Yale and Hyster Pallet Jack Error Codes

Error Codes for Hyster W40Z or Yale MPB40-E pallet jack

Error: no LEDs or LCDs on

What the issue is: Inoperative
Cause of Problem: B+ and/or B- missing at controller, defective battery charger, or defective battery charger
What to do: Ensure the battery is connected, the key switch is on, and the brake override circuit is in the run position; also test your battery charger and motor controller and replace any nonworking parts

Error: no LEDs or LCDs on

What the issue is: Forklift functions as normal
Cause of Problem: open connection between display and controller, defective display, or defective LEDs
What to do: make sure harnesses are connected at MDI and connector B on controller; test the dash display by connecting a handset to it and testing for communication; test LEDs by disconnecting them, connecting the handset, and testing the handset; replace any nonworking parts

Error: no LEDs or LCDs on

What the issue is:  Forklift functions as normal
Cause of Problem: Because this condition is similar to the last, it will take a handset to determine its cause. If the handset displays “NO COMMUNICATION,” the controller is defective.
What to do: replace controller

Error: no alarm

What the issue is: Traction and hydraulic functions not working
Cause of Problem: improper startup sequence by jack operator
What to do: check brake switch, accelerator, steer handle, and hydraulic inputs

Error: AL66

What the issue is: Hydraulic function not working
Cause of Problem: battery voltage is low or controller voltage calibration is incorrect
What to do: Charge or replace battery; otherwise, use handset to determine the voltage read by the controller and compare it to an actual voltmeter reading; replace controller if the two readings differ by more than 1.5 volts

Error: AL99

What the issue is: Traction and hydraulic functions not working
Cause of Problem: incorrect battery selected, damaged battery, or damaged connection to batter
What to do: check that you have the right voltage for your truck, manually check the voltage of your battery, inspect it for any damage, and check its connecting crimps and cables for damage as well

Error: AL01

What the issue is: Traction and hoist functions not working
Cause of Problem: control card throttle or lift/lower calibration is out of range; control card is damaged or defective
What to do: Use the tester function on a handset to see if either calibration is greater than 1 volt at neutral; replace control card if damaged or defective, which can be checked by seeing if both “forward switch” and “backward switch” are on at the same time when testing

Error: AL01

What the issue is: Traction and hoist functions not working
Cause of Problem: incomplete connection between control card and controller; traction reversing switch not connected; damaged or defective tiller card
What to do: Check connections between control card and controller; use a handset to test for operation of traction reversing switch; replace control card if tiller card is damaged

Error: AL02

What the issue is:  Traction and hydraulic functions not working
Cause of Problem: main contactor tips are welded closed or motor field circuit is broken
What to do: disconnect power leads at contactor and test for an open circuit; check connections between motor field and controller

Error: AL4

What the issue is: traction and hydraulic functions not working
Cause of Problem: damaged connection to lowering valve; damaged lowering coil or lowering valve cartridge
What to do: check electrical connection between valve coil and controller; check lowering valve coil for resistance, replace if not approximately 17.7 ohms; replace lowering valve cartridge if necessary

Error: AL5

What the issue is: traction and hydraulic functions not working
Cause: damaged connection to brake or brake coil damaged
What to do: check connection between electric brake and controller; check brake coil for resistance in both directions and replace if not between 27.36 and 30.24 ohms

Error: AL6

What the issue is: Traction and hydraulic functions not working
Cause of Problem: Damaged connection to traction motor; traction motor armature resistance is too low; field wires are loose or damaged; motor field winding is shorted or too low.
What to Do: Check electrical connection between traction motor, field wires, and controller; check traction motor armature for shorts; check motor field resistance and correct if not between 0.5 and 1.5 ohms; check contactor coil for resistance of 52 ohms

Error: AL7

What the issue is: traction functions reduced below 14°F or above 167°F and not working above 194°F
Cause of Problem: controller temperature is too hot or cold; controller temperature is not calibrated correctly; controller sensor or controller itself is damaged
What to do: move truck to a warmer or cooler location; use a handset to check that controller temperature matches room temperature (if not, replace controller)

Error: AL8

What the issue is: traction and hydraulic functions not working
Cause of Problem: over current in driven component
What to do: check main harness for damaged connections to main contactor, brake, and electric valve coils; check contactor, brake, and electric valve coils for correct resistance (52 ohms for contactor, between 27.36 and 30.24 ohms for brake coil, and 17.7 ohms for electric valve coils)

Error: AL10

What the issue is: Traction and hydraulic functions not working
Cause of Problem: controller is damaged; damaged wire connection; short circuit in harness; ground between motor windings and chassis; motor field winding is shorted to chassis; field current driver circuit has failed; watchdog hardware circuit is damaged
What to do: Cycle key switch off and on and replace controller if problem not solved; check wire connections at contactor, pump motor, and traction motor; check main harness for shorts; check for grounds or shorts between motor windings and chassis; check motor field resistance (should be about 1.5 ohms); measure voltage between F1 and B- and F2 and B- on field current driver (should be half the voltage between B+ and B-)

Error: AL94

What the issue is: Traction and hydraulic functions not working for one minute.
Cause of Problem: No fault is occurring. The controller is installing hour meter memory from MDI display if controller has been replaced.
What to do:  No solution necessary. Fork truck will operate as soon as data transfer is complete.

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