Hummer H2. Manual — part 2142

Circuit Description

If the vehicle is equipped with a floor mounted console gearshift, an ignition lock cylinder control actuator
system is used in the steering column. The purpose of the system is to prevent the ignition lock cylinder from
being turned to the lock position while the transmission is in gear, this also prevents the steering wheel from
being locked. The system consists of an ignition lock cylinder actuator and a park position switch. The actuator
contains a pin that is spring loaded out, to prevent the ignition lock cylinder from being turned to the lock
position when the gearshift is not in Park. The park position switch is located in the floor mounted gearshift
assembly, as part of the automatic transmission shift lock control switch. The switch is closed with the gearshift
in PARK, and open in all other positions

System Operation

When the gearshift is in the PARK position, the park position switch is closed. This applies voltage to the
ignition lock cylinder actuator and the pin retracts, allowing the ignition lock cylinder to be turned to the LOCK
position. When the gearshift is not in PARK, the park position switch is open. No voltage is applied to the
ignition lock cylinder actuator and the spring loaded pin remains in the out position, preventing the ignition lock
cylinder from being turned to LOCK. If vehicle power is lost while the ignition lock cylinder is not in the
LOCK position, the system will prevent the operator from turning the ignition key to the lock position or
removing the key. If the vehicle has lost power, pushing the ignition lock cylinder release button on the
underside of the ignition lock cylinder will override the system and allow the key to be removed.

Ignition Can/Cannot Be Turned Off with Transmission in Any Gear

Step

Action

Yes

No

Schematic Reference:Column/Ignition Lock Schematics
Connector End View Reference:Steering Wheel and Column Connector End Views

1

Verify the fault is present.
Does the system operate normally?

Go to Testing for

Intermittent

Conditions and Poor

Connections in Wiring

Systems

Go to Step 2

2

Does the automatic transaxle shift lever
operate normally?

Go to Step 3

Go to Diagnostic Starting

Point - Automatic

Transmission Shift Lock

Control in Shift Lock

Control

3

1. Push the ignition lock cylinder control

actuator release button which is on the
underside of the ignition lock
cylinder.

2. Turn the key to the LOCK position

and remove the key.

Were you able to turn the key to the LOCK
position and remove the key?

Go to Step 4

Go to Lock System Does

Not Lock

1. Turn OFF the ignition.

2004 Hummer H2

2004 STEERING Steering Wheel and Column - Hummer H2

4

2. Disconnect the ignition lock cylinder

control actuator.

3. Connect a test lamp between the

battery positive voltage and ground
circuits of the ignition lock cylinder
control actuator.

4. Turn ON the ignition, with the engine

OFF.

5. Cycle the gear shift from Park to

Drive.

Does the test lamp turn ON and OFF with
each cycle?

Go to Step 11

Go to Step 5

5

Does the test lamp remain illuminated with
each cycle?

Go to Step 8

Go to Step 6

6

Connect a test lamp between the ground
circuit of the ignition lock cylinder control
actuator and B+ voltage.
Does the test lamp illuminate?

Go to Step 7

Go to Step 9

7

Test the control circuit of the ignition lock
cylinder control actuator for an open. Refer
to Circuit Testing and to Wiring Repairs
in Wiring Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 10

8

Test the control circuit of the ignition lock
cylinder control actuator for a short to
voltage. Refer to Circuit Testing and to
Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 10

9

Repair the open in the ground circuit of the
ignition lock cylinder control actuator. Refer
to Wiring Repairs in Wiring Systems.
Did you complete the repair?

Go to Step 14

-

10

Inspect for poor connections at the
automatic transmission shift lock actuator.
Refer to Testing for Intermittent
Conditions and Poor Connections and
Connector Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 12

11

Inspect for poor connections at the ignition
lock cylinder control actuator. Refer to
Testing for Intermittent Conditions and
Poor Connections and to Connector
Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 14

Go to Step 13

2004 Hummer H2

2004 STEERING Steering Wheel and Column - Hummer H2

LOCK SYSTEM DOES NOT UNLOCK

Lock System Does Not Unlock

12

Replace the automatic transmission shift
lock actuator. Refer to Automatic
Transmission Shift Lock Actuator
Replacement in Shift Lock Control.
Did you complete the replacement?

