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SERVICE MANUAL
SERVICE MANUAL
ML31043/MI91.0024
06MAY04
Touch Panel Leveling Control
BI-AXIS Air Leveling
FEATURING:
HWH CORPORATION
(On I-80, Exit 267 South)
2096 Moscow Road | Moscow, Iowa 52760
Ph: 800/321-3494 (or) 563/724-3396 | Fax: 563/724-3408
www.hwh.com
2000 SERIES AIR LEVELING SYSTEM
HWH COMPUTER-CONTROLLED
R
(With or Without Tag Axle)
W
CORPORATION
H
H
R
R
NOT IN
BRAKE
PARK /
TRAVEL
MODE
CAUTION!
SECURELY BEFORE REMOVING TIRES OR CRAWLING UNDER VEHICLE.
UNDERSTAND OPERATORS MANUAL BEFORE USING. BLOCK FRAME AND TIRES
DUMP
RAISE
STOP
EMERGENCY
TRAVEL
MODE
SLOPE
EXCESS
HWH COMPUTERIZED LEVELING
LEVEL
AIR SECTION 1
MI91.115C
27OCT03
SECTION
2
FIGURES
SECTION
1
TROUBLE
SHOOTING
GUIDE
2 PART FOLDER
HOW TO USE MANUAL
Before beginning your repair, it is IMPORTANT to read the CAUTIONS and NOTES AND CHECKS in the first section, TROUBLE
SHOOTING GUIDE. In many cases this will save time and mistakes when trouble shooting a system.
This Repair Manual is offered as a guide only. It is impossible to anticipate every problem or combination of problems. For
any problems encountered that are not addressed in this manual, contact HWH Corporation for assistance. (800-321-3494)
PROCEED WITH TROUBLE SHOOTING GUIDE
This manual is written in two sections. Section 1 is the Trouble Shooting Guide. Section 2 is the figures. Begin diagnosis of
the system with Section 1, the Trouble Shooting Guide. The Trouble Shooting Guide describes system operation with each
phase of operation followed by symptoms of possible problems. The problem section is broken into 3 columns, Problem,
Solutions and Figures. Under Problems, find the symptom you have encountered. The testing and repair for that problem is
in the Solution (center) column. Diagrams for a particular Problem and Solution are in the Figures (right hand) column. This
column will direct you to the proper figure in Section 2, Figures, for a more detailed view. TROUBLE SHOOTING
MI91.115F
05DEC06
CAUTIONS!
BLOCK FRAME AND TIRES SECURELY BEFORE CRAWLING UNDER VEHICLE. DO NOT USE AIR SUSPEN-
SION TO SUPPORT VEHICLE WHILE UNDER VEHICLE OR CHANGING TIRES. VEHICLE MAY DROP AND OR
MOVE FORWARD OR BACKWARD WITHOUT WARNING CAUSING INJURY OR DEATH.
SAFETY CLASSES ARE TO BE WORN TO PROTECT EYES FROM DIRT, METAL CHIPS, OIL LEAKS, ETC. FOLLOW
ALL OTHER SHOP SAFETY PRACTICES.
NOTES AND CHECKS
Read and check before preceding with Trouble Shooting Steps.
NOTE: HWH CORPORATION ASSUMES NO LIABILITY
FOR DAMAGES OR INJURIES RESULTING FROM THE
INSTALLATION OR REPAIR OF THIS PRODUCT.
1. The trouble shooting guide must be followed in order. Prob-
lems checked for in one step are assumed correct and not
checked again in following steps.
2. Batteries should be in good condition and fully charged. Low
voltage can cause erratic operation.
3. Do not replace the control box unless the repair steps say
to replace it. Otherwise the malfunctions may damage the
new control box.
This manual is intended for use by experienced mechanics
with knowledge of air suspension and automotive electrical
systems. People with little or no experience with HWH
leveling systems should contact HWH technical service
(800-321-3494) before beginning. Special attention should
be given to all cautions, wiring, and air diagrams.
Special note: When installing a new control box, make
sure the box is properly grounded before applying power
to the system.
Suggested tools for trouble shooting the HWH leveling systems:
JUMPER WIRES(UP TO 10 GAUGE)
MULTI-METER
12 VOLT TEST LIGHT
PROCEED WITH THE TROUBLE
SHOOTING STEPS ON THE
FOLLOWING PAGE
DO NOT EXCEED 5 MPH OR TRAVEL LONG DISTANCES WHEN THE SUSPENSION IS NOT AT THE PROPER
RIDE HEIGHT.
4. If the control box is removed, +12 ignition power must be
applied to the travel solenoid wires (GRAY) 1700 in the front
and (GRAY) 3700 in the rear air harnesses. This will allow the
height control valve to function. See MP85.040C of section (2)
Diagrams.
Important: Not all vehicle air suspensions are plumbed
the same. Consult the vehicle manufacturer for specific
plumbing diagrams.
Also, not all vehicles employ the speed switch to latch
the "DUMP" or "RAISE" buttons in. These systems will
have momentary "DUMP" and "RAISE" buttons. CONTROL IDENTIFICATION
"EMERGENCY STOP" BUTTON
"EXCESS SLOPE"
"NOT IN PARK"
RAISE RIGHT SIDE BUTTON
LOWER RIGHT SIDE BUTTON
LEVELING LIGHTS
(4 - Yellow)
WARNING LIGHTS
(4 - Red)
RAISE REAR BUTTON
LOWER REAR BUTTON
"AIR" (ON) BUTTON
DUMP LIGHT
"TRAVEL MODE" BUTTON
"TRAVEL MODE"
This button will lower the whole coach by
dumping air from the suspension system.
