Are any of these DTCs set?

Go to the 

Diagnostic

for each

Trouble Code

in numerical 

order

Go to Step 3 

    3

1.

Start the engine.

2.

Select the turbocharger (TC) vane position control solenoid test in 
Scan Tool Output Controls.

3.

Raise the engine RPM to 2,000 RPM and maintain.

4.

Command the turbocharger vane position control solenoid valve to 
ON and back OFF with a scan tool.

5.

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

Intermittent, 

go to Diag-

nostic Aids.

    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 con-
trol 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

OBD-54

On-Board Diagnostics

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    7

Turn OFF the ignition for 30 seconds.

2.Connect a J 34730-405 between the high control circuit of the sole-
noid 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

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 sole-
noid 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 condi-
tions:

• An open 

• A short to ground 

• High resistance

Did you find and correct the condition?

Go to Step 20 

Go to Step 16

   10

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

Test the control circuit of the solenoid valve for a short to voltage. 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 re-
sistance, or a short to voltage.

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.

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. 

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 po-
sition control solenoid valve for high resistance.

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 so-
lenoid valve. 

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. 

Did you find and correct the condition?

Go to Step 20

Go to Step 19

   17

1.

Inspect the turbocharger for debris, damage, or stuck.

2.

If required, replace the turbocharger. 

3.

Did you find and correct the condition?

Go to Step 20 

Go to Step 18 

Step

Action

Value(s)

Yes

No

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 On-Board Diagnostics  OBD-55

5745804

   18

Replace the faulty TC vane control solenoid valve. 

Did you complete the replacement?

Go to Step 20 

   19

Replace the faulty ECM. 

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. 

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

1.

Using the Scan Tool select “Capture Info,” Review Info.” Are any 
DTC’s displayed that have not been diagnosed?

Go to the 

applicable

DTC table.

System OK.

Step

Action

Value(s)

Yes

No