Hummer H1 (2006+). Manual — part 153

OBD-456

On-Board Diagnostics

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DTC P2564 Turbocharger Boost Control Position Sensor Circuit Low Voltage (Figure OBD-117)

Figure OBD-117: Turbocharger Boost Control Position Sensor 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 position sensor uses the following three circuits:

• A 5-volt reference circuit

• A low reference circuit

• A signal circuit

The ECM provides the sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Movement of
the sensor from the closed position to the open position provides the ECM with a signal voltage through the position sensor signal
circuit. If the ECM detects an excessively low position sensor signal voltage, DTC P2564 will set.

Conditions for Setting the DTC

• The turbocharger vane position sensor voltage is less than 1 volt.

• The above condition exists for more than 6 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-

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On-Board Diagnostics OBD-457

5745804

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.

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

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnos-

tic System

Check - Vehicle

2

1.

Turn ON the ignition, with the engine OFF.

2.

Monitor the DTC Information with a scan tool.

Is DTC P0652 also set?

Go to DTC

P0652

Go to Step 3

3

1.

Start the engine.

2.

Select the TC Vane Position Sensor test in Scan Tool Output
Controls.

3.

With the engine at idle, observe the turbocharger (TC) vane
position and the desired TC vane position while command-
ing the TC vane position sensor to 100 percent with the scan
tool.

Is the TC vane position at or near the desired TC vane position
while commanding the TC vane position sensor from 0-100 per-
cent?

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.

Start the engine.

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 Intermit-

tent Conditions

5

1.

Turn OFF the ignition.

2.

.Disconnect the turbocharger vane position sensor.

3.

Turn ON the ignition, with the engine OFF.

4.

Measure the voltage from the 5-volt reference circuit 367
(GY) to a good ground with a DVOM.

Is the voltage less than the specified value?

4.8 Volts

Go to Step 7

Go to Step 6

6

Measure the voltage from the signal circuit 368 (WH) to a good
ground with a DVOM.

Is the voltage less than the specified value?

4.8 Volts

Go to Step 8

Go to Step 9

OBD-458

On-Board Diagnostics

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7

1.

Turn OFF the ignition.

2.

Disconnect C75 (ECM).

3.

Test the vane position sensor 5-volt reference circuit 367
(GY) for an open and for a high resistance between C75 pin
23 and pin C of the vane position sensor connector.

Did you find and correct the condition?

Go to Step 13

Go to Step 10

8

1.

Turn OFF the ignition.

2.

Disconnect C76 (ECM).

3.

Test the vane position sensor signal circuit 368 (WH) for a
short to ground.

Did you find and correct the condition?

Go to Step 13

Go to Step 10

9

Test for an intermittent and for a poor connection at the vane po-
sition sensor.

Did you find and correct the condition?

Go to Step 13

Go to Step 11

10

Test for an intermittent and for a poor connection at the ECM.

Did you find and correct the condition?

Go to Step 13

Go to Step 12

11

Replace the turbocharger vane position sensor.

Did you complete the replacement?

Go to Step 13

12

Replace the faulty ECM.

Did you complete the replacement?

Go to Step 13

13

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 14

14

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

Go to Diagnos-

tic Trouble

Code

System OK

Step

Action

Value(s)

Yes

No

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On-Board Diagnostics OBD-459

5745804

DTC P2565 Turbocharger Boost Control Position Sensor Circuit High Voltage (Figure OBD-
118)

Figure OBD-118: Turbocharger Boost Control Position Sensor 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 position sensor uses the following 3 circuits:

• A 5-volt reference circuit

• A low reference circuit

• A signal circuit

The ECM provides the sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Movement of
the sensor from the closed position to the open position provides the ECM with a signal voltage through the position sensor signal
circuit. If the ECM detects an excessively high position sensor signal voltage, DTC P2565 will set.

Conditions for Setting the DTC

• The ECM detects that the turbocharger vane position sensor signal voltage is more than 3.9 volts.

• The above condition exists for more than 6 seconds.