Hummer H2. Manual - part 179

closed. The BCM will request the security telltale to remain OFF.

Idle State 

The CTD system will be in the idle state when the ignition switch is in the RUN position and any door is open. 
The BCM will request the security telltale to remain OFF. 

Disarmed State 

The CTD system will be in the disarmed state when the ignition switch is in the LOCK off position and all the 
doors are closed. The BCM will request the security telltale to remain OFF. 

Ready-To-Arm State 

The CTD system will be in the ready-to-arm state when the ignition switch is in the LOCK off position and any 
door opens. The BCM will request the security telltale to flash. 

Arm Initiated State 

The CTD system will be in the arm initiated state when the ignition switch is in the LOCK off position, any 
door opens, and the BCM detects a lock command from either the power door lock switch or the remote control 
door lock receiver. The BCM will request the security telltale to remain ON. 

Arm Delay State 

The CTD system will enter the arm delay state when the ignition switch is in the LOCK off position, the BCM 
receives a LOCK command from either the power door lock switch or the remote control door lock receiver and 
all the doors are closed. The BCM will request the security telltale to remain ON for 15 seconds. 

Armed State 

The CTD system will enter the armed state after the 15 second delay of the arm delay state, unless the BCM 
detects any door opening within that time. The BCM monitors the inputs (listed above) in order to determine 
whether to activate the alarm or to disarm the system. The BCM will request the security telltale to remain OFF.

Alarmed State 

The CTD system will enter the alarmed state from the armed state if any door opens. The horns and the exterior 
lights will alternate off and on for approximately two minutes or until an unlock command is received by the 
BCM. If the BCM does not receive an unlock command, the CTD system will go back to the armed state. The 
BCM will request the security telltale to remain off. The CTD system will change from the alarm state to the off 
state if the vehicle control module (VCM)/powertrain control module (PCM) receives a valid Passlock(tm) 
ignition key rotation. 

Remote Panic Alarm/Vehicle Locator State 

The CTD system will enter the remote panic alarm/vehicle locator state when the panic button on the key fob is 
pressed. When the panic button is pressed, the remote control door lock receiver sends a message to the BCM. 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Theft Deterrent - Hummer H2

  

The BCM will sound the horns and flash the headlamps and the parklamps. You can disable the remote panic 
alarm/vehicle locator state by pressing the panic button on the key fob again or the system will time out after 30 
seconds. 

Locking the Vehicle Without Arming the System 

Use one of the following procedures in order to lock the vehicle without arming the system: 

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Procedure A - Lock the vehicle using the manual door lock knobs. Close all the doors.  

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Procedure B - Close all the doors. Use the key or the power door lock switch in order to lock the door. 
The doors must be closed prior to locking the doors for this procedure.  

Disarming the System 

In the arm initiated mode, the following conditions are true: 

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The security telltale is ON.  

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The doors are open.  

In order to disarm a system in the arm initiated mode, perform one of the following procedures: 

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Press the power door lock switch to the UNLOCK position.  

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Press the door unlock button on the key fob.  

In order to disarm a system in the arm delay or the armed mode, perform one of the following procedures: 

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Use the key in order to unlock one of the doors.  

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Press the door unlock button on the key fob.  

Deactivating the Alarm 

In the alarm mode, the following conditions are true: 

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The horns sound intermittently.  

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The headlights and the parklamps are flashing.  

In order to deactivate a system in the alarm mode, perform one of the following procedures: 

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Use the key in order to unlock one of the doors.  

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Press the door unlock button on the key fob.  

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If the vehicle control module (VCM)/powertrain control module (PCM) receives a valid Passlock(R) 
ignition key rotation.  

Alarm State Activation 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Theft Deterrent - Hummer H2

  

Perform the following steps in order to verify that the system activates the alarm state: 

1. Open a window. Opening the window ensures that you will be able to open the door from the outside 

using the manual door lock knob.  

