Hendrickson Optimaax 17730-310 Instruction Manual

OPTIMAAX®Lift Axle System
Air Controller Module for
Freightliner Vehicles
SUBJECT: Service Instructions
LIT NO: 17730-310
DATE: January 2024 REVISION: F
TABLE OF CONTENTS
Section 1 Introduction ......................2
Section 2 Product Description ................2
Section 3 Important Safety Notice .............4
Section 4 Denitions .......................8
Section 5 Parts List ........................9
Section 6 Air Controller Module .............10
Section 7 Wiring Diagram ..................11
Section 8 Preventive Maintenance ...........12
Section 9 Air Controller Manifold Diagram .....13
Section 10 Vehicle Air Plumbing Diagram.......15
Section 11 System Operation ................16
Section 12 Diagnostic Tool Software ...........17
Section 13 Troubleshooting Guide.............21

Introduction 217730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 1
Introduction
This publication is intended to acquaint and assist maintenance personnel in the preventive mainte-
nance, service, repair and rebuild of the air controller module for Hendrickson’s OPTIMAAX®Lift Axle
System for Freightliner vehicles.
NOTE Use only Hendrickson genuine parts for servicing this system.
Alteration of the OPTIMAAX system air controller module is not permitted.
It is important to read and understand this entire Technical Procedure publication prior to installation
or performing any maintenance,service, repair, or rebuild of this product.The information in this pub-
lication contains parts lists, safety information, product specifications, features, proper maintenance,
service, repair, and rebuild instructions for the OPTIMAAX system air controller.
Hendrickson reserves the right to make changes and improvements to its products and publications at
any time. Contact Hendrickson Truck Tech Services for information on the latest version of this manual
at 1-866-755-5968 (toll-free U.S. and Canada), 1-630-910-2800 (outside U.S. and Canada) or email:
[email protected].
The latest revision of this publication is also available online at www.hendrickson‑intl.com.
SECTION 2
Product Description
Hendrickson’s OPTIMAAX system is a 6 × 2 solution to help fleets save fuel cost,tire wear, and weight
with comparable handling to 6 × 4 tandem axle configurations. Operating as a liftable axle in the for-
ward tandem position, this system provides versatility for fleets with variable loads.
The OPTIMAAX system air controller monitors the air pressure in the drive axle suspension and calcu-
lates axle load based on air pressure levels.When the load reaches a set threshold (programmed by
Hendrickson, where the limiting factor is typically steer axle load) the OPTIMAAX lift axle automatically
deploys.The OPTIMAAX system air controller module includes the air controller manifold,the electronic
control unit (ECU),and the wiring harness (supplied by Freightliner).
Proprietary program logic controls lift axle movement, load transfer,and braking functions.
■ Fully automated controls — Eliminates driver intervention versus conventional 6x2 manual
control systems.Automates axle lowering and lifting by sensing load capacities.
■ Optimized traction and handling — Lifted axle position provides increased traction by increasing
drive axle load.Improved traction when backing under trailers in soft soil or wet conditions versus
the traditional 6 x 2 configuration. Maintains vehicle handling characteristics by keeping the drive
axle behind the fifth wheel.

17730-310 3Product Description
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
FIGURE 2‑1 Air Controller Manifold
FIGURE 2‑2 Electronic Control Unit (ECU)
FIGURE 2‑3 Air Controller Wiring Harness (Supplied by Freightliner)
Vehicles built after October 1, 2019
Freightliner Part No.A06-95748-777
HARN-AXLE-LIFT, OL, CHAS F, HDR
Freightliner Part No.A06-95749-000
HARN-AXLE-LIFT, OL, DASH, HDR, P4
Vehicles built prior to October 1, 2019
Freightliner Part No.A06-95715
HARN-AXLE-LIFT, CHAS, HDR
Freightliner Part No.A06-95709
HARN-AXLE-LIFT, DASH, HDR, P4

