Go Back   Ford Truck Enthusiasts Forums > Newer Light Duty Trucks > Expedition & Navigator
Sign in using an external account
Register Forgot Password?


Expedition & Navigator 1997 - 2002 and 2003 - 2006 Ford Expedition and Lincoln Navigator SPONSORED BY:

Welcome to Ford-Trucks Forums!
Welcome to Ford-Trucks.com.

You are currently viewing our forums as a guest, which gives you limited access to view most discussions and access our other features. By joining our community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join the Ford-Trucks Forums community today!





 
Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 12-07-2009, 08:39 AM
vze2sgxa vze2sgxa is offline
Senior User
 
Join Date: Nov 2003
Location: Where the war is...
Posts: 467
vze2sgxa is starting off with a positive reputation.
Question Ford LLS air suspension control module characteristics, inputs, & outputs

Ford LLS air suspension control module (p/n YU7Z14B205AA), for a 99-03 Expedition 4x4 system:

- Does anybody know the performance characteristics or logic pattern of this module wrt compressor control? ie. What is the 'compressor time-out' feature and what is the designed duration?

- Does the LLS control module actually send an electric signal to tell the compressor to operate it's internal vent solenoid or is that a mechanical feature of the compressor?

- In all cases where a 'CHK SUSP' light comes on, does that mean it always shuts off the compressor and will not come back on until it is reset?

- Does opening and closing the driver's door 'reset' the 'CHK SUSP' light the same way that restarting the engine or cycling the compressor service cut off switch does?

- Where is the 'steering wheel rotation sensor' and 'brake pedal position switch' located? Are these sensors known to fail?

- To remove the LLS control module, the manual says to 'Remove the instrument panel cluster panel' - how is that done? The module is mounted directly over the radio. What else do you have to remove besides the front radio/hvac control trim panel to get at the LLS control module?
__________________
2008 Escape Ltd 4X4/V-6, 40k as of Feb 2011. (I miss my 2000 Expy - it was a tank ... but it saved me in that accident.)
Reply With Quote
  #2  
Old 12-07-2009, 10:23 PM
lsrx101 lsrx101 is offline
Moderator
 
Join Date: Feb 2006
Location: Lorain County, Ohio
Posts: 1,775
lsrx101 has a very good reputation on FTE.lsrx101 has a very good reputation on FTE.lsrx101 has a very good reputation on FTE.
Ford LLS air suspension control module (p/n YU7Z14B205AA), for a 99-03 Expedition 4x4 system:

- Does anybody know the performance characteristics or logic pattern of this module wrt compressor control? ie. What is the 'compressor time-out' feature and what is the designed duration?

The basic operation is:
The control module reads inputs from the wheel speed sensors, door latch switches and other sensors (I don't have the manual handy) and controls the compressor, spring solenoids and vent solenoid to keep the vehicle at a pre determined height.
The logic sequence is thoroughly outlined in the service manual.

The compressor Time Out feature is to protect the compressor in the event of a leak in the system. The compressor has a fairly short duty cycle and is not designed to "keep up" with a leak. I can't say exactly what the spec is, but the time out interval is about 1-2 minutes. If the vehicle doesn't reach trim height in that time, the module disables the compressor and illuminates the suspension warning lamp.

- Does the LLS control module actually send an electric signal to tell the compressor to operate it's internal vent solenoid or is that a mechanical feature of the compressor?

The control module controls the vent valve. It is electrically separate from the compressor.

- In all cases where a 'CHK SUSP' light comes on, does that mean it always shuts off the compressor and will not come back on until it is reset?

Yes.

- Does opening and closing the driver's door 'reset' the 'CHK SUSP' light the same way that restarting the engine or cycling the compressor service cut off switch does?

No. The drivers door switch only tells the module if the door is open or closed. This is to prevent the system from venting or filling while the door is open.

- Where is the 'steering wheel rotation sensor' and 'brake pedal position switch' located? Are these sensors known to fail?

The steering wheel rotation sensor is on the base of the steering column. It "reads" a notched ring on the steering shaft.
The Brake Pedal Position Sensor is the brake lamp switch, mounted near the brake pedal shaft.
The rotation sensor is not known to fail very often at all, I've never seen one fail. Brake switches do fail occasionally, as indicated by the brake lamps being inoperative.

