Hummer H2. Manual — part 1433

Fig. 34: TAC Module Electrical Connectors
Courtesy of GENERAL MOTORS CORP.

1. Connect the TAC module electrical connectors to the TAC module.

2. Install the TAC module onto the studs and install the mounting nuts.

Tighten: Tighten the TAC mounting nuts to 9 N.m (80 lb in).

3. Install the left hand corner brace.

Tighten: Tighten the corner brace bolts to 25 N.m (18 lb ft).

NOTE:

Refer to Fastener Notice in Cautions and Notices.

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls (Introduction) - 4.8L, 5.3L, and 6.0L - Hummer H2

CKP SYSTEM VARIATION LEARN PROCEDURE

1. Install a scan tool.

2. Monitor the powertrain control module (PCM) for DTCs with a scan tool. If other DTCs are set, except

DTC P0315, refer to Diagnostic Trouble Code (DTC) List for the applicable DTC that set.

3. Select the crankshaft position (CKP) variation learn procedure with a scan tool.

4. The scan tool instructs you to perform the following:

1. Accelerate to wide open throttle (WOT).

2. Release throttle when fuel cut-off occurs.

3. Observe fuel cut-off for applicable engine.

4. Engine should not accelerate beyond calibrated RPM value.

5. Release throttle immediately if value is exceeded.

6. Block drive wheels.

7. Set parking brake.

8. DO NOT apply brake pedal.

9. Cycle ignition from OFF to ON.

10. Apply and hold brake pedal.

11. Start and idle engine.

12. Turn A/C OFF.

13. Vehicle must remain in Park or Neutral.

14. The scan tool monitors certain component signals to determine if all the conditions are met to

continue with the procedure. The scan tool only displays the condition that inhibits the procedure.
The scan tool monitors the following components:

z

CKP sensors activity-If there is a CKP sensor condition, refer to the applicable DTC that set.

z

Camshaft position (CMP) sensor activity-If there is a CMP sensor condition, refer to the
applicable DTC that set.

z

Engine coolant temperature (ECT)-If the ECT is not warm enough, idle the engine until the
engine coolant temperature reaches the correct temperature.

5. Enable the CKP system variation learn procedure with a scan tool.

6. Accelerate to WOT.

7. Release when the fuel cut-off occurs.

8. The scan tool displays Test In Progress.

9. The scan tool displays Learn Status: Learned this ignition. If the scan tool indicates that DTC P0315 ran

and passed, the CKP variation learn procedure is complete. If the scan tool indicates DTC P0315 failed or

IMPORTANT: While the learn procedure is in progress, release the throttle immediately

when the engine starts to decelerate. The engine control is returned to the
operator and the engine responds to throttle position after the learn
procedure is complete.

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls (Introduction) - 4.8L, 5.3L, and 6.0L - Hummer H2

did not run, refer to DTC P0315 . If any other DTCs set, refer to Diagnostic Trouble Code (DTC) List
for the applicable DTC that set.

10. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.

11. The CKP system variation learn procedure is also required when the following service procedures have

been performed, regardless of whether DTC P0315 is set:

z

A CKP sensor replacement

z

An engine replacement

z

A PCM replacement

z

A harmonic balancer replacement

z

A crankshaft replacement

z

Any engine repairs which disturb the CKP sensor relationship

ENGINE COOLANT TEMPERATURE (ECT) SENSOR REPLACEMENT

Removal Procedure

1. Turn OFF the ignition.

NOTE:

Use care when handling the coolant sensor. Damage to the coolant sensor
will affect the operation of the fuel control system.

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls (Introduction) - 4.8L, 5.3L, and 6.0L - Hummer H2

Fig. 35: ECT Sensor Electrical Connector
Courtesy of GENERAL MOTORS CORP.

2. Drain the cooling system below the level of the ECT sensor. Refer to Draining and Filling Cooling

System in Engine Cooling.

3. Disconnect the electrical connector from the engine coolant temperature (ECT) sensor.

2004 Hummer H2

2004 ENGINE PERFORMANCE Engine Controls (Introduction) - 4.8L, 5.3L, and 6.0L - Hummer H2