2005-2007 Uplander, SV6, Relay, Terraza PSD
Posted to Technical Tips Forum on 10/7/2006
11 Replies
I ran into this the other day and thought it would be
helpful.
I had an 05 Chevy Uplander van with dual Power Sliding
Doors (PSD). The complaint I will deal with here is "When
closing the Passenger side door, the motor labors for a
while then pops back out."
A quick check of both power doors for operation showed that
the left side door acted normally, the motor pulling the
door closed to just past the fully latched position, then
stopping and going back to the proper latch position. The
right side door would pull closed, and continue pulling the
door inwards for a few seconds past the latch condition,
the motor would time-out and the door would pop back out.
This is the same thing as a motor-run-on condition.
I checked for DTC's, none were shown, both doors had been
learned (according to scan data) and this problem had
attempted repairs at another place, including a reflash
which addresses a different concern. I took a look at scan
data for both doors to see if there was anything in there
of value, I did find there was...once I understood exactly
what is going on here, I knew how to fix it. The Left Power
Sliding Door data "PSD Detent Switch" PID would clearly
show two detent switches consistantly during the latching
of the door while the right side sometimes would only
flicker a second switched position.
Service information in description and operation only
mentions the detent switch is used for determining the
proper latched position. I deduced, and later confirmed
that it needs to see 2 detent switch changes of state to
know when to back off and center the latch. The rear of the
door has a latch that activates a detent switch just before
and just after the latched position. The PSDM looks for the
first on state, an off state, then the second on state,
then it allows the door to fall back to the off state, that
being the proper latched position. The detent switch goes
through the plunger contacts at the front of the door, as
such there will be some plunger bouncing so the PSDM's
filter out some of that and look for clear changes of
state.
Here are some captures to follow along:
Here is the left side door, which was working
properly. Note it rolls it past the first on
state, into the off state, then into the next on state,
lets off and the door reverses by turning the motor into
the idle state and commanding the motor clutch inactive,
letting the door back up into the latch.
here is the right side door before repair.
Note it rolls quickly past the two detent states, the motor
continues to run well past the latched position until it
gives up then turns the motor to idle and deactivates the
motor clutch, allowing the door to pop back out to the
latch.
There was a PI for these doors that referred to a know-how
video that was broadcast. It covered much of what is
already available in service information regarding
adjustment procedures and actuator replacements. They also
reinforced the importance of making sure the door rolls,
opens, and closes as easily as possible. But they also
briefly mentioned that if the door closes too easily, then
it could cause a run-on condition. This is exactly what was
going on with this vehicle. After adjusting the rear
striker to achieve proper body fitment and still having the
concern, I proceded to pull the door in at the top of the
front of the door using the upper roller bracket where
it bolts to the door (which is adjustable with those two
bolts). Note, you will need to remove the PSD
fuse from the IP fuse panel to do work on these doors. The
doors will feel and operate like a normal door with this
fuse out and will give you a good idea of how the rolling,
opening, and closing feels. I adjusted that upper bracket
until I found a good compromise between feel and fit. After
the adjustment, I closed the door and reinstalled the PSD
fuse. I then used the key fob to open and close both doors
twice to relearn the motor positions. Scan data confirms
the learn with a switch from a no to a yes. I also noted
the problem was now resolved.
Here is the capture I took from the RPSDM after the
repair.. Note the door is slowed down in the
latching portion, this is due to increased contact with the
door seals. This allows the PSDM to properly recognize the
detent switches, allowing it to make the proper
determination of the latched position.
Here is a side-by-side-by-side of the portions of
interest in the three captures. These are
exactly the same amount of time side by side by side. You
can clearly see the difference in the three situations.
Rags
Matthew from Wyoming
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