2. Place the system in the armed state.  

3. Reach through the window and unlock the door using the manual door lock knob.  

4. Open the door.  

The system enters the alarm state. The following actions occur for approximately 2 minutes: 

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The horns sound intermittently.  

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The exterior lamps flash.  

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After 2 minutes and all the doors closed, the system automatically returns back to the armed state.  

Return System to Arm Initiated State 

Perform the following steps in order to verify that the system returns to the armed initiated mode: 

1. Place the system in the armed mode.  

2. Use the key in order to unlock the door.  

3. Open the door.  

4. The system does not enter the alarm mode. The SECURITY telltale flashes. The flashing telltale indicates 

that the system has entered the ready-to-arm state.  

5. Press the power door lock switch to the LOCK position or the key fob LOCK button.  

Ignition Switch Disarm Function 

Perform the following steps in order to verify that the ignition disarm function operates: 

1. Stay in the vehicle.  

2. Place the system in the armed state.  

3. Wait for the SECURITY telltale to turn off. The system is armed when the SECURITY telltale turns off.  

4. Cycle the ignition switch from the LOCK position to the RUN position. Return the ignition switch to the 

LOCK position.  

5. Open any door.  

The system does not enter the alarm mode. The SECURITY telltale flashes. The flashing telltale indicates that 
the system has entered the ready-to-arm state. 

VEHICLE THEFT DETERRENT (VTD) DESCRIPTION AND OPERATION 

Passlock(tm) System 

The theft deterrent system has been incorporated into the body control module (BCM). The theft deterrent is 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Theft Deterrent - Hummer H2

  

provided in order to prevent the vehicle operation if the correct key is not used in order to start the vehicle. The 
ignition key turns the lock cylinder. The cylinder rotation produces an analog voltage code in the Passlock(tm) 
sensor. This voltage code is received by the BCM. The BCM compares the voltage code to the previously 
learned voltage code. If the codes match, a class 2 message is sent from the BCM to the powertrain control 
module (PCM)/vehicle control module (VCM). The message enables the fuel injectors. 

The design of the Passlock(tm) system is to prevent vehicle theft by disabling the engine unless the ignition 
lock cylinder rotates properly by engaging the correct ignition key. The system is similar in concept to the 
PASS-Key(R) system. However, the Passlock(tm) system eliminates the need for a key mounted resistor pellet. 
The components of the Passlock(tm) system are as follows: 

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The ignition lock cylinder  

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The ignition switch  

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The Passlock(tm) sensor  

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The Body control module (BCM)  

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The security telltale  

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The vehicle/powertrain control module (VCM/PCM)  

Ignition Lock Cylinder and Housing 

The ignition lock cylinder is located at the upper right side of the steering column. The Passlock(tm) sensor is in 
the steering column. The Passlock(tm) sensor is separate from the key and lock cylinder. The key and the lock 
cylinder work together in order to determine if the proper ignition key was used to start the vehicle. 

In the event of an open Class 2 serial data line between the BCM and the VCM/PCM, the vehicle will become 
fail-enabled if the VCM/PCM has already received the password from the BCM for that ignition cycle, the 
engine is running. In this event, the following conditions occur: 

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The security telltale will be ON continuously.  

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The VCM/PCM will become fail-enabled for future ignition cycles.  

If a failure in the Class 2 serial data line occurs before the ignition cycle, when the VCM/PCM is not fail-
enabled, the following conditions occur: 

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The VCM/PCM will never receive a valid password in order to enable the fuel injectors.  

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The vehicle will not start.  

Ignition Switch 

The lock cylinder and the visible key insert portion of the ignition switch are located at the upper right side of 
the steering column. The electrical switching portion of the assembly is separate from the key and lock cylinder. 
The electrical switch portion is hidden inside the steering column. The electrical switch portion and the key and 
lock cylinder synchronize and work in conjunction through the action of the mechanical assembly between the 2 
parts. 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Theft Deterrent - Hummer H2