2012 Expy - Odd Thumping Sound

[ExpyKen]

Hello All,

Purchased a new 2012 Expy for my wife back in January - about a week ago she noted an odd noise coming from the rear compartment ... I've been in the vehicle a few times over the past week and heard it myself. The is coming from the rear compartment ... I've had it happen at about any speed, though it's intermittent, has happened when the Expy was stopped as well. Tonight I got in, started it up (the AC was not on) and the sound started ... I immediately turned the vehicle off and removed the key and the sound continued for another 10-15 seconds or so. I've checked inside and out, including underneath - can't determine where/what is causing this.

Any thoughts?

Thank you!

 

[RI-Matt]

Do you have the rear load leveling air suspension?


Matt

 

[ExpyKen]

Hi Matt,

Yes, I believe I do - this is a 4x2 King Ranch. Think that could be it?

Best,

Ken

 

[RI-Matt]

It's the only thing that comes to mind for the rear end making noise especially when the vehicle is off.

According to the service manual:

■When the key is in the ON position, the load leveling feature automatically makes adjustments to the vehicle height so that the vehicle is always at target height and constant front-to-rear vehicle attitudes are maintained over the load range of the vehicle.
■When the key is in the OFF position, the system will remain active for 40 minutes after the ignition is turned off to make limited height adjustments as necessary.

Maybe the height adjustment sensors are out of adjustment and need to be recalibrated.


Matt

 

[ExpyKen]

Matt,

Very, very interesting. Do you know - is recalibration of those sensors something that the dealer has to do?

Best,

Ken

 

[RI-Matt]

Ken,

Yes, I believe its a dealer only thing.


From the Manual:

Ride Height Adjustments
Special Tool(s) Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool


CAUTION: The suspension ride height dimensions are for reference only. The vehicle attitude must be controlled by the correct dimensions to prevent vehicle damage.

NOTE: If one or both height sensors are installed new, both height sensors must be calibrated.

NOTE: Incorrect air suspension ride height can be caused by an air suspension system that is incorrectly set.

NOTE: The air suspension module has a preprogrammed trim height.

1.NOTE: The vehicle must be on a level surface, such as a drive on alignment hoist.

Position the vehicle on a level surface.

2.Using the vehicle message center, verify that the air suspension is in the ON mode. For additional information, refer to Air Suspension System Disable/Enable in this section.

3.Using the scan tool, run the accurate trim test.

4.Measure the ride height. For additional information, refer to Section 204-00.

5.If the ride height is not within specification, use the scan tool to vent or fill the air suspension to the correct dimension.

6.NOTE: The air suspension height sensor sends a signal to the air suspension module. The output ranges from approximately 4.5 volts at minimum height (when the vehicle is low or in full jounce) to 0.5 volt at maximum height (when the vehicle is in high or in full rebound).

Using the scan tool, monitor the 2 suspension height sensors voltage PIDs.

7.Using the scan tool, save the vehicle's trim height for both sensors.



Matt

 

[CARO'S98EB]

I think it is probaly the blend door motor for the rear heat/air they go bad sometimes. you are under warranty[by time miles?] so take it to the dealer.