Go to Step 14

-

13

Replace the ignition lock cylinder control
actuator. Refer to Steering Wheel Theft
Deterrent Lock Replacement .
Did you complete the replacement?

Go to Step 14

-

14

Operate the system in order to verify the
repair.
Did you correct the condition?

System OK

Go to Step 2

Step

Action

Yes

No

DEFINITION: The lock system does not allow the key to rotate out of the OFF position.

1

Did you review the Steering Wheel and Column
Description and Operation?

Go to

Step 2

Go to Steering Wheel and

Column Description and

Operation

2

Verify that the lock system does not unlock.
Does the lock system operate normally?

System

OK

Go to Step 3

3

Inspect for an incorrect, worn, or damaged key.
Is the key incorrect, worn, or damaged?

Go to

Step 7

Go to Step 4

4

Inspect for a faulty lock cylinder.
Is the lock cylinder damaged?

Go to

Step 8

Go to Step 5

5

Inspect the ignition lock cylinder case assembly for
looseness.
Is the ignition lock cylinder case assembly loose?

Go to

Step 9

Go to Step 6

6

Inspect the ignition switch assembly for damage.
Is the ignition switch assembly damaged?

Go to

Step 10

Go to Step 3

7

Replace the key. Refer to Key and Lock Cylinder
Coding in General Information.
Did you complete the repair?

Go to

Step 11

-

8

Replace the lock cylinder. Refer to Ignition Lock
Cylinder Replacement .
Did you complete the repair?

Go to

Step 11

-

9

Tighten the ignition lock cylinder case assembly.
Refer to Fastener Tightening Specifications .
Did you complete the repair?

Go to

Step 11

-

10

Replace the ignition switch. Refer to Ignition
Switch Replacement .
Did you complete the repair?

Go to

Step 11

-

2004 Hummer H2

2004 STEERING Steering Wheel and Column - Hummer H2

LOCK SYSTEM DOES NOT LOCK

Lock System Does Not Lock

LOCK SYSTEM STICKS IN START

Lock System Sticks in Start

11

Operate the system in order to verify the repair.
Did you correct the condition?

System

OK

Go to Step 3

Step

Action

Yes

No

DEFINITION: The lock system will not allow the key to be turned to the OFF lock position.

1

Did you review the Steering Wheel and Column
Description and Operation?

Go to

Step 2

Go to Steering Wheel and

Column Description and

Operation

2

Verify that the lock system does not lock.
Does the lock system operate normally?

System

OK

Go to Step 3

3

Inspect for a faulty lock cylinder or release button.
Is the lock cylinder or release button damaged?

Go to

Step 6

Go to Step 4

4

Inspect the shift cable adjustment.
Is the shift cable adjusted incorrectly?

Go to

Step 7

Go to Step 5

5

Inspect the ignition switch for damage.
Is the ignition switch damaged?

Go to

Step 8

Go to Step 6

6

Replace the lock cylinder. Refer to Ignition Lock
Cylinder Replacement .
Did you complete the repair?

Go to

Step 9

-

7

Adjust the shift cable. Refer to Automatic Transmission
Range Selector Cable Adjustment in Automatic
Transmission - 4L60-E/4L65-E.
Did you complete the repair?

Go to

Step 9

-

8

Replace the ignition switch. Refer to Ignition Switch
Replacement .
Did you complete the repair?

Go to

Step 9

-

9

Operate the system in order to verify the repair.
Did you correct the condition?

System

OK

Go to Step 3

Step

Action

Yes

No

1

Did you review the Steering Wheel and Column
Description and Operation?

Go to

Step 2

Go to Steering Wheel and

Column Description and

Operation

2

Verify that the lock system sticks in the START
position.
Does the lock system operate normally?

System

OK

Go to Step 3

3

Inspect the ignition lock cylinder case assembly for
damage.

Go to

2004 Hummer H2

2004 STEERING Steering Wheel and Column - Hummer H2