how-to articles Archives

Hyster forklift error codes explained

Yale MPB40-E forklift
Yale MPB40-E forklift

Hyster W40Z forklift
Hyster W40Z forklift

Are the error codes on your Hyster W40Z or Yale MPB40-E pallet jack confusing you? Keep reading to learn what problems these codes indicate and how you can solve them.

Yale dash display Intella Liftparts forklift parts

Q: How do I read Hyster W40Z or Yale MPB40-E pallet jack codes?

A: Hyster and Yale forklifts use the same control system, so error codes on Hyster forklifts are the same as those on Yale forklifts. These error codes can actually appear in many ways. While they can be communicated with flashes of a red LED bulb on the jack’s controller, this blog will cover the error codes presented on the jack’s dash display. Sometimes, an error code can mean one of many potential issues. In these cases, it may be necessary to use a special handset or PC to determine which of the problems is the cause of the error code.

Having trouble with error codes from another brand? Check out these other helpful links:

Below are interpretations for the following error codes: no LEDs, no alarm, AL66, AL99, AL01, AL02, AL4, AL5, AL6, AL7, AL8, AL10, and AL94.

Let us help you find your code
  • Dash display: no LEDs or LCDs on
    Condition: inoperative
    Cause: B+ and/or B- missing at controller, defective battery charger, or defective battery charger
    Solution: make sure 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
  • Dash display: no LEDs or LCDs on
    Condition: forklift functions as normal
    Cause:  open connection between display and controller, defective display, or defective LEDs
    Solution: 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
  • Dash display: no LEDs or LCDs on
    Condition: forklift functions as normal
    Cause:  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.
    Solution: replace controller
  • Dash display: no alarm
    Condition:  traction and hydraulic functions not working
    Cause: improper startup sequence by jack operator
    Solution: check brake switch, accelerator, steer handle, and hydraulic inputs
  • Dash display: AL66
    Condition: hydraulic function not working
    Cause: battery voltage is low or controller voltage calibration is incorrect
    Solution: 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
  • Dash display: AL99
    Condition: traction and hydraulic functions not working
    Cause: incorrect battery selected, damaged battery, or damaged connection to batter
    Solution: 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
  • Dash display: AL01
    Condition:  traction and hoist functions not working
    Cause: control card throttle or lift/lower calibration is out of range; control card is damaged or defective
    Solution: 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
  • Dash display: AL01
    Condition: traction and hoist functions not working
    Cause: incomplete connection between control card and controller; traction reversing switch not connected; damaged or defective tiller card
    Solution: 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
  • Dash display: AL02
    Condition: traction and hydraulic functions not working
    Cause: main contactor tips are welded closed or motor field circuit is broken
    Solution: disconnect power leads at contactor and test for an open circuit; check connections between motor field and controller
  • Dash display: AL4
    Condition: traction and hydraulic functions not working
    Cause: damaged connection to lowering valve; damaged lowering coil or lowering valve cartridge
    Solution: 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
  • Dash display: AL5
    Condition: traction and hydraulic functions not working
    Cause: damaged connection to brake or brake coil damaged
    Solution: 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
  • Dash display: AL6
    Condition: traction and hydraulic functions not working
    Cause: 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
    Solution: 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
  • Dash display: AL7
    Condition: traction functions reduced below 14°F or above 167°F and not working above 194°F
    Cause: controller temperature is too hot or cold; controller temperature is not calibrated correctly; controller sensor or controller itself is damaged
    Solution: move truck to a warmer or cooler location; use a handset to check that controller temperature matches room temperature (if not, replace controller)
  • Dash display: AL8
    Condition: traction and hydraulic functions not working
    Cause: over current in driven component
    Solution: 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)
  • Dash display: AL10
    Condition: traction and hydraulic functions not working
    Cause: 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
    Solution: 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-)
  • Dash display: AL94
    Condition: traction and hydraulic functions not working for one minute
    Cause: no fault is occurring – the controller is installing hour meter memory from MDI display if controller has been replaced
    Solution: no solution needed; truck will operate as soon as data transfer is complete

Looking for Hyster forklift parts? Intella can help. We have thousands of parts available at great prices and would be happy to help you find what you’re looking for.  Click here for more information!

Also you can check out Intella’s YouTube channel for how-to videos and product demos.

Post by Intella Liftparts

How to view a Hyster or Yale forklift hour meter

Want to view the hour meter on your Hyster or Yale forklift? Just follow the instructions below.Hyster Yale forklift dash display Intella Liftparts

Step 1: enter the Set-Up and Diagnostic Menu

•  Turn the ignition key to the on position.

•  Press the star button (*) three times. This button is located on the right-hand side of the display.

•  Enter the service password and press the star button (*).

•  Now that you’re in the service menu, press the 4 or 5 button to go back 1 level if need be. These buttons are located on the right-hand side of the display as well, and they likely have arrows on them like in the picture above.

•  Press the star button (*) to show “Main Menu – Passwords.”

•  Use the 4 or 5 button to scroll through the menu items. The star button (*) selects a sub-menu item.


Step 2: view the hour meter

•  Use the star button (*) to select “Hour Meters.”

•  A list of hours should be shown. These include engine, system, hydraulic, and starter hours.


This information applies to Hyster FT series models (like H50FT or S50FT) and Yale VX series models (like Yale GLC050VX or GLP050VX).

Post by Intella Liftparts

How-to forklift videos!

You’ve probably been there before. You find a problem with your forklift, figure out the right solution, buy the necessary parts, and then… have to call in help to do the repairs. With Intella Liftparts, our goal is your independence: we’ve helped you with the parts, now let us help with everything else.

With that said, check out our library of original how-to videos for forklift repairs of all kinds. Our videos focus on the most common problems that forklifts can have, ensuring that assistance for you is as available as possible. Check out the list below for more details.

how-to forklift videos Intella Liftparts
Head over there! Just click the image.

Intella Liftparts forklift repair tutorials:

•  Problems with your pallet jack? How to replace a pallet jack load wheel and riser assembly right here.

•  Need help rebuilding your Impco VFF-30 fuel lockoff? Got you covered.

•  What about an Impco model J regulator? Yup. Rebuilding that too.

•  Just keep rebuilding with this Aisan forklift fuel regulator rebuild.

•  To prevent forklift breaks, make sure your forklifts are operating safely with this tutorial on how to fix forklift brakes.

•  Keep your operators comfortable by watching how to properly replace a Toyota forklift seat.

•  New propane tank? Here’s how to replace the old one.

•  Have you been smelling propane gas around your forklift lately? Don’t worry: your forklift probably isn’t leaky, and it doesn’t need to be serviced. Its propane tank simply needs new O-rings. Check out how to replace these rings here.

Post by Intella Liftparts

How to change a Hyster or Yale forklift password

Looking to change the password on your Hyster or Yale forklift? Just follow the instructions below to change your forklift password.  Need Hyster forklift parts?  Click hereHyster Yale forklift password dash display Intella Liftparts

Step 1: enter the Set-Up and Diagnostic Menu

•  Turn the ignition key to the on position.

•  Press the star button (*) three times. The star button is located on the right-hand side of the display.

•  Enter the forklift password and press the star button (*). 

•  Now that you’re in the service menu, press the 4 or 5 button to go back 1 level if need be. These buttons are located on the right-hand side of the display as well, and they likely have arrows on them like in the picture above.

•  Press the star button (*) to show “Main Menu – Passwords.”

•  Use the 4 or 5 button to scroll through the menu items. The star button (*) selects a sub-menu item.

Step 2: edit your forklift password

•  Use the star button (*) to select “Passwords.”

•  Enter your password.

•  Use the 4 or 5 button to scroll to “Edit Password” and select it with the star button (*).

•  Enter your password again.

•  Under “Password Type,” enter your new password.

•  Use the star button (*) to select “Save and Exit.”

SIS forklift radar

Post by Intella Liftparts

How to locate and read a GM forklift engine serial number

Step 1: Locate the number on the engine block

The serial number of your GM forklift engine will be in a location specific to your model of engine. Below are diagrams showing locations for 2.5/3.0L L-4, 4.3L V-6, small block V-8, and big block V-8 engines, respectively. The big block V-8 engine has two diagrams, indicating serial number location for models both before and after 1991.

We sell new GM 4.3 and GM 2.4 liter engines for forklift applications!

2.5/3.0 L L-4 engine
2.5/3.0L L-4 engine

4.3L V-6 engine
4.3L V-6 engine

small block V-8 engine
small block V-8 engine

big block V-8 engine, pre-1991
big block V-8 engine, pre-1991

big block V-8 engine, 1991 and on
big block V-8 engine, 1991 and on

Step 2: Interpret the number

Once you have located the serial number, you can derive from it information about your forklift engine. As shown in the diagram below, the first letter indicates the source code of the product. The next four digits indicate the month and day the engine was produced, and the last three digits are the engine’s type code.

interpreting your serial number
interpreting your serial number

More about GM engines

A variety of forklift manufacturers have used GM engines in the past.

Hyster‘s history with GM engines goes back many years, all the way back to the 2.4 liter engine as well as the 3.0 “iron duke”, and the 350/4.3 engine.  When the parent company of Yale, “Nacco” purchased Hyster Company, Yale began using GM engines as well.  Recently Nacco has moved away from GM engines to Kubota.

Toyota uses GM engines as well, believe it or not.  The automotive rivals work together somehow as Toyota uses the 4.3L engine.  Toyota did use the 3.0 liter engine for a brief period but it no longer does so in 2015.