This button will raise the whole coach
by adding air to the suspension system.
ON if the leveling system
can NOT level the coach.
CONTROL BUTTONS
MI91.202C
12DEC03
CONTROL FUNCTIONS
LEVELING SYSTEM
"DUMP" BUTTON
RAISE LEFT SIDE
BUTTON

LOWER LEFT SIDE
BUTTON
RAISE FRONT BUTTON
LOWER FRONT BUTTON
Flashes when "RAISE" button is pushed.
"AIR" BUTTON:
"DUMP" BUTTON:
"RAISE" BUTTON:
UP ARROWS (RAISE BUTTONS):
DOWN ARROWS (LOWER BUTTONS):
IMPORTANT:
DUMP LIGHT:
RAISE LIGHT:
"EXCESS SLOPE" LIGHT:
WARNING LIGHTS:
LEVELING LIGHTS:
"NOT IN PARK/BRAKE" LIGHT:
LIGHT
LIGHT
Flashes when "DUMP" button is pushed.
This is the system active and automatic
operation button. It works if the ignition is in the "ON" position.
These momentary
buttons are used for manually operating the air leveling
systems. Sides or ends of the vehicle will lower while these
buttons are pushed.
One or two yellow lights can be on
indicating the side, end or corner of the coach is low.
Function with the ignition in the
"ON" position. ON when the LEVELING SYSTEM ACTIVE
LIGHT is ON. See PREPARATION FOR TRAVEL.
Read "DUMP AND RAISE FUNCTIONS"
before using the "DUMP" or "RAISE" buttons.
CAUTION!
HWH COMPUTERIZED LEVELING
UNDERSTAND OPERATORS MANUAL BEFORE USING. BLOCK FRAME AND TIRES
SECURELY BEFORE REMOVING TIRES OR CRAWLING UNDER VEHICLE.
NOT IN
PARK /
BRAKE
DUMP
RAISE
EMERGENCY
STOP
AIR
TRAVEL
TRAVEL
EXCESS
SLOPE
RAISE LIGHT
"RAISE" BUTTON
"EMERGENCY STOP" BUTTON: This button turns the
"RAISE" buttons. Pushing this button will NOT put the system
system OFF but does NOT control power to the "DUMP" or
"TRAVEL MODE" BUTTON:
LEVEL SYSTEM ACTIVE LIGHT: ON when the system is
active, and flashes during automatic leveling.
"TRAVEL MODE" LIGHT (GREEN):
INDICATOR LIGHTS
"TRAVEL MODE" BUTTON LIGHT (RED):
This button will put the Leveling
System in the TRAVEL mode. The ignition must be "ON" for
ON if the ignition is in
the "ON" position, the system is not being used, and there is
sufficient air pressure in the suspension.
"TRAVEL MODE" BUTTON
LIGHT (Red)
Light flashes
for 3 seconds after the "TRAVEL MODE" button is pushed.
the vehicle to return to proper ride height for traveling.
ON while the "AIR" button
is being pushed if the Park Brake is NOT set. The light will go
out when the "AIR" button is released.
HARD RESET SWITCH
(SEE HWH LIGHTED RESET SWITCH)
MASTER WARNING LIGHT
These momentary
buttons are used for manually operating the air leveling
systems. Sides or ends of the vehicle will raise while these
buttons are pushed.
ACTIVE LIGHT
LIGHT (Green)
MODE
MODE
in the TRAVEL mode.
See PREPARATION FOR TRAVEL.
ON any time the
MASTER WARNING LIGHT:
"TRAVEL" light is not ON, if the ignition is in the
"ON" position. TROUBLE SHOOTING
MI91.232A
29JAN07
When trouble shooting the 2000 series leveling system, it is
best to run the system in the manual mode to check individual
functions before operating the system in the automatic mode.
Start the engine and push the "TRAVEL" button. Let air
pressure build and allow the vehicle to return to travel height.
If the vehicle is equipped with a tag axle, make sure the TAG
DUMP switch is in the normal travel position. This will make
the following procedures easier to perform. If the vehicle will
not return to ride height see step 1c.
When trouble shooting raise, lower or travel mode problems,
do not watch the vehicle. Watch the air bags. Make sure air
bags will deflate completely when dumping or re-inflate when
raising. Check all four sets of up and down arrows. Do a
lower then raise check for one set of arrows at a a time. It is
important to do only one set of arrows at a a time to avoid
twisting unless this manual calls for a specific operating
procedure.
Each air manifold is equipped with two 20 P.S.I. pressure
switches. The contacts in these switches will close if the air
pressure in the corresponding bag(s) is 20 P.S.I. or less.
These switches are used as low air warning devices and
also protect the vehicle from twisting while air is being
dumped during manual or automatic leveling. Any time
either front pressure switch is on, a manual or automatic
front lower procedure will cease. Any time either rear (drive
axle) pressure switch is on, a manual or automatic rear lower
procedure will cease. Side lower procedures, either manual
or automatic will not be affected by low air pressure in any
air bag(s).
If the vehicle is equipped with a tag axle, there will be an a