Check leveling system automatically.

The AUTOMATIC LEVELING sequence is comprised of first the LEVELING MODE then followed by the STABILIZE MODE.

This sequence can be found in here, on pages MI91.328T and U.

  • Turn the Ignition to the ON position
  • Apply the park brake
  • Depress AUTO LEVEL button on the touch panel
System
Functioned
System
Malfunctioned

AUTOMATIC LEVELING DIAGNOSTICS

  • THE AUTO LEVEL LIGHT WILL NOT FLASH WHEN THE AUTO LEVEL BUTTON IS PUSHED. THE "NOT IN PARK / BRAKE" LIGHT ON THE TOUCH PANEL IS NOT COMING ON. Push any manual UP ARROW button. If the system functions, replace the touch panel. If the system does not function, review STEP 5.
  • THE AUTO LEVEL LIGHT WILL NOT FLASH WHEN THE AUTO LEVEL BUTTON IS PUSHED. THE "NOT IN PARK BRAKE" LIGHT ON THE TOUCH PANEL IS COMING ON WHILE THE AUTO LEVEL BUTTON IS PUSHED. Review STEP 5 for park brake issues.
  • THE AUTO LEVEL LIGHT FLASHES BUT THE SYSTEM IS NOT FUNCTIONING PROPERLY. Review STEP 5.
  • Retest AUTO LEVEL.
System
functioned
System malfunctioned
during STABILIZE MODE
Touch Panel reads
EXCESS SLOPE

STABILIZE MODE DIAGNOSTICS

  • The stabilize mode starts automatically after all of the yellow level lights have gone out.
  • Unplug the level sensing unit when checking stabilize mode issues. With the sensing unit unplugged, the system will think the vehicle is level and always go immediately into the stabilize mode. Always start with the jacks retracted to make the following tests.

A. A JACK THAT IS BEING EXTENDED DURING THE STABILIZE MODE DOES NOT QUITE REACH THE GROUND OR DOES NOT LIFT THE VEHICLE ENOUGH (1/4 TO 3/4 INCH) TO STABILIZE PROPERLY. Adjusting the jack pressure switch should take care of this. Unplug the jack pressure switch and loosen the jam nut at the top of the switch. Turn the threaded body of the switch clockwise 1/4 turn and retry. Remember to plug the switch back in. Repeat as necessary until the jack extends enough to stabilize the vehicle properly. If the threaded body is turned several full turns with no results, replace the jack pressure switch. Click here, and see page MP84.9690.

B. A JACK WILL NOT EXTEND AT ALL DURING THE STABILIZE MODE. Try to extend the jack using he appropriate manual UP ARROW button. If the jack does not extend, review PART 7a. If the jack extends manually, the problem is the jack pressure switch, a shorted wire to ground or a problem with the I/O module. Unplug the jack pressure switch and retry. If the jack now extends, the jack pressure switch should be replaced. If the jack still does not extend, unplug the switch and use a volt meter to check the harness wire. If there is voltage on the wire, replace the I/O module. If there is no voltage on the wire, unplug the 35 pin connector from the I/O module. Check the pressure switch wire in the harness for a short to ground. With both ends of the wire unplugged, the wire should show an open circuit. If necessary, repair the wire. If the wire is OK, replace the I/O module. Click here, and see page MP84.3174.

C. A JACK EXTENDS AND LIFTS THE VEHICLE MORE THAN 3/4 INCH BUT DOES NOT FULLY EXTEND. Try to adjust the jack pressure switch. Unplug the switch and loosen the pressure switch jam nut at the top of the switch. Turn the threaded body of the jack pressure switch counter-clockwise 1/4 turn and retry. Remember to plug the pressure switch back in. Repeat the adjustment as needed. If the threaded body is turned several complete turns with no results, replace the jack pressure switch. Click here, and see page MP84.9690.

D. A REAR JACK CONTINUES TO EXTEND COMPLETELY AFTER REACHING THE GROUND AND THE PUMP WILL NOT SHUT OFF. The jack pressure switch will not come on, there is a break in the harness wire for the switch or the I/O module is the problem. Unplug the jack pressure switch. Use a small jumper wire to ground the pin in the harness plug and retry. If the jack will now not extend, the jack pressure switch should be replaced. If the jack still extends, unplug the 35 pin connector at the I/O module and check the appropriate wire for continuity from end to end. Fix the wire as necessary. If the wire is OK, replace the I/O module. Click here, and see page MP84.3130.

E. BOTH FRONT JACKS CONTINUE TO EXTEND COMPLETELY AFTER REACHING THE GROUND AND THE PUMP WILL NOT SHUT OFF. One or both jack pressure switches will not come on, there is a break in the harness wire for one or both switches; or the I/O module is the problem. Unplug both front jack pressure switches and use small jumper wires to ground the pins in the harness plugs for both switches and retry. Neither jack should extend. Click here, and see page MP84.9690.

  • Both jacks still extend. The problem is in the harness or the I/O module. Unplug the 35 pin connector at the I/O module. Check both front pressure switch wires in the harness for continuity from end to end of the wire. Fix the wire(s) as necessary. If the wires are OK, replace the I/O module. Click here, and see page MP84.3174.
  • Neither jack will extend. One or both of the jack pressure switches are not working properly. Remove one jumper wire, plug that jack pressure switch back in and retry. When the jack with the plugged in pressure switch reaches the ground and lifts slightly, both jacks should stop extending. If the jacks continue to extend, the jack pressure switch that is plugged in needs to be replaced. Repeat this test, reversing the position of the jumper wire to check the other front jack pressure switch. Click here, and see page MP84.3130.

Note: In the stabilize mode, if a pressure switch is not coming on, the pump will continue to run after the jack reaches full extension. This will cause the 3000 psi manifold pressure switch to come on. If the pump runs for 20 seconds after the manifold pressure switch comes on, the "EXCESS SLOPE" light on the touch panel will come on.

RESTART TEST

EXCESS SLOPE

EXCESS SLOPE HAPPENS DURING THE AUTOMATIC LEVELING MODE WHEN TWO JACKS REACH FULL EXTENSION AND ONE OR MORE YELLOW LEVEL LIGHTS REMAIN ON. WHEN THIS HAPPENS, THE 3000# PRESSURE SWITCH ON THE MANIFOLD CLOSES SENDING A GROUND SIGNAL TO THE I/O MODULE. THE PUMP WILL SHUT OFF, THE SYSTEM WILL NOT STABILIZE AND THE TOUCH PANEL WILL TURN OFF WITH THE "EXCESS SLOPE" LIGHT REMAINING ON UNTIL THE JACKS ARE COMPLETELY RETRACTED WITH THE "STORE" BUTTON OR THE PARK BRAKE IS RELEASED.

Note: The leveling system manifold has a 50 psi pressure switch and a 3000 psi pressure switch. Be careful to not interchange the 3000 psi switch with the 50 psi switch. Be careful to not interchange the 3000 psi switch with the 50 psi switch.

IMPORTANT: DO NOT LET THE PUMP RUN FOR MORE THAN SEVERAL MINUTES AT A TIME WHEN PERFORMING EXCESS SLOPE TESTS. ALLOW THE PUMP MOTOR TO COOL IF THE MOTOR STARTS TO BECOME HOT.

1. TWO JACKS ARE FULLY EXTENDED WITH A YELLOW LEVEL LIGHT STILL ON. THE PUMP CONTINUES TO RUN AND THE SYSTEM WILL NOT SHOW "EXCESS SLOPE". The 3000 psi manifold pressure switch is bad, the 8100 pressure switch wire is bad, the pump is not developing enough pressure or the I/O module is the problem. In some cases, the shuttle valve may be the problem (STEP 3A). Unplug the 3000 psi manifold pressure switch. Use a small jumper wire to ground the pin for the 8100 wire in the harness plug. Retry automatic leveling. The "EXCESS SLOPE" light should come on about 2 seconds after the pump starts to run and the pump should shut off. If the "EXCESS SLOPE" light comes on, the pressure switch is bad or the pump pressure is low (STEP 3). If the "EXCESS SLOPE" light does not come on, the 8100 wire or the I/O module is bad. Click here, and see page MP84.3240.

  • The "EXCESS SLOPE" light comes on and the pump shuts off. Pump pressure and voltage have been checked from previous tests. Replace the 3000 psi manifold pressure switch.
  • The "EXCESS SLOPE" light does not come on and the pump continues to run. Unplug the 3000 psi pressure switch and unplug the 35 pin connector at the I/O module. Check for continuity between the pins for the 8100 pressure switch wire. Repair the wire if necessary. If the 8100 wire is OK, replace the I/O module. Click here, and see page MP84.3174.

2. TWO JACKS ARE NOT FULLY EXTENDED BUT THE "EXCESS SLOPE" LIGHT IS COMING ON AND THE PUMP IS SHUTTING OFF. There are two possibilities. The 3000 psi manifold pressure switch is coming on too soon or the vehicle weight may be greater than the capacity of the jacks. To test the pressure switch, retract the jacks with the "STORE" button. Install a 5000 psi pressure gauge inline with the shuttle valve. Put the system in the automatic level mode and monitor the pressure gauge to see when the "EXCESS SLOPE" light comes on. If the pressure switch is coming on too low, replace the pressure switch. If the pressure switch is coming on at 3000 psi or more, the capacity of the jacks may be the issue. Contact HWH Technical Service for assistance. Click here, and see page MP64.3917.

RESTART TEST

AUTOMATIC STORE (RETRACT) SEQUENCE

  1. The ignition must be in the ON or ACC. position. If the ignition is in the ON position, the master warning light and buzzer will be on while the jacks are retracting. The "STORE" button will function with the park brake released.
  2. Push the "STORE" button. The store indicator light should start flashing.
  3. The two front jacks should start to retract as soon as the "STORE" button is pushed.
  4. Five seconds after the front jacks start to retract, the rear jacks will start to retract.
  5. Each individual jack warning light will go out as the jack retracts to within approximately 1/2 inch of being fully retracted.
  6. One (1) minute after the last red jack warning light goes out, the store indicator light will go out. The "TRAVEL MODE" light will be on and if the park brake is set (with the ignition in ON or ACC.) one or two yellow level indicator lights may be on. If the ignition is in the ON position, the master warning light and buzzer will turn off at this time.

Note: If one or more jacks will not retract and / or red jack down warning lights remain on, the system will stay in the STORE mode for fifty (50) minutes from the time the "STORE" button was pushed. The "TRAVEL MODE" light will not be on. Any lit red warning lights will remain on. After fifty (50) minutes, the store indicator light will go out. The "TRAVEL MODE" light will remain off. Any red warning lights that were on will stay on.

System functioned
End of Diagnostics
System malfunctioned

AUTOMATIC STORE DIAGNOSTICS

  • Almost all diagnostics for problems encountered during the auto store sequence will be diagnosed in STEP4 and STEP 5.
    THE STORE INDICATOR LIGHT WILL NOT COME ON AND FLASH WHEN THE "STORE" BUTTON IS PUSHED. Push any UP or DOWN ARROW button. If any manual buttons function, replace the touch panel. If no buttons on the touch panel function, restart diagnostics with STEP 5.
Restart test