Power Windows System Components
The following components are used to control the power windows:
• | Driver door module (DDM) |
• | Front passenger door module (PDM) |
• | LH rear door module (LRDM) |
• | RH rear door module (RRDM) |
• | Driver door switch assembly (DDSA) |
• | RH front power window switch |
• | LH rear power window switch |
• | RH rear power window switch |
• | LH front power window motor |
• | RH front power window motor |
• | LH rear power window motor |
• | RH rear power window motor |
• | Class 2 serial data circuit |
• | PWR WDO 30-amp circuit breaker |
• | DRVR MDL 10-amp fuse -- DDSA and DDM logic, DDM internal driver operation. |
• | PASS MDL 10-amp fuse -- PDM logic and internal driver operation. |
• | RRDR MDL 10-amp fuse -- LRDM and RRDM logic and internal driver
operation. |
Power Windows Operation
The vehicle is equipped with power windows controlled by the door modules. Each
passenger door window can be operated, either from a power window switch built
into the driver door switch assembly (DDSA), or, from a power window switch mounted
locally to the associated door. The driver door window can be operated only from
the driver door power window switch built into the DDSA.
When the driver door window is operated, the DDSA interprets the switch request
and sends it to the DDM. The DDM examines the request and checks to see if it has
received any class 2 serial data messages from any of the other vehicle modules
prohibiting the movement. If no prohibitive messages have been received, the DDM
applies battery voltage and ground to the driver door window motor to move the window
as requested.
When a passenger door module, PDM, LRDM, or RRDM, receives a window switch request
from, either the DDSA, or the window switch mounted locally to its door, the passenger
door module examines the request and checks to see if it has received any messages
from any of the other vehicle modules prohibiting the movement. If no prohibitive
messages have been received, the passenger door module applies battery voltage and
ground to the associated window motor to move the window as requested.
Window Motors
Each power window motor receives battery voltage and ground from the corresponding
door module via the window motor control circuits.The window motors are reversible.
The direction the window moves depends on which motor control circuit the voltage
is applied to, and which motor control circuit the ground is applied to. To move
the window in the Up direction, the module applies voltage to the window motor
Up control circuit, and ground to the window motor Down control circuit. When a window
movement in the opposite direction is needed, the module reverses the polarity and
applies voltage and ground to the opposite circuits to move the window in the reverse
direction. During a window Express operation, the door module applies the voltage
and ground to the window motor until the window is either fully open or fully closed.
Door Modules Power and Ground
In order to control window operations, as well as other door functions, door
modules must be powered up. Battery voltage is supplied by the rear fuse block,
through separate circuits, to each door module. Each door module is separately
grounded through a ground stake. Additionally, the door modules use these power
and ground supplies to provide voltage and ground to their associated window switch,
and to provide voltage and ground for door lock operations. The front door modules
also use these power and ground supplies to power the window express up sensors,
and for outside rearview mirror operation.
Door modules battery voltage is supplied as follows:
• | The DDM battery voltage circuit is fed by the DRVR MDL 10 amp fuse in
the rear fuse block. |
• | The PDM battery voltage circuit is fed by the PASS MDL 10 amp fuse in
the rear fuse block. |
• | The LRDM and RRDM also have separate battery voltage circuits to power
them up, but these circuits are fed by the same EXPORT LTG/PWR LK 15 amp fuse located
in the rear fuse block. |
• | The DDSA receives battery voltage, through the DDM, from the DRVR MDL
10 amp fuse in the rear fuse block . The DDSA is grounded, through the DDM, to
a ground stake. |
These circuits are in the C3 harness connector of each door module and must
not be confused with the battery voltage and ground circuits that are used exclusively
to drive the power window motors. For more information concerning the window motor
power and ground circuits, see the following paragraph titled Window Motors Power
and Ground.
Window Motors Power and Ground
Each door module has a separate battery voltage supply circuit, used exclusively
for power window motor operation. Although the circuits are separate, they are connected
within the rear fuse block, where all are fed by the same PWR WDO 30 amp circuit breaker.
Each door module also has a separate ground circuit used exclusively for power window
motor operation. Each ground circuit is connected to a ground stake. When a door module
drives a power window motor, the door module internally connects these voltage and
ground circuits to the appropriate window motor control circuits. These battery voltage
and ground circuits designated for window motor operation are in the C1 harness connector
of each door module.