Mitsubishi/Caterpillar Forklift uses the GM 4.3 engine in its 8000-12000 pound capacity lift trucks.

SIS forklift radar

Looking for parts for GM engines used in forklifts?  Intella can help.  We carry tune up parts, cooling / water pumps, starters, alternators, distributors, filters, and general rebuild parts.  We know GM engines and we can help you determine what you need.  If you can’t figure out from our website what you need to order, please call us at 616-796-1288.

Post by Intella Liftparts

Hyster and Yale IFAK Diagnostic Tool

Ifak for Nacco forklifts. Aftermarket parts by Intella LiftpartsYou’ve watched the technician from the Hyster or Yale dealership using his laptop computer and the Ifak cable to diagnose and program your forklift. Pretty cool, right? So how does this help him repair your forklift?

The software reads the on-board diagnostics built into your forklift. It contains a database of all of the possible diagnostics codes in the system and the associated troubleshooting guides. The tools included allow the technician to test individual components right from the computer screen without opening his toolbox. He can also make adjustments to your forklift’s transmission, speed control, operator access, impact monitors and many others. He can look at temperatures and operation history and current status. All of this helps your technician to diagnose and repair your forklift in short order.

Now you want to know where you can get the software and IFAK interface cable. Sorry, they’re not available for sale anywhere we’ve found.  Even if you could purchase one, you wouldn’t have access to the Hyster/Yale website that the dealers use with their laptops.

Ifak for Hyster Yale forklifts. Aftermarket parts by Intella Liftparts

Nacco (the parent company for Hyster and Yale) will only allow access to their software to fully trained and certified technicians that work for their dealerships. It is easy to explain when you understand what is at stake.

The adjustments available to the technician are very complicated and take a great deal of training to understand how to correctly calibrate and adjust your forklift. There are also some options available that are activated through software and must be purchased through your dealer. Nacco technicians are required to take hundreds of hours of factory training to become certified with their software. If an untrained person were to make certain adjustments it could cause an unsafe condition.

The liability for the dealer and the manufacturer would be enormous.

All is not lost. The forklifts built today give the technician or customer access to much of these diagnostics tools through a menu system on the dash. You can access most of the diagnostics codes and make limited adjustments right from the dash display.   Often many dealers technicians don’t even use the IFAK cable–they simply look at the code displayed on the dash.

It is important to remember that many mechanical problems can be diagnosed and repaired in the same way as in the past. Forklifts are still basic machines that have become safer and more efficient thanks to technology.

SIS forklift radar

Post by Intella Liftparts

Inspecting Impco Systems for High CO Levels

Step 1: Squeeze Hose

Impco VFF30 emissions
Impco VFF30 emissions

Use a needle-nose pliers to pinch the vacuum hose on the VFF-30. If the RPM speed changes, the o-ring seal is bad. If after disconnecting the hose the engine doesn’t die or the o-ring is bad, the Impco VFF-30 needs to be replaced or rebuilt. You can also test this using carbon monoxide readings.

*If you have an electric lockoff in your lift truck, you will also have a vacuum safety or an oil pressure switch. It is against regulations for these to be disconnected (see NFPA Pamphlet 58).

Impco VFF30 exploded view
Impco VFF30 exploded view

Step 2: Prime

impco model J
primer button model J

Push the primer button while the engine is running on the Model J vaporizer-regulator. IMPCO no longer manufacturers a model J with a primer button.  However, primer buttons are available on Impco model J generic units which we offer.  The engine should stall or completely shut off while pushing the button and start back up to idle as soon as you release. If this doesn’t happen or pushing the button causes the engine to speed up, adjustments are needed with the air-fuel mixture in the mixer.  To watch how a Impco model J is rebuilt, check out this video here.  A video on how to rebuild an Impco VFF30 can be found here.

Impco CA55 carburetorStep 3: Air-Fuel Ratio Adjustments

Turn the idle mixture screw (on the mixer) counterclockwise as far as possible. The emissions reading should decrease in carbon monoxide. 


CA100 Impco carb mixture screwStep 4: Air Filter

Take out the air filter and inspect it. Replace the filter if there is an increase or decrease in emissions after the air filter is removed.

Step 5: Mixer

If you haven’t had any problems with anything in steps 1-4 and CO levels are still too high, the mixer must be replaced. Usually, you can replace your Impco Model 50 carburetor/mixer with a new Impco Model 100 or 125 with minimal adaptations. If this is not the case for you, go with a Model 55.

Step 6: Air Valve

There are 4 screws holding the Impco Model CA100/125 mixer cover that need to be removed in order to check out the air valve. (It should be part AV1-14-4; if not, replace with the correct part.) Make sure the metering cone is clean on the inside and there are no signs of wear. If you see marks implying the valve is rubbing, either sand the guide gently or replace the air valve. A lean air shim or 2 may be installed at this point if the fuel mixture still isn’t right.  Install the first shim on the metering cone lip and check the emission levels; if only a minor improvement, add the second shim.