Important Safety Notice 417730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 3
Important Safety Notice
Proper maintenance, service, and repair is important for the reliable operation of the suspension.The
procedures recommended by Hendrickson and described in this technical publication are methods of
performing such maintenance,service, and repair.
This technical publication should be read carefully to help prevent personal injury and to assure that
proper methods are used.Improper maintenance, service, or repair may damage the vehicle, cause
personal injury,render it unsafe in operation, or void the manufacturer’s warranty.
Failure to follow the safety precautions in this manual can result in personal injury and / or property
damage. Carefully read and understand all safety related information within this publication, on all
decals and in all such materials provided by the vehicle manufacturer before conducting any mainte-
nance,service or repair.
■ EXPLANATION OF SIGNAL WORDS
Hazard“Signal Words”(Danger-Warning-Caution) appear in various locations throughout this publica-
tion.Information accented by one of these signal words must be observed to help minimize the risk of
personal injury to service personnel,or the possibility of improper service methods which may damage
the vehicle or render it unsafe.
This is the safety alert symbol. It is used to alert you to potential personal injury hazards.
Obey all safety messages that follow this symbol to avoid possible injury or death.
Additional Notes or Service Hints are utilized to emphasize areas of procedural importance
and provide suggestions for ease of repair.The following definitions indicate the use of these signal
words as they appear throughout the publication.
INDICATES AN IMMINENTLY HAZARDOUS SITUATION WHICH, IF NOT AVOIDED,WILL RESULT IN SERIOUS
INJURY OR DEATH.
INDICATES A POTENTIAL HAZARDOUS SITUATION WHICH, IF NOT AVOIDED, COULD RESULT IN SERIOUS
INJURY OR DEATH.
INDICATES A POTENTIAL HAZARDOUS SITUATION WHICH, IF NOT AVOIDED, MAY RESULT IN MINOR OR
MODERATE INJURY,OR PROPERTY DAMAGE.
NOTE An operating procedure,practice condition,etc. which is essential to emphasize.
SERVICE HINT A helpful suggestion that will make the servicing being performed a little easier and / or faster.
Also note that particular service operations may require the use of special tools designed for specific
purposes.These special tools can be found in the Special Tools section of this publication.
The torque symbol alerts you to tighten fasteners to a specified torque value. Refer to the Torque
Specifications section in this publication.
The warnings and cautions should be read carefully to help prevent personal injury and to assure that
proper methods are used.Improper maintenance, service, or repair may damage the vehicle, cause
personal injury,render the vehicle unsafe in operation,or void manufacturer’s warranty.

17730-310 5Important Safety Notice
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
■ SAFETY PRECAUTIONS
FASTENERS
DISCARD USED FASTENERS. ALWAYS USE NEW FASTENERS TO COMPLETE A REPAIR. FAILURE TO DO
SO COULD RESULT IN FAILURE OF THE PART, OR MATING COMPONENTS,ADVERSE VEHICLE HANDLING,
PERSONAL INJURY, OR PROPERTY DAMAGE.
LOOSE OR OVER TORQUED FASTENERS CAN CAUSE COMPONENT DAMAGE, ADVERSE VEHICLE
HANDLING, PROPERTY DAMAGE, OR SEVERE PERSONAL INJURY. MAINTAIN CORRECT TORQUE VALUE
AT ALL TIMES. CHECK TORQUE VALUES ON A REGULAR BASIS AS SPECIFIED, USING A TORQUE WRENCH
THAT IS REGULARLY CALIBRATED.TORQUE VALUES SPECIFIED IN THIS TECHNICAL PUBLICATION ARE FOR
HENDRICKSON SUPPLIED FASTENERS ONLY. IF NON-HENDRICKSON FASTENERS ARE USED, FOLLOW
TORQUE SPECIFICATIONS LISTED IN THE VEHICLE MANUFACTURER’S SERVICE MANUAL.
SUPPORT THE VEHICLE PRIOR TO SERVICING
PLACETHE VEHICLE ON A LEVEL FLOOR AND CHOCK THE WHEELS TO PREVENT THE VEHICLE FROM MOVING
OR ROLLING. DO NOT WORK AROUND OR UNDER A RAISED VEHICLE SUPPORTED BY ONLY A FLOOR JACK.
ALWAYS SUPPORT A RAISED VEHICLE WITH RIGID SAFETY STANDS.FAILURE TO DO SO CAN CAUSE SERIOUS
PERSONAL INJURY OR DAMAGE TO EQUIPMENT.
SUPPORT THE LIFT AXLE PRIOR TO SERVICING
PLACE THE VEHICLE ON A LEVEL FLOOR AND CHOCK THE WHEELS TO HELP PREVENT THE VEHICLE FROM
MOVING. PRIOR TO SERVICING A LIFT AXLE IN THE RAISED POSITION, (1) PROPERLY SUPPORT THE LIFT
AXLE WITH SAFETY STANDS,AND (2) RELEASE ALL AIR PRESSURE IN THE LIFT AXLE AIR SPRINGS AND RIDE
SPRINGS.DO NOT WORK AROUND OR UNDER A RAISED LIFT AXLE SUPPORTED ONLY WITH FLOOR JACKS
OR OTHER LIFTING DEVICES, FAILURE TO DO SO CAN CAUSE DEATH, PERSONAL INJURY, OR DAMAGE TO
COMPONENTS.
PROCEDURES AND TOOLS
A TECHNICIAN USING A SERVICE PROCEDURE OR TOOL WHICH HAS NOT BEEN RECOMMENDED BY
HENDRICKSON MUST FIRST SATISFY THEMSELAVES THAT NEITHER THEIR SAFETY NOR THE VEHICLE’S
SAFETY WILL BE JEOPARDIZED BY THE METHOD OR TOOL SELECTED. INDIVIDUALS DEVIATING IN ANY
MANNER FROM THE INSTRUCTIONS PROVIDED ASSUME ALL RISKS OF POTENTIAL PERSONAL INJURY OR
DAMAGE TO EQUIPMENT INVOLVED.
PERSONNEL PROTECTIVE EQUIPMENT
ALWAYS WEAR PROPER EYE PROTECTION AND OTHER REQUIRED PERSONAL PROTECTIVE EQUIPMENT TO
HELP PREVENT PERSONAL INJURY WHEN PERFORMING VEHICLE MAINTENANCE,REPAIR OR SERVICE.
MODIFYING COMPONENTS
DO NOT MODIFY OR REWORK PARTS WITHOUT AUTHORIZATION FROM HENDRICKSON. DO NOT
SUBSTITUTE REPLACEMENT COMPONENTS NOT AUTHORIZED BY HENDRICKSON. USE OF MODIFIED,
REWORKED, SUBSTITUTE OR REPLACEMENT PARTS NOT AUTHORIZED BY HENDRICKSON MAY NOT MEET
HENDRICKSON’S SPECIFICATIONS,AND CAN RESULT IN FAILURE OF THE PART,ADVERSE VEHICLE HANDLING,
POSSIBLE PERSONAL INJURY OR PROPERTY DAMAGE,AND WILL VOID ANY APPLICABLE WARRANTIES.USE
ONLY HENDRICKSON AUTHORIZED REPLACEMENT PARTS.
ELECTRICAL SYSTEM
DO NOT WORK ON THE VEHICLE ELECTRICAL SYSTEM WITH THE VEHICLE POWER ON. DAMAGE TO THE
VEHICLE‘S ELECTRICAL SYSTEM AND / OR UNEXPECTED AXLE MOVEMENT MAY RESULT.
WIRING HARNESS
ENSURE THERE IS SUFFICIENT FREE MOVEMENT IN THE AIR CONTROLLER WIRING HARNESS TO PREVENT
WIRES AND CONNECTIONS FROM BEING UNDER TENSION DURING INSTALLATION. FAILURE TO DO SO MAY
DAMAGE OR FRAY THE CABLES.