Passenger Door Window Switches
Each passenger door has a separate power window switch mounted to it. In order
to receive a signal from their respective switch, each passenger door module, PDM,
LRDM, and RRDM, supplies battery voltage and ground to the associated power window
switch. There are three circuits for battery voltage between each passenger door power
window switch and the corresponding door module, one for an Up signal, one for a Down
signal, and one for an Express signal. The door modules each supply ground to their
switch via a fourth circuit. When the switch is activated for an Up or Down function,
the normally open switch contacts for that function are closed and voltage flows
through the switch, providing the associated door module with the necessary signal.
When the switch is activated for the Express Up or Express Down function, two sets
of switch contacts are closed, first the Up or Down contacts, and then the Express
contacts.
Driver Door Switch Assembly (DDSA)
The driver door switch assembly (DDSA) contains the power window switch for
the driver door window and a power window switch for each one of the passenger door
windows. These switches differ from the individual power window switches mounted
locally to the passenger doors in that, there are no external circuits. The DDSA
is wired to the driver door module (DDM) for battery voltage, ground, and class
2 serial data. The DDSA supplies battery voltage to one side of the contacts of
each of the integral window switches, and ground to the other side of the contacts.
When a DDSA power window switch is operated, the contacts for that switch are closed
to ground and the DDSA interprets the switch signal. The DDSA then sends the appropriate
request message, via the class 2 serial data link, to the appropriate door module
to operate the associated window.
Windows Express Down Feature
All of the windows have the Express Down feature. This allows the windows to
be fully opened by momentarily pressing the appropriate window switch to the second
detente of the Down position. Both the Down contacts and the Express contacts of
the switch are closed. If a passenger door window is operated from its locally mounted
window switch, the door module associated with the switch interprets this two contact
signal as an Express Down request. If the window is operated from the driver door,
the DDSA interprets the two contact switch signal and sends it on, via the class
2 serial data circuit, to the appropriate door module.
Windows Express Up Feature
Both the driver door and the front passenger door have the Express Up feature.
This allows either front door window to be fully closed by momentarily pressing the
appropriate window switch to the second detente of the Up position. Both the Up contacts
and the Express contacts of the switch are closed. When the front passenger door window
is operated from its locally mounted window switch, the front passenger door module
interprets this two contact signal as an Express Up request. When either front door
window is operated from the driver door, the DDSA interprets the two contact switch
signal and sends it on, via the class 2 serial data circuit, to the appropriate front
door module.
Each of the front door window motors has a window sensor mounted to it. The
window sensors detect differences in their respective window motors electrical pulses
to determine if there is an obstruction to the travel of its window glass. If one
of the sensors detects that a passenger, or other obstacle, has become trapped between
the window and window frame, it sends this information, via two communication circuits,
to its associated door module. The door module then takes the appropriate action and,
either disables the Express Up function, or reverses the direction of window travel.
In order to control the Express Up function, each front door module and the
corresponding sensor are wired to each other by four separate circuits, which are
described here. Each front door module supplies battery voltage, via the window
sensor battery positive voltage circuit, and ground, via the window sensor low reference
circuit, to the sensor. Each door module communicates with its sensor via the other
two separate and unique communication circuits. The communication circuits are, the
power window high speed serial data circuit, which is a one-way communications line
from the sensor to the module, and, the power window low speed serial data circuit,
which is a two-way communications line that carries information both ways, from the
sensor to the module, and, from the module to the sensor. State-of-health messages,
the position of the window glass in relationship to the distance traveled by the
window, and the direction in which the window is moving are communicated via these
circuits.
If a front door module looses power for any reason, such as a vehicle battery
disconnect, the window sensor/motor assembly must be reprogrammed once power has
been restored to the door module. Refer to
Window Motor Programming - Express Function
.
Rear Window Lockout Feature
The lockout feature is used to prevent both rear windows from being operated
from their locally mounted switches. The rear window lockout switch is built into,
and receives battery voltage and ground from, the Driver Door Switch Assembly (DDSA).
When the lockout switch is pressed momentarily, the lockout switch contacts are
briefly closed, the LED indicator is illuminated, and the DDSA receives the switch
signal. The DDSA interprets the switch signal and sends it on, via class 2 serial
data message, to the left rear door module (LRDM) and the right rear door module
(RRDM). The LRDM and RRDM then prohibit the rear windows from being operated from
the rear door window switches. When the lockout feature has been activated, both
rear door windows can still be operated from the driver door by using the window switches
built into the DDSA.