Hummer H1 (2006+). Manual - part 74

OBD-140

On-Board Diagnostics

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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.

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

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” per-
formed?

Go to step 2.

Go to OBD Sys-

tem Check.

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

P0045

P0046

P0652

P2563

P2564

P2565

Are any of these DTCs set?

Go to the Diag-

nostic for each

Trouble Code in

numerical order

Go to Step 3

Observe the Boost Pressure Sensor parameter and the BARO pa-
rameter with a scan tool.

Is the difference between the values more than the specified
value?

3 kPa

Go to Step 12

Go to Step 4

Turn OFF the ignition.

Remove the boost sensor from the intake manifold.

Inspect for the following conditions:

• A plugged sensor port

• A damaged or leaking seal

Did you find and correct the condition?

Go to Step 23

Go to Step 5

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On-Board Diagnostics OBD-141

5745804

Connect the electrical connector to the boost sensor.

Connect a J 23738-A vacuum pump to the sensor port.

Turn ON the ignition, with the engine OFF.

Observe the Boost Pressure Sensor parameter with a scan
tool.

Slowly apply vacuum with the J 23738-A to the sensor until
10 inches Hg is reached.

Does the Boost Pressure Sensor parameter decrease?

Go to Step 6

Go to Step 19

Observe the Boost Pressure Sensor parameter with a scan
tool.

Remove the vacuum from the sensor port.

Does the Boost Pressure Sensor parameter return to the value ob-
served in Step 3?

Go to Step 7

Go to Step 19

Inspect the following components:

• Inspect the air cleaner element for the following condi-

tions:

• Excessive dirt

• Debris

• Water saturation

• Inspect the air intake duct for a leak or restriction.

Did you find and correct the condition?

Go to Step 23

Go to Step 8

Test the charge air cooler and connecting pipes and hoses for air
leaks using the J 46091 Charge Air Cooler Tester.

Did you find and correct the condition?

Go to Step 23

Go to Step 9

Inspect the exhaust system for the following conditions:

• Leaks between the exhaust manifolds and the turbocharger

• Restrictions

• Aftermarket parts

Did you find and correct the condition?

Go to Step 23

Go to Step 10

Remove and inspect the turbocharger for wear or damage.

Did you find a condition with the turbocharger?

Go to Step 22

Go to Step 11

Test for the following conditions:

• Charge air leaks between the following components:

• Air inlet tube

• Intake manifold tube

• Center intake manifold

• Left and right intake manifolds

• Left and right cylinder heads

• Head gasket failure--Refer to Engine Compression Test.

• Worn piston rings--Refer to Engine Compression Test.

Repair as necessary.

Did you find and correct the condition?

Go to Step 23

Intermittent Go

To Diagnostic

Aids

Step

Action

Value(s)

Yes

OBD-142

On-Board Diagnostics

_____________________________________________

Test for an intermittent and for a poor connection at the boost
pressure sensor connector.

Did you find and correct the condition?

Go to Step 23

Go to Step 13

Disconnect the boost pressure sensor.

Measure the amperage between the 5-volt reference circuit
614 (GY) and the low reference circuit 616 (OR/BK), at the
boost pressure sensor connector, with a DVOM.

Is the amperage more than the specified value?

220 mA

Go to Step 14

Go to Step 15

Connect a jumper wire between the 5-volt reference circuit
614 (GY) pin C and the signal circuit 615 pin B of the boost
pressure sensor at the connector.

Observe the Boost Pressure Sensor parameter with the scan
tool.

Is the pressure more than the specified value?

254 kPa

(36 psi)

Go to Step 20

Go to Step 17

Disconnect the engine control module (ECM).

Measure the resistance of the 5-volt reference circuit 614
(GY) between the boost pressure sensor pin C and C75 pin
39 of the ECM, with a DVOM.

Is the resistance more than the specified value?

5 ohms

Go to Step 19

Go to Step 16

Measure the resistance of the low reference circuit 616 (OR/BK)
between the boost pressure sensor pin A and C76 pin 30 of the
ECM, with a DVOM.

Is the resistance more than the specified value?

5 ohms

Go to Step 19

Go to Step 21

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

Did you find and correct the condition?

Go to Step 23

Go to Step 18

Disconnect the ECM.

Measure the resistance of the boost pressure sensor signal
circuit 615 (LG) between the boost pressure sensor pin B and
C76 pin 23 of the ECM with a DVOM.

Is the resistance more than the specified value?

5 ohms

Go to Step 19

Go to Step 21

Repair the high resistance in the circuit.

Did you complete the repair?

Go to Step 23

Replace the faulty boost pressure sensor.

Did you complete the replacement?

Go to Step 23

Replace the faulty ECM.

Did you complete the replacement?

Go to Step 23

Replace the faulty turbocharger.

Did you complete the replacement?

Go to Step 23

Step

Action

Value(s)

Yes

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On-Board Diagnostics OBD-143

5745804

Clear the DTCs with a scan tool.

Turn OFF the ignition for 30 seconds.

Start the engine.

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 15

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

Go to the appli-

cable DTC

table.

System OK.

Step

Action

Value(s)

Yes

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