Important Safety Notice 617730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
FIGURE 3‑1 Product / Safety Decal 60905‑048
NOTE REPLACE ANY SAFETY DECALS THAT ARE FADED,TORN,
MISSING, ILLEGIBLE, OR OTHERWISE DAMAGED. CONTACT
HENDRICKSON TO ORDER REPLACEMENT LABELS.
LIFT AXLE RAPID AUTOMATIC MOVEMENT
LIFT AXLE RAPID, AUTOMATIC MOVEMENT CAN CAUSE
SEVERE PERSONAL INJURY OR DEATH.
THE LIFT AXLE CONTROL SYSTEM IS PROGRAMMED TO
AUTOMATICALLY:
LOWER THE LIFT AXLE IF –
■ A LOAD ON THE PRIMARY REAR SUSPENSION IS
ABOVE A PRESET VALUE, OR
■ THE PARKING BRAKE IS ENGAGED, OR
■ THE IGNITION SWITCH IS OFF, OR
■ A MAJOR SYSTEM FAULT IS DETECTED
RAISE THE LIFT AXLE IF –
■ 1) THE PARKING BRAKE IS DISENGAGED, AND 2)
A LOAD ON THE PRIMARY REAR SUSPENSION IS
BELOW A PRE-SET VALUE.
LIFT AXLE LOADING / UNLOADING
■ ENSURE ALL PERSONNEL ARE CLEAR OF THE LIFT AXLE DURING VEHICLE LOADING / UNLOADING AND
OPERATION.
■ ENGAGE THE PARKING BRAKE DURING VEHICLE LOADING / UNLOADING.
PRIOR TO SERVICE
PRIOR TO WORKING ON OR AROUND THE LIFT AXLE:
■ EXHAUST ALL PRESSURE IN LIFT AXLE AIR SPRINGS AND VEHICLE AIR SYSTEM.
■ REMOVE 15 AMP FUSE FROM THE LOCATION DESIGNATED BY THE VEHICLE MANUFACTURER FOR
OPTIMAAX SUSPENSION, REFER TO THE SYSTEM OPERATION SECTION OF THIS PUBLICATION.
AIR CONTROLLER MANIFOLD
HOT AIR CONTROLLER MANIFOLD SURFACE CAN CAUSE BURNS. DO NOT TOUCH.ALLOW MANIFOLD TO
COOL BEFORE SERVICING,SEE FIGURES 3-2 AND 3-3.
FIGURE 3‑2 Safety Decal 60905‑030 FIGURE 3‑3

17730-310 7Important Safety Notice
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SYSTEM INSTALLATION
IT IS THE RESPONSIBILITY OF THE INSTALLER OF THE AIR CONTROLLER MODULE AND OTHER OPTIMAAX
SYSTEM COMPONENTS TO ENSURE PROPER INSTALLATION.ANY INSTALLATION DEVIATIONS MUST BE
APPROVED,IN WRITING,BY HENDRICKSON’S PRODUCT ENGINEERING DEPARTMENT.ANNUAL INSPECTION
OF SYSTEM PRESSURE SENSORS IS REQUIRED TO CHECK FOR PROPER LOADING ON DRIVE AXLE AND
STEER AXLE. FAILURE TO COMPLY WITH ANY OF THE ABOVE WILL VOID APPLICABLE WARRANTIES.
AIR SPRING INFLATION AND DEFLATION
PRIOR TO DISASSEMBLY OF THE SUSPENSION, AIR SPRING ASSEMBLIES MUST BE DEFLATED.
UNRESTRICTED AIR SPRING ASSEMBLIES CAN VIOLENTLY SHIFT.DO NOT INFLATE AIR SPRING ASSEMBLIES
WHEN THEY ARE UNRESTRICTED.AIR SPRING ASSEMBLIES MUST BE RESTRICTED BY SUSPENSION OR
OTHER ADEQUATE STRUCTURE. DO NOT INFLATE BEYOND PRESSURES RECOMMENDED BY AIR SPRING
MANUFACTURER, CONTACT HENDRICKSON TECHNICAL SERVICES FOR DETAILS. IMPROPER USE OR OVER
INFLATION MAY CAUSE AIR SPRING ASSEMBLIES TO BURST, CAUSING PROPERTY DAMAGE AND / OR
SEVERE PERSONAL INJURY.
PRIOR TO AND DURING DEFLATION AND INFLATION OF THE AIR SUSPENSION SYSTEM, ENSURE ALL
PERSONNEL AND EQUIPMENT ARE CLEAR FROM UNDER THE VEHICLE AND AROUND THE SERVICE AREA,
FAILURE TO DO SO CAN CAUSE SERIOUS PERSONAL INJURY, DEATH,OR PROPERTY DAMAGE.
AIR SPRING INFLATION
INFLATE THE SUSPENSION SLOWLY AND ENSURE THE RUBBER BLADDER OF THE AIR SPRING INFLATES
UNIFORMLY AND IS NOT BINDING. FAILURE TO DO SO CAN CAUSE DAMAGE TO THE AIR SPRING AND / OR
MOUNTING BRACKETS AND VOID WARRANTY.

Denitions 817730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 4
Definitions
DEFINITIONS
APU Auxiliary Power Unit
Bobtail Condition A bobtail truck is a semi-truck that travels from one point to another
without a trailer.
CAN BUS Controller Area Network Bus
CAN Wires Controller Area Network Wires
Diagnostic Tool Software Software used to communicate with the lift axle
ECU Electronic Control Unit
EEPROM Electrically Erasable Programmable Read-only Memory
OBD Onboard Diagnostics
Fault Code
Diagnostic trouble codes are codes that are stored by the on-board
computer diagnostic system.These are stored in response to a
problem found in the vehicle by the system.
SSAM Single Signal-detection and Activation Module
SPN Suspect Parameter Number is a code assigned to specic
parameters per SAE (Society of Automotive Engineers)
USB Universal Serial Bus
VPDM Vehicle Power Distribution Module

17730-310 9Parts List
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 5
Parts List
KEY
NO. PART NO. DESCRIPTION VEHICLE QUANTITY
TORQUE
VALUE
1 093267-0XX *OPTIMAAX Air Controller Module, Includes Key Nos. 2-3, 8, 11,
Replaces 080924-0XX and 080692-0XX 1
2 060905-051 Warning Decal 2
3 093265-0XX Electronic Control Unit (ECU),Includes Key Nos.4-7
Replaces 080925-0XX and 080427-0XX 1
4 060905-052 OPTIMAAX ECU Decal (Located on the hanger and/or fairing) 1
5**ECU Hardware 1
6**OPTIMAAX EEPROM 1
7**OPTIMAAX Programing Decal 1
8 080860-000 Splash Shield Assembly, Includes Key Nos. 9-10 1
9 060905-030 Manifold Heat Warning Decal 1
10 077276-000 Splash Shield 1
11 91984-000 Air Controller Manifold 1
12 ***M5 x 16 mm Screw 6
13 ***M5 Flange Hex Nut 653 ± 9 in lbs.
NOTE: * Consult the vehicle manufacturer for applicable OPTIMAAX Air Controller Module.
** Item included in kit / assembly only,part not sold separately.
*** Fasteners and torque value supplied by the vehicle manufacturer.Contact the vehicle manufacturer for additional service
information.

Air Controller Module 10 17730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 6
Air Controller Module
INSTALLATION
ASSEMBLY
1. Prior to installation of the air controller module, refer to Cautions and Warnings in the Important
Safety Notice section of this publication
DO NOT WORK ON THE VEHICLE ELECTRICAL SYSTEM WITH THE VEHICLE POWER ON. DAMAGE TO THE
VEHICLE ELECTRICAL SYSTEM AND / OR UNEXPECTED AXLE MOVEMENT MAY RESULT.
NOTE Refer to the Wiring Diagram section of this publication for basic routing / schematic of wires.
2. Chock the wheels and exhaust all air from the vehicle supply tanks.
PRIOR TO AND DURING DEFLATION AND INFLATION OF THE AIR SUSPENSION SYSTEM, ENSURE THAT ALL
PERSONNEL AND EQUIPMENT ARE CLEAR FROM UNDER THE VEHICLE AND AROUND THE SERVICE AREA,
FAILURE TO DO SO CAN CAUSE SERIOUS PERSONAL INJURY,DEATH, OR PROPERTY DAMAGE.
3. See additional Air Spring Cautions and Warnings in the Important Safety Notice section of this
publication prior to deflating or inflating the air system.
4. Ensure vehicle power is off.
5. Remove the 15 AMP fuse from the location designated by the vehicle manufacturer for OPTIMAAX
suspension in the dashboard behind the VPDM (vehicle power distribution module), see Figure
11-3 in the System Operation section of this publication.
6. Ensure the wiring harness is plugged into the ECU and the air controller manifold per the vehicle
manufacturer’s specifications. Harness connectors have printing (A,B,C,D,E) to indicate which
manifold connectors to mate with.The manifold is engraved with matching letters, see the Wiring
Diagram section of this publication.
■ The wiring harness pressure connector labeled DRIVE matches the manifold port engraved
DRIVE.The harness pressure connector labeled LIFT matches with the remaining manifold port.
■ Ensure the wiring harness is secured as per the vehicle manufacturer’s guidelines. For a worn
or frayed harness, contact the vehicle manufacturer.
DO NOT WORK ON THE VEHICLE ELECTRICAL SYSTEM WITH THE VEHICLE POWER ON. DAMAGE TO THE
VEHICLE‘S ELECTRICAL SYSTEM AND / OR UNEXPECTED AXLE MOVEMENT MAY RESULT.
7. Connect the lift axle air plumbing to the OPTIMAAX air manifold per the Air Manifold Diagram sec-
tion of this publication.
8. Install the splash shield over the OPTIMAAX ECU.
9. See additional Air Spring Cautions and Warnings in the Important Safety Notice section of this
publication prior to deflating or inflating the air system.
10. Reconnect vehicle power and start the engine.
11. Re-insert the 15 AMP fuse in the location designated by the vehicle manufacturer for OPTIMAAX
suspension in the dashboard behind the VPDM.
12. Allow the compressor to generate full system pressure.With the wheels still chocked,cycle vehicle
parking brake to verify system operation.
■ The lift axle should always remain on the ground with the parking brake set.At bobtail condi-
tion, the lift axle should raise when the parking brake is released.
13. Remove the wheel chocks.

17730-310 11 Wiring Diagram
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 7
Wiring Diagram
ELECTRONIC CONTROL UNIT for AIR CONTROLS
ECU Part Number Deployment
Threshold
Lbs.
Retract
Threshold
Lbs.
Vehicles Built
After
10/1/2019
Vehicles Built
Prior To
10/1/2019
*080925-001 080427-001 11,000 12,000
*080925-002 080427-002 12,000 13,000
**093265-003 080427-003 13,000 14,000
**093265-004 080427-004 14,000 15,000
**093265-005 080427-005 15,000 16,000
**093265-006 080427-006 16,000 17,000
**093265-007 080427-007 17,000 18,000
**093265-008 080427-008 18,000 19,000
093265-009 19,000 20,000
*093265-010 *20,000 *21,000
* No longer available, contact Hendrickson for a replacement part.
** Replaces part number 080925-0XX.
THE ADDITION OF WEIGHT TO THE VEHICLE (APU - AUXILIARY POWER UNIT, CHAINS, ETC.) MAY CHANGE THE
CORRECT OPTIMAAX DEPLOYMENT THRESHOLD AND MAY REQUIRE REPLACEMENT OF THE ECU. FAILURE TO
DO SO WILL OVERLOAD THE LIFT AXLE.

Preventive Maintenance 12 17730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 8
Preventive Maintenance
AIR CONTROLLER MANIFOLD
An appropriate inspection procedure is important to ensure the OPTIMAAX system is accurately mea-
suring the system load.
■ On an annual basis – calibrate the pressure sensors in the air controller manifold, see
Figure8-1.
CALIBRATION
1. Connect the Diagnostic Tool Software.
2. With a calibrated pressure gauge apply shop air to the drive port.
3. The displayed pressure in the Diagnostic Tool Software must match pressure gauge measurement
within ± 5PSI.If not, the air controller manifold must be replaced.
4. Repeat Steps 2 and 3 for the lift port.
FIGURE 8‑1
DRIVE AXLE AIR SPRINGS
NOTE The OPTIMAAX controller is calibrated for Freightliner OEM air springs.Air springs must be replaced with
only Freightliner OEM air springs for the OPTIMAAX controller to function properly.
Hendrickson OPTIMAAX Diagnostic Tool
File Log Tools Help
Displayed pressure
must match the
pressure gauge
measurement

17730-310 13 Air Controller Manifold Diagram
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 9
Air Controller Manifold Diagram
TUBING REPLACEMENT
FOR THE AIR PORT EXH ON THE AIR CONTROLLER MANIFOLD, USE A FILTER RATEDTO AT LEAST 40 MICRONS.
ANYTHING LESS CAN CAUSE DAMAGE TO THE AIR CONTROL PANEL.
1. Use only S.A.E. J844 tubing and ensure all tubes are free from kinks.
2. Ensure that the minimum bend radius is achieved on all tubes prior to assembly,see Table 9-1.
TABLE 9‑1
Tube Size Recommended Minimum Radius
¼" 1.0"
3⁄8" 1.5"
½" 2.0"
3. Use only dedicated tube cutters when preparing tube ends for insertion into push-in fittings.
4. Ensure the tube ends are square,free of damage,and clean.
5. Ensure the tube is fully inserted into the fittings (tube ends are pushed past both the grip ring and
the sealing O-ring).
■ SUPPLY and LIFT ½" tubes (not supplied by Hendrickson)
■ AUX and DRIVE 3⁄8" tubes (not supplied by Hendrickson)
6. A spring is used to retain a mesh filter on DRIVE and SUPPLY ports.These must be retained when
PTC fittings are installed (not supplied by Hendrickson).The mesh filter helps to prevent debris from
entering the system.
7. Ensure the tubing is not under any tension.
FIGURE 9‑1

Air Controller Manifold Diagram 14 17730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
FIGURE 9‑2

17730-310 15 Vehicle Air Plumbing Diagram
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 10
Vehicle Air Plumbing Diagram

System Operation 16 17730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 11
System Operation
Prior to operating the system, refer to Safety Precautions in the Important Safety Notice section of this
publication.
■ The OPTIMAAX is designed with features to detect a fault in the system operation which is separate
from the air controller module.
SYSTEM FAULT
FIGURE 11‑1
FIGURE 11‑2
FIGURE 11‑3
Prior to service of the lift axle,adjacent components,or the air controller module:
a. Turn the ignition off.
b. Ensure the lift axle is on the ground.
c. Remove the 15 AMP fuse from the location designated by the vehicle manufacturer for OPTIMAAX
suspension in the dashboard behind the VPDM (vehicle power distribution module), which
houses the main fuse and relay center,see Figure 11-3.
d. Exhaust all pressure in the lift axle air springs and vehicle air system.
NOTE The OPTIMAAX air controller module weight thresholds to raise and deploy the lift axle are set by the
vehicle manufacturer.
VEHICLES BUILT AFTER TO OCTOBER 1, 2019
The Pop Up Display in the instrument cluster, see Figure 11-1, indicates any OPTIMAAX fault.
VEHICLES BUILT PRIOR TO OCTOBER 1, 2019
The warning light on the dashboard,see Figure 11-2,indicates either of the following conditions:
A FLASHING WARNING Light indicates a system fault.Refer to the Diagnostic Tool Software sec-
tion for reading ECU system faults and the Troubleshooting Guide section of this publication.
A SOLID WARNING LIGHT indicates an overload condition of the suspension. It may be ben-
eficial to weigh the vehicle to verify overload condition.The OPTIMAAX system is designed to help
ensure that the lift,drive,and steer axles operate within the proper weight parameters.An overload
light will indicate an overload on at least one of the axles.
Vehicle Power
Distribution Module
(VPDM)
Remove the 15 AMP fuse
in line with wiring harness
(fuse location designated
by the vehicle manufacturer
for OPTIMAAX suspension)

17730-310 17 Diagnostic Tool Software
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
SECTION 12
Diagnostic Tool Software
FEATURES AND OPERATION
SYSTEM MINIMUM REQUIREMENTS AND OPERATING SYSTEMS
This Diagnostic Tool Software works with a laptop equipped with a 32-bit or 64-bit Windows®XP,Vista,
and Windows 7,8,and 10 operating systems.Hendrickson provides access to software through NEXIQ,
www.nexiq.com.
THE DIAGNOSTIC TOOL SOFTWARE
It is used to communicate with the lift axle controls.It allows the user to monitor system function, and
troubleshoot system operation.
SERIAL PORT AND USB TO SERIAL CABLE
The serial port must be selected in the Diagnostic Tool Software.If using a USB to serial converter, the
software for the USB device must be installed first and connected to the computer to check the settings.
FIGURE 12‑1
OPENING THE DIAGNOSTIC TOOL SOFTWARE
You will need:
■ USB to RS232 Cable 6.26' (2.00m) Shielded (not supplied),see
Figure12-1.
Manufacturer: Future Technology Devices International Ltd.
Part Number: UT232R-200
1. Locate the serial port cable, typically located in the dash behind the vehicle power distribution
module (VPDM) which houses the main fuse and relay center, and plug into it using the USB to
serial cable,see Figure 12-1.
2. With the ignition on and the parking brake engaged, open the Diagnostic Tool Software, see
Figure12-2.
3. DO NOT turn off the vehicle power when the software is open. It is recommended to keep the
engine running while connected so the air is available to test system operation.
4. Select a COM port from the pull down menu, see Figure 12-2. Select one port and click Open.
5. If the wrong COM port is selected, the software will show an error message as shown in Figure
12-3. Select another COM port until the software opens.
6. Once the connection is made, the software version and serial number will be displayed in the
white box,see Figure 12-4.
7. Click on the History tab to view error/fault codes (also known as SPN), see Figures 12-4 and 12-6.
Also, refer to OPTIMAAX Lift Axle System (OLA) – Fault Codes in the Troubleshooting section of this
publication.

Diagnostic Tool Software 18 17730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
FIGURE 12‑2
FIGURE 12‑3
FIGURE 12‑4
Hendrickson OPTIMAAX Diagnostic Tool
File Log Tools Help
Select a COM Port
from the pull down menu.
There may be more than
one com port available.
Pick one,
and click Open
Hendrickson OPTIMAAX Diagnostic Tool
File Log Tools Help
Select another COM Port
untill the software opens
and select OK
If the wrong
COM Port is selected,
the software will show
an Error message
Hendrickson OPTIMAAX Diagnostic Tool
File Log Tools Help
The screen will look
like this when the
software is
communicating
with the controller
Click on the History tab
to view Error / Fault Codes

17730-310 19 Diagnostic Tool Software
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
FIGURE 12‑5
FIGURE 12‑6
Hendrickson OPTIMAAX Diagnostic Tool
File Log Tools Help
Digital #2
represents the
parking brake signal
Hendrickson OPTIMAAX Diagnostic Tool
File Log Tools Help
Click on the
History tab
to view
ASECU current
Error / Fault Codes
Click here to
view ASECU
Log Data

Diagnostic Tool Software 20 17730-310
OPTIMAAX®Lift Axle System Air Controller Module for Freightliner
EXITING THE DIAGNOSTIC TOOL SOFTWARE
ALWAYS EXIT THE DIAGNOSTIC TOOL SOFTWARE PROPERLY, ONLY DISCONNECT THE CABLE AFTER EXITING
THE SOFTWARE.FAILURE TO DO SO CAN CORRUPT INFORMATION STORED ON THE ECU.
Always exit and open the Diagnostic Tool Software properly.
1. Prior to exiting the Diagnostic Tool Software,ENGAGE the parking brake.
2. Press the CLOSE button on the START tab to terminate communication with the lift axle ECU, see
Figure 12-7.
3. Exit the window, see Figure 12-7.
FIGURE 12‑7
IMPROPER EXIT OF THE DIAGNOSTIC TOOL SOFTWARE
NOTE It may be necessary to cycle the ignition switch (key).
Hendrickson OPTIMAAX Diagnostic Tool
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STEP 2
Click Close to exit
STEP 3
Exit
window
The OPTIMAAX axle will not lift if the Diagnostic Tool Software is not exited properly.
If this occurs, RECONNECT the Diagnostic Tool Software and press the CLOSE button to
exit properly.