Content .. 553 554 555 556 ..

Hummer H2. Manual - part 555

voltage to the power window motor through the power window motor down circuit. Since the opposite side of
the motor is connected to the normally closed contacts of the up relay to ground through the power window
motor up circuit, the window moves down. If a rear power window switch is placed in the up position, the up
relay would energize and allow battery voltage to the power window motor through the power window motor
up circuit. Since the opposite side of the motor is connected to the normally closed contacts of the down relay to
ground through the power window motor down circuit, the window moves up.

The rear passenger power windows can also be controlled from the power window master switch. The power
window master switches for the rear passenger power windows have two positions UP and Down and its
position is a direct input into the DDM. Upon receiving a request for rear passenger power window operation
(switch activation), the DDM transmits a Class 2 message indicating the changed switch position. When the
BCM receives this message, the BCM can control the rear window up and down relays.

Express Down Operation

The express down function controls both the driver and front passenger power windows but only from the
driver door power window master switch. When either the driver or front passenger window switch is
momentarily depressed to the express down position, it is a direct input into the DDM. If the request was for the
driver power window, the DDM supplies voltage to the power window down circuit continuously until the
power window reaches the bottom of its travel. At this point, the DDM senses an over current situation on the
power window down circuit and interrupts the voltage supply. If the request was for the front passenger power
window, the DDM transmits a Class 2 message indicating an express down function was requested. When the
PDM receives this message, the PDM supplies voltage to the power window down circuit continuously until the
power window reaches the bottom of its travel. At this point, the PDM senses an over current situation on the
power window down circuit and interrupts the voltage supply.

Power Window Lockout Operation

The DDM contains a window lockout switch that is responsible for the disabling of all the passenger windows
from the individual passenger window switches. When the window lockout switch is activated, the DDM
transmits a Class 2 message indicating that a window lockout request has been received. When the PDM
receives this message, it will disable the power window motor up and down circuits. When the BCM receives
this message, it will interrupt the up and down relay coil feed voltage for both rear doors. Once activated, the
lockout feature will remain in effect until the ignition switch is cycled or the DDM receives another power
window lockout switch activation.

POWER DOOR LOCKS DESCRIPTION AND OPERATION

Door Lock System Components

The power door lock system consists of the following components:

The driver door module (DDM)

The passenger door module (PDM)

The body control module (BCM)

The driver information center (DIC)

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Doors - Hummer H2

The rear door lock switch

The door lock relay

The door unlock relay

The liftgate lock relay-utility vehicles with liftgate only

The reversible door lock actuators in each of the doors and liftgate

LOCKS 20A fuse (rear lock/unlock relay supply voltage)

ECC 10A fuse (liftgate lock relay supply voltage)

Door Lock System Controls

The power door lock system can be controlled by any of the following:

A power door lock or unlock switch activation

A keyless entry transmission

An automatic door lock function

A delay lock function

Door lock cylinder switch activation

Lockout Prevention

An airbag deployment

Driver, Passenger and Cargo Door Lock System Operation

The front power door lock switches are integral components of the driver door module (DDM) and passenger
door module (PDM). The switches are two position normally open rocker switches. When placed in either the
lock or unlock positions, the switches provide a direct input to the DDM or PDM. The DDM or PDM monitors
these inputs and sends a Class 2 message indicating a change in the switch's respective position. Modules which
activate the power door lock motors receive the Class 2 message and activate the motor in the appropriate
direction to lock or unlock the vehicle's doors and liftgate. The rear door lock switch provides a lock and unlock
signal to the body control module (BCM). The BCM upon receipt of a lock or unlock signal will control the rear
door lock relays and also send a Class 2 message to the DDM and PDM to perform the appropriate function.

The modules which activate the power lock motors are:

The DDM (driver door lock actuator).

The PDM (passenger front door lock actuator).

The BCM (both rear door lock actuators and cargo door/liftgate).

The DDM and PDM are directly connected to the respective door lock actuator through the door lock motor
lock and unlock circuits. Once a door lock or unlock request has been received, the module will supply battery
voltage to one side of the actuator and ground the other causing the doors to lock or unlock.

The rear passenger and cargo doors differ slightly in that they use lock and unlock relays. The relays supply and
coil sides receive a constant voltage through the battery voltage supply circuit. The normally closed contacts are

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Doors - Hummer H2

connected to ground and the control side is connected to the BCM. Once a door lock or unlock request has been
received by the BCM, the BCM will ground the control side of the appropriate relay. This energizes the relay
and allows voltage to be applied to either the door lock motor lock or unlock circuits. since the other side of the
door lock actuator is connected to the normally closed contacts of the opposing relay to ground, the doors lock
or unlock.

