Power Liftgate System Control Parameters

The power liftgate system is designed with a number of control parameters, which are conditions that must be fulfilled to allow operation. These control parameters are listed below:

The Power Liftgate module will inhibit operation of the power liftgate in extreme temperatures. These temperatures will be approximately -22° F (-30° C) and 149° F (65° C). The pinch sensor/thermistor assembly on the right side of the liftgate monitors the temperature.
The vehicle's transmission must be in park or neutral for the power liftgate to operate.
The vehicle's speed must be zero for the power liftgate to operate.
The vehicle's electrical system voltage must be within specification for the power liftgate system to operate. A low-voltage cut-off is built into the power liftgate system to prevent the vehicle's battery from discharging to the point were the vehicle cannot be operated.
If the vehicle's ignition switch is in the "START" position, the power liftgate system will not initiate a power cycle.
If the vehicle's ignition switch is moved to the "START" position during a power cycle, the power liftgate will pause.
If the vehicle is locked, the outside handle will not release the latch. The key fob and overhead switch will work for power open or close cycles.
If the vehicle's theft alarm is armed, the overhead switch will not open the liftgate; however the key fob will work.
If a liftgate pinch sensor is activated during a power close, the liftgate will reverse direction. If a pinch sensor is already active the power liftgate will not initiate a power close. A pinch activation during latch cinch will stop the cinch operation.
If something sufficiently impedes liftgate travel, the power liftgate will detect an obstacle and reverse direction, traveling to full open or closed.
If multiple obstacles are detected during the same power open or close cycle, the liftgate will abort that power cycle and go into full manual operation.
The power liftgate components are protected by the power liftgate fuse. If the fuse is blown, the power liftgate will not function. Refer to Vehicle Quick Reference/Fuse Locations and Types - Specifications .
If severe Diagnostic Trouble Codes (DTC's) are stored in the power liftgate control module the system may not operate. If power liftgate DTC's are present, refer to POWER LIFTGATE - ELECTRICAL DIAGNOSTICS .

POWER LIFTGATE INPUT - OUTPUT TABLE

INPUT	NORMAL READINGS			DESCRIPTION
-	FULLY CLOSED AND LATCHED	FULLY OPEN	BETWEEN FULLY OPEN AND CLOSED	-
PRIMARY RATCHET/AJAR SWITCH CLOSED	FALSE	TRUE	TRUE	Primary/Ajar switch, internal to the liftgate latch. Open when latch is in primary; Closed when latch is out of primary.
SECONDARY RATCHET SWITCH CLOSED	FALSE	TRUE	TRUE	Internal to the liftgate latch. Indicates when the latch is in secondary position. Open when in secondary position; Closed when out of secondary position.
PAWL SWITCH CLOSED	FALSE	TRUE	TRUE	Internal to the liftgate latch. Indicates when the latch pawl has secured the latch in primary or secondary position. Goes Open when entering secondary latch; Closed when out of secondary and primary.
SECTOR GEAR SWITCH CLOSED	FALSE	FALSE	FALSE	Internal to the liftgate latch. Essentially a park switch for the latch. When latch is running a cinch or release, this switch is closed. After cinch or release is complete, the Power Liftgate Module will reverse direction of the latch until the switch is Open.
FULL OPEN SWITCH CLOSED	FALSE	TRUE	FALSE	Internal to the drive motor. Indicates when the liftgate is a few degrees from full open. Closed when full open; Open otherwise.
POSITION SENSOR NUMBER 1 AND NUMBER 2 CLOSED	FALSE OR TRUE	FALSE OR TRUE	FALSE OR TRUE	When in motion, these signals will toggle between Open and Closed. The two signals together tell the Power Liftgate Module the speed and direction of liftgate travel. They are also used to sense obstacles encountered by the liftgate.
POSITION SENSOR NUMBER 1 PULSE COUNTS	0	180 - 200	0 to 200	This is a counter derived from the pulses coming from Position Sensors number 1 and 2. This count represents total travel of the liftgate (to mechanical end of travel).
GATE POSITION COUNTS	0	165 - 185	0 to 185	This is a counter derived from the pulses coming from Position Sensors number 1 and 2. This count represents the position of the full open switch in the liftgate drive unit.
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LEFT PINCH SENSOR	Approximately 2.5V (10K ohms)		Less than 1V	Pinch sensor reads 10K ohms when not pinched. When pinched, shorts out the 10K ohm resistor and should read from 0 to approximately 200 ohms.
RIGHT PINCH SENSOR	Approximately 1.7V at 70°F		Less than 1V	Right pinch sensor has a 10K at room temperature thermistor in place of the resistor. When not pinched, resistance is proportional to the ambient temperature. When pinched, shorts out the thermistor and should read from 0 to approximately 200 ohms.
HANDLE SWITCH	5V (normally open)		Approximately 2.2V (4.7K ohms pressed)	Located in the liftgate latch. Open circuit when not active. 4.7K ohms to ground when handle is activated.
OVERHEAD SWITCH	Approximately 4.7V		Approximately 2.2V	When not pressed, should read about 810K ohms. When pressed, should read about 4.7K ohms.
D-PILLAR/REAR ZONE SWITCH (IF EQUIPPED)	Approximately 4.7V		Approximately 2.2V	When not pressed, should read about 810K ohms. When pressed, should read about 4.7K ohms.
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OUTPUT	DESCRIPTION		DIAGNOSE
HALL EFFECT POWER	Provides +5V to the hall sensor in drive motor		As long as module is awake it should read approximately +5V.
LATCH MOTOR	Provides +/- 12V to latch motor for cinch and release		Actuate with scan tool. Should see positive voltage on the cinch wiring connector terminal for cinch direction. Should see positive voltage on the release wiring connector terminal for release direction. Refer to the appropriate wiring diagrams for specific wiring harness and connector pinout information.
DRIVE CLUTCH	Provides + 12V to clutch in power liftgate drive unit to engage drive mechanism for power open or close		Actuate with scan tool. Should see approximately 12V output.
DRIVE MOTOR	Provides +/- 12V to power liftgate drive unit motor for power open or close		Actuate with scan tool. Should see positive voltage on the open wiring connector terminal for open direction. Should see positive voltage on the close wiring connector terminal for close direction. Refer to the appropriate wiring diagrams for specific wiring harness and connector pinout information.