*Clean the air valve with a solvent solution. Do not wash the diaphragm or use an abrasive cleaner on any parts. Make sure the gas valve cone is tight in the body housing.

Step 7: Power Mixture Setting

Emissions should be at an acceptable level when the truck is idling. Set the power mixture and load the mast by tilting completely back or forward. If you have a rich condition based on the exhaust analyzer, turn the power valve, or gate valve as its also known, to the “L” position.

desired emission readings_Intella Liftparts

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Forklift Air Filter Storage and Handling Tips

Getting the most life out of your forklift air filter is important. This starts with storage and handling. Before you even start the installation process, make sure the new filter is less than 6 years old (based on the manufacturing date) AND it is clean/undamaged. Here are a few more quick tips to help with your forklift air filter storage:

Air filter forklift filter

1)  Make sure to always store air filters in a box, not out on a shelf where they can pick up dust in the air.


2)  If the box isn’t sealed tight, tape it shut.


3)  Individually wrapped


4)   When transporting air filters, make sure they aren’t rolling around. Throwing them in the back of the truck or the floor boards could cause damage.


5)   Don’t store the filters on anything metal. Metal condensates and could cause rust on the filter. Boxes are best.


6) Just like with food, put the oldest filters in the front. Make sure you put new stock in the back so you don’t end up with expired filters. (Remember, 6 years from the manufacturing date is the oldest you want to use.)


7) Make life easiest by ensuring labels with product information and manufacturing dates are visible.


8) Don’t store filters in extreme temperatures or excess moisture. The environment you store your filters in will effect their shelf life.


9) When installing or just handling new filters, make sure your hands are clean. Avoid contact with the outlet side of the filter if possible.



Intella has a complete line of forklift filters.  We carry filters for most brands of forklifts including Hyster, Yale, Toyota, Cat, Kalmar, Taylor Forklift, Nissan Forklift, Komatsu Forklift and most others.


Post by Intella Liftparts

Servicing Forklift Air Filters using restriction indicators

Forklift mechanic changing forklift air filter
Forklift mechanic changing forklift air filter

Servicing a forklift air filter by restriction is the best way to get the most life out of your filter. Proper servicing can save you money and time. Dirty filters do not always mean they are trash. Many times, dirty filters can  go more hours!

Mechanic measuring the restriction to determine if there is a plug in the system
Forklift mechanic measuring the restriction to determine if there is a plug in the system

Don’t want to cause a problem in your air cleaner? Don’t service it too much. The elements in the filters are more efficient as dust builds up on the media. But  avoid dust and other abrasive particles when removing the filter!

There are a variety of choices when it comes to measurement tools to get the most out of your filter.

Restriction measurement tool options
Restriction measurement tool options

Looking for a continuous reading device to see how much life is left in that old filter? Check out The Informer and the Service Gauge for Instrument Panel.

Intella has a complete line of forklift filters for sale.  Easy online ordering allows you to quickly select the filter you need–at a great price!

Post by Intella Liftparts

Forklift Air Filter Tips and Maintenance

Donaldson airfilterRegular maintenance is crucial to the life of your forklift air filter.  Inlet hoods must not be missing and all openings and tubes must be clear. Dented or damaged units and housings must be fixed or replaced to optimize operations. Make sure there are no leaks in the ducting to provide particles a trail straight to the engine.


filter2Cleanliness of the filter is not a sign of life or death. Clean filters can have dirt and carbon deep down in the filter; dirty looking filters may still be working great. Filters are a low-cost investment to keeping things running smooth.


Capture3Keep air cleaners closed as much as possible! If there is no filter, there is no barrier between the engine and the outside world. Protect the engine during filter changes by keeping the opening covered. Just because you can’t see the dirt and particles doesn’t mean they won’t affect the engine.


Capture4Gaskets that are damaged should be replaced when changing forklift air filters. Be sure to check service instructions on if gaskets need to be replaced at each filter change and don’t use an old one you have laying around. (This is usually the case in EBA and ERA model air cleaners.)



When changing out lift truck filters make sure to use the same Capture8part number. Filters may look the same but they provide different seals that can affect airflow and can cause serious damage over time. The only time you should change model numbers is when there is an upgrade to an older style.


Forklift manufacturers give you recommendations on the roCapture6utine you should follow regarding maintenance of your filters. Each new filter has a different set of recommendations and guidelines. Make sure you are up to date with the newest procedures. Keeping records and following these guidelines are necessary in the likelihood you need to use a warranty claim. It is often helpful to record the filter changes right on the filter itself. It doesn’t matter if you track it by miles or hours, just keep it consistent.


Dