Mec Speed Level 2684 RT Service And Parts Manual page 173

No drive elevated Unit out of level
Batteries discharged
System interlock
Slow drive with High torque enabled
platform in stowed
position
Elevation sensor out of calibration
Malfunctioning rear wheel bypass valve
Wheel motor/s not functioning correctly
Poor gradability High or Mid Speed enabled
performance
Batteries discharged
Wheel motor/s not functioning correctly
Malfunctioning Rear wheel bypass valve
Malfunctioning Series/Parallel Valves
Worn hydraulic pump
Drive in one direction Drive Valve SVD1 not energizing in one
only direction
Counterbalance Valve CBV1 or CBV2
malfunction
No output from GP400
No Low Speed (high Speed/torque selector switch inoperative
torque mode)
Valve SV3 not functioning
EP1 poppet valve not functioning
No Mid Speed SV3 or SV4 powered and/or shifted
Speed/torque selector switch malfunction
No High Speed Speed/torque selector switch inoperative
Valve SV4 not functioning
EP2 poppet valve not functioning
No brake effectiveness Brake Orifice OD-1 obstructed
Brake discs worn past service limit
"3084 Speed Level™ Sigma Lift" Service and Parts Manual
T - 3 0 8 4 E S
R O U B L E S H O O T I N G
Lower and re-position the machine.
Will receive 4-4 or 7-7 flash on GP400. Clean, service and
charge batteries.
Battery charger may not operate if battery voltage drops
below 20 volts
Check HELP messages using EZ-Cal
Check Speed/Torque Switch at platform controls
Use EZ-Cal to monitor platform state of elevation. See
Diagnostic chart I.D. 2a13 for elevated status and 2e1 for
platform % of elevation input. Failure of the angle transducer
will trigger a fault code.
Located on rear wheel motors only. Check by replacing
valves.
Inspect wheel motors for excessive bypass
Check Speed/Torque Switch
Will receive 4-4 or 7-7 flash on GP400, Clean, service and
charge batteries.
Battery charger may not operate if battery voltage drops
below 20 volts
Inspect wheel motors for excessive bypass
Located on rear wheel motors only. Check electrical by
disconnecting valves or function by replacing valves
Located on top of main hydraulic Manifold
Check with flow meter or replace pump
Check 12 volts to appropriate coil, check coil, check valve
function
Swap counterbalance valves to see if functioning direction
changes.
Scan using EZ-Cal and troubleshooting charts. EZ-cal chart
I.D 4f-7 - Fwd or 2f-9 - Reverse
Check continuity of Speed/Torque switch in platform control
box
Check for 12 volts and ground to valve check for faulty valve
spool
Check or replace valve
These valves should not have 12 volts, in mid-speed, check
valve function
Check continuity through switch
Check continuity of Speed/Torque switch in platform control
box
Check voltage and ground to valve check for faulty valve
spool
Check or replace valve
Remove, clean orifice. See hydraulic diagram for location in
manifold.
Replace brake discs located inside rear wheel motors.
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M O D E L R O U B L E S H O O T I N G
C
H A R T
November 2009
Page 4b-31