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XL-AS20015BM-en-US Rev B · 2019-09-05 · Amendments and Errors Reserved · © SAF-HOLLAND, Inc., SAF-HOLLAND, HOLLAND, SAF,
and logos are trademarks of SAF-HOLLAND S.A., SAF-HOLLAND GmbH, and SAF-HOLLAND, Inc.
Troubleshooting
PROBLEM
POSSIBLE CAUSE
POSSIBLE REMEDY
Tire Pressure HIGH
and Warning Light
is OFF
Low supply pressure
Incoming pressure must be greater than 100psi, or desired tire pr10psi
(whichever value is higher). Correct as necessary.
Above Mechanical Limits of system
System is designed to relieve tire pressure up to a maximum of 4psi above the
regulator setting. If tire pressure is more than 4psi above regulator setting, excess tire
pressure must be manually relieved.
Tire Pressure in-spec
and Warning Light
is ON
Air system valve closed
Open valve
Inadequate supply pressure
Supply pressure must be a minimum of 10psi greater than the desired tire pressure.
Correct as necessary.
Inadequate supply voltage
Supply voltage must be a minimum of 12V DC. Correct as necessary
Defective Pressure Protection Valve
Replace pressure protection valve
Note: System cannot use the same PPV as the air suspension. A dedicated port on the
air tank is required with a dedicated pressure protection valve.
Defective pressure switch
Replace pressure switch
Defective solenoid valve
Replace control box assembly
Defective indicator light switch
Replace indicator light switch
Note: If regulator setting is changed from the factory setting, a new indicator light
switch may be required for proper functionality. Reference installation manual for
additional details.
Regulator out of adjustment
Adjust regulator
Defective regulator
Replace control box assembly
Corroded butt connectors at solenoid Replace butt connectors
Loose/leaking air lines or fittings
Spray all air lines and fittings with soapy water and repair leaks as needed
Leaking rotary union
Replace rotary union
Tire Pressure in-spec
and Warning Light
is OFF
System is working as designed, no issue
Air Leak from axle
vent
Damaged/loose airlines or
connections inside the axle
Remove spindle plug assemblies, inspect air line connections and repair as necessary
Leaking rotary union
Replace rotary union
Loose and/or leaking air lines
and/or fittings
Spray all air lines and fittings with soapy water and repair leaks as needed
Air Leak from Tire
Hose
Overtightened connections
Tire hose fittings should be hand tightened. Over-tightened fittings can damage the
o-rings inside the fitting. Inspect o-rings for damage and replace as necessary.
Brake air tank
de-pressurized or low
pressure
Defective pressure protection valve
Replace pressure protection valve
Note: System cannot use the same PPV as the air suspension. A dedicated port on the
air tank is required with a dedicated pressure protection valve.
Air leak between air tank and
pressure protection valve
Spray all air lines and fittings with soapy water and repair leaks as needed