Liftgate Locking Operation

The liftgate will lock any time the vehicle is shifted out of park on vehicles equipped with an automatic
transmission and at vehicle speeds exceeding 5 kph with manual transmission. This happens in conjunction with
auto door locks if enabled or independently of auto door locks if the feature is disabled. This ensures that the
liftgate is locked anytime the vehicle is shifted out of park or when the vehicle is in motion.

The liftgate lock relay supply and coil sides receive a constant voltage through the battery voltage supply circuit
and the ECC fuse. The normally closed contact is connected to ground and the control side is connected to the
body control module (BCM). A lock function will occur when a door lock switch activation, keyless entry lock
transmission, auto door lock function or a liftgate lock function has been received by the BCM. The BCM will
then ground the control side of the liftgate lock relay. This energizes the relay and allows voltage to be applied
to the liftgate lock actuator lock control circuit. Since the other side of the liftgate lock actuator is connected to
the normally closed contacts of the door unlock relay to ground, the liftgate will lock. When an unlock function
occurs the BCM will ground the control side of the unlock relay and the rear doors and liftgate will unlock.

The BCM also runs diagnostics on the liftgate lock relay control circuit and will set DTC B3825 as current and
also send a Class 2 message to the DIC. The DIC will display REPLACE LIFTGATE FUSE to inform the
driver that a fault has been detected in the liftgate lock circuit and that the liftgate is not locked. Faults that will
set the DTC and cause the DIC to display the message could be any of the following:

An open ECC fuse

An open or short to ground in the liftgate lock relay battery positive voltage circuit

A faulty liftgate lock relay

An open or short to ground in the liftgate lock relay control circuit

A short to ground in the liftgate lock actuator lock control circuit

A faulty BCM

Programmable Automatic Door Locks

The automatic door lock feature can be programmed to control the door lock system. The automatic door lock
feature is factory programmed to have all doors lock and unlock. For detailed instructions on programming the
automatic door locks, refer to Vehicle Personalization in Personalization.

When the automatic door lock feature is programmed to control the door lock system, the driver door module
(DDM), passenger door module (PDM) and body control module (BCM) will lock the vehicle doors if the
following inputs are true:

Ignition 1 input is active.

All door jamb switch inputs are inactive.

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Doors - Hummer H2

Cargo door or liftgate/liftglass ajar inputs are inactive.

Transmission is shifted out of park.

This automatic door lock function will only occur once per ignition cycle unless, a door jamb switch input
changes state to active and back to inactive. Then the DDM, PDM and BCM will lock all doors again.

Once the automatic door lock feature has locked the doors, the BCM will then unlock all the doors when the
transmission is shifted into park.

Lockout Prevention

This feature prevents the locking of the driver door if the ignition key is left in the ignition lock cylinder. If a
lock function occurs from any door lock switch and the body control module (BCM) senses an active state on
either the left front door latch signal, secondary door latch switch signal and/or the liftgate ajar switch signal
circuits and the key in ignition switch signal circuit is in the YES state, the BCM, driver door module (DDM)
and passenger door module (PDM) will lock the doors and then the DDM will unlock the driver door.

Delayed Locking Operation

With any door open and a door lock switch is activated in the lock position, the driver door module (DDM),
passenger door module (PDM) and the body control module (BCM) will go into a lock pending state. The BCM
will also give three audible chimes. When the door is closed, the DDM, PDM and the BCM will lock the doors
after approximately five seconds. This feature can be overridden by activating the door lock switch a second
time and the doors will lock even with a door open.

Unlock After Air Bag Deployment

This feature will unlock all of the vehicle doors 15 seconds after an air bag deployment.

DOOR AJAR INDICATOR DESCRIPTION AND OPERATION

Door Ajar Indicator System Components

The door ajar indicator system consists of the following components:

The driver door module (DDM)

The passenger front door module (PDM)

The body control module (BCM)

The instrument panel cluster (IPC)

The driver information center (DIC)

The driver door ajar switch

The passenger door ajar switch

The left rear door ajar switch

The right rear door ajar switch

2004 Hummer H2

2004 ACCESSORIES & EQUIPMENT Doors - Hummer H2

Content .. 553 554 555 556 ..