Master Tech,

My 2005 Grand Caravan SXT would not electronically open or close. Now it electronically will open but closing only goes a 3rd of the way then opens back up. It seems like it senses an obstruction in the way. Where do I start troubleshooting??
Thank you,
Jeff

 

Does it seem to close easily manually?

 

Yes it closes manually. As far as easily, no, but I replaced both struts 2 months ago so they are stiff.
Also when I said initially it did not open or close when it tried to open, the lock mechanism released the door but would not open the door. Now it opens ok but won't close.
Hope that wasn't too confusing...jeff

 

That's weird Jeff. 95% of the time it's the hatch won't open. If it tries to close and then reopens, at least the motor is engaging. If you just replaced the hatch props, then it may need to be relearned. It is possible that doing a hard disconnect of the battery may improve your operation. Disconnect both battery cables from the battery and then touch them together for a minute or so and then leave the battery disconnected for 5 minutes. Reconnect and then try the hatch, if the memory was cleared, it will have to learn hatch operation again. If it still doesn't work, could have other issues that would probably require a scan tool to diagnose.

 

You are right that it's weird. Also, I forgot to say that it was working fine after I replaced the props. But now it's being difficult. I'll try disconnecting the battery & I'll let you know the results.
Thank you for your time!!

 

Tizzy1...tried the battery path disconnect but still no joy. Is there a sensor/microswitch possibly feeding false info to the electronic brain? Im grasping at anything to understand my situation...Jeff

 

Here is the operation explanation. But yes, it is probably sensing something funky and it will be hard for you to tell without a scan tool. There could be a code in the module, not sure if autozone or someone could pull it for you.


OPERATION
With the push of a power liftgate open/close command switch (key fob or overhead console mounted) a signal is sent out on the Programmable Communication Interface (PCI) Data Bus circuit. This signal is detected at the Body Control Module (BCM). The BCM then sends a signal out on the PCI Data Bus circuit to the power liftgate control module. The power liftgate control module then signals the power liftgate motor to start an open or close cycle, depending on what position the liftgate is in.

During a liftgate open or close cycle, if the power liftgate module detects sufficient resistance to liftgate travel, such as an obstruction in the path of the liftgate, the power liftgate control module will immediately stop the liftgate movement and reverse travel to the full open or closed position. The ability for the power liftgate module to detect resistance to liftgate travel is accomplished by hall effect sensors, drive motor speed and pinch sensors (tape switches).

Anytime the liftgate is opened or closed using the power liftgate system the power liftgate control module learns from the cycle. If a replacement power liftgate component is installed or a liftgate adjustment is made, the module will relearn the effort and/or time required to open or close the liftgate. This learn cycle can be performed with a DRB III®, or equivalent scan tool, or with a complete cycle of the liftgate, using any one of the command switches. (Refer to 8 - ELECTRICAL/POWER DOORS - STANDARD PROCEDURE) for detailed instructions.

The power liftgate system is designed with a number of system inhibitors. These inhibitors are necessary for safety and / or feasibility of the power liftgate system. The power liftgate system inhibitors are:

The Power Liftgate may not operate in extreme temperatures. These extreme temperatures will be approximately less than -12° F (-24.4° C) or greater than 143° F (61.6° C). A chime/thermister assembly in the rear light bar assembly monitors the outside temperature.
The vehicle transmission must be in Park or Neutral for the power liftgate to start a cycle.
If multiple obstacles are detected during the same power open or close cycle, the liftgate goes into manual operation.
If severe problems occur, Diagnostic Trouble Codes (DTC) are stored in the power liftgate control module.
POWER LIFTGATE SYSTEM CAUTIONS AND WARNINGS
WARNING: ALWAYS DISCONNECT THE BATTERY NEGATIVE CABLE BEFORE ATTEMPTING ANY POWER LIFTGATE SYSTEM SERVICE.

WARNING: THERE IS A SMALL AREA ON BOTH SIDES OF THE LOWER POWER LIFTGATE WHICH IS NOT PROTECTED BY PINCH SENSORS. EXTREME CARE MUST BE TAKEN TO PREVENT OBJECTS FROM ENTERING THIS AREA ONCE THE LIFTGATE REACHES THE SECONDARY LATCH CONTACT (APPROXIMATELY 1/2 INCH BEFORE FULLY CLOSED).

WARNING: NEVER ATTEMPT TO ENTER OR EXIT THE VEHICLE WITH THE LIFTGATE IN MOTION. YOU COULD DAMAGE THE POWER LIFTGATE SYSTEM AND/OR COMPONENTS AND/OR CAUSE PERSONAL INJURY.

WARNING: NEVER STICK OBJECTS IN THE POWER LIFTGATE WHEN CINCHING CLOSED. YOU COULD DAMAGE THE VEHICLE, POWER LIFTGATE SYSTEM COMPONENTS AND/OR CAUSE PERSONAL INJURY.

 

Tizzy1, Sorry this reply took so long as I was incognito so to speak!! You got me thinking about module re-learning...so I assisted (pushing down) the liftgate while closing a couple of times and it started working correctly on it's own. I have not had a problem since I performed this assistance. Now that is really weird but successful.\Thank you for your help!! jeff
Now I have an issue with my daughters Jeep...but I'll start a new thread.

 

I'm amazed that the battery disconnect didn't cause a relearn but that's kinda what I thought the issue was. It gets used to the weak props and you put new ones on an it sees it as an obstruction. Glad we could help.