Hummer H1 (2006+). Manual — part 51

OBD-48

On-Board Diagnostics

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Figure OBD-15: Fuel Pressure Sensor

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On-Board Diagnostics OBD-49

5745804

DTC P0016 Crank Position (CKP) Camshaft Position (CMP) Correlation (Figure OBD-16)

Figure OBD-16: Crank Position (CKP) Camshaft Position (CMP) Sensors

Circuit Description

The engine control module (ECM) monitors the crankshaft position (CKP) and the camshaft position (CMP) signals to determine if
they are synchronized. If both signals are not observed by the ECM within a narrow time window, the ECM will determine that an
error has occurred and DTC P0016 will set.

Conditions for Setting the DTC

The DTC will set if the following condition is met:

• When the engine is cranking or running, the cam sensor pulses received by the ECM does not equal 3 in one crankshaft rev-

olution.

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

OBD-50

On-Board Diagnostics

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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.

Diagnostic Aids

Inspect for the following items:

• A loose CMP sensor causing a variance in the sensor signal

• Excessive free play or damage of the timing gears

• The Camshaft Reference Signal Missed parameter will only increment for an intermittent. A constant failure of the CMP

sensor will not cause the parameter to increment, but will set DTC P0340.

Step

Action

Value(s)

Yes

No

1

1.

Perform the OBD Self-Test.

2.

Did you perform the OBD Self-Test?

Go to step 2.

Go to OBD

System

check.

2

1.

Observe the Freeze Frame/Failure Records data 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 3

Go to Inter-

mittent Con-

ditions

3

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

• DTC P0335

• DTC P0336

• DTC P0340

• DTC P0341

• DTC P0699

Are any of these DTCs set?

Go to the

Diagnostic

for each

Trouble Code

in numerical

order

Go to Step 4

4

1.

Turn OFF the ignition.

2.

Disconnect the camshaft position (CMP) Sensor.

3.

Test all of the circuits going to the CMP sensor for high resistance.

Did you find and correct the condition?

Go to Step 10

Go to Step 5

5

Inspect for a loose CMP sensor. If the sensor is loose and cannot be
tightened, the sensor must be replaced.

Does the CMP sensor move without being able to be tightened?

Go to Step 8

Go to Step 6

6

1.

Remove the CMP sensor.

2.

Inspect for a broken CMP sensor casing or a rattle inside when
shaken.

Does the CMP sensor show any signs of physical damage?

Go to Step 8

Go to Step 7

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On-Board Diagnostics OBD-51

5745804

7

1.

Remove the front engine cover.

2.

Check for excessive camshaft end-play.

3.

Inspect for front engine cover damage.

4.

Inspect for timing gear misalignment or damage.

5.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

1.

Replace the faulty CMP sensor.

2.

Is the repair complete?

Go to Step 10

9

1.

Replace the faulty ECM.

2.

Is the repair complete?

Go to Step 10

10

1.

Using the scan tool, select “DTC,” “Clear info.”

2.

Start the engine and idle at normal engine operating temperature.

3.

Select “DTC,” “Specific,” then enter the DTC number which was
set.

4.

Operate the vehicle within the condition for setting this DTC. Does
the scan tool indicate that this diagnostic Ran and Passed?

Go to step 11.

Go to step 2.

11

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