- To remove the LLS control module, the manual says to 'Remove the instrument panel cluster panel' - how is that done? The module is mounted directly over the radio. What else do you have to remove besides the front radio/hvac control trim panel to get at the LLS control module?

For this information, you really should source a factory shop manual. There is very seldom any reason to remove the module, they rarely fail.

Hope this helps.
__________________
Sometime I wish I didn't know now
The things I didn't know then.
Give me something to believe in!
Reply With Quote
  #3  
Old 12-08-2009, 07:37 AM
vze2sgxa vze2sgxa is offline
Senior User
 
Join Date: Nov 2003
Location: Where the war is...
Posts: 467
vze2sgxa is starting off with a positive reputation.
This is great, thanks

Awesome reply, on all accounts; I do have the 2 volume factory service manual and will recheck the circuits/components there, but this does fill in a lot of information. Thanks!

Quote:
Originally Posted by lsrx101 View Post
Ford LLS air suspension control module (p/n YU7Z14B205AA), for a 99-03 Expedition 4x4 system:

- Does anybody know the performance characteristics or logic pattern of this module wrt compressor control? ie. What is the 'compressor time-out' feature and what is the designed duration?

The basic operation is:
The control module reads inputs from the wheel speed sensors, door latch switches and other sensors (I don't have the manual handy) and controls the compressor, spring solenoids and vent solenoid to keep the vehicle at a pre determined height.
The logic sequence is thoroughly outlined in the service manual.

The compressor Time Out feature is to protect the compressor in the event of a leak in the system. The compressor has a fairly short duty cycle and is not designed to "keep up" with a leak. I can't say exactly what the spec is, but the time out interval is about 1-2 minutes. If the vehicle doesn't reach trim height in that time, the module disables the compressor and illuminates the suspension warning lamp.

- Does the LLS control module actually send an electric signal to tell the compressor to operate it's internal vent solenoid or is that a mechanical feature of the compressor?

The control module controls the vent valve. It is electrically separate from the compressor.

- In all cases where a 'CHK SUSP' light comes on, does that mean it always shuts off the compressor and will not come back on until it is reset?

Yes.

- Does opening and closing the driver's door 'reset' the 'CHK SUSP' light the same way that restarting the engine or cycling the compressor service cut off switch does?

No. The drivers door switch only tells the module if the door is open or closed. This is to prevent the system from venting or filling while the door is open.

- Where is the 'steering wheel rotation sensor' and 'brake pedal position switch' located? Are these sensors known to fail?

The steering wheel rotation sensor is on the base of the steering column. It "reads" a notched ring on the steering shaft.
The Brake Pedal Position Sensor is the brake lamp switch, mounted near the brake pedal shaft.
The rotation sensor is not known to fail very often at all, I've never seen one fail. Brake switches do fail occasionally, as indicated by the brake lamps being inoperative.

- To remove the LLS control module, the manual says to 'Remove the instrument panel cluster panel' - how is that done? The module is mounted directly over the radio. What else do you have to remove besides the front radio/hvac control trim panel to get at the LLS control module?

For this information, you really should source a factory shop manual. There is very seldom any reason to remove the module, they rarely fail.

Hope this helps.
__________________
2008 Escape Ltd 4X4/V-6, 40k as of Feb 2011. (I miss my 2000 Expy - it was a tank ... but it saved me in that accident.)
Reply With Quote
Old 12-08-2009, 07:37 AM
 
 
 
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Specific LLS Component Questions vze2sgxa Expedition & Navigator 11 04-09-2010 11:06 PM
Navi Suspension headache (yet again) mudder1_2000 Expedition & Navigator 19 12-13-2009 02:23 AM
F150/Expedition LLS control module characteristics, inputs, & outputs vze2sgxa 1997 - 2003 F150 0 12-07-2009 12:02 PM
Specific LLS Component Questions vze2sgxa 1997 - 2003 F150 0 12-04-2009 11:56 AM
2000 Lincoln Navigator LLS Suspension Air Ride Trouble orange_x_crush Expedition & Navigator 2 03-28-2006 09:29 PM


Go Back   Ford Truck Enthusiasts Forums > Newer Light Duty Trucks > Expedition & Navigator

Tags
1999, 2000, 98, 99, air, control, expedition, ford, lincoln, location, module, navigator, parts, suspension, yu7z14b205aa

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump



All times are GMT -5. The time now is 03:02 AM.


Powered by vBulletin® Version 3.8.7 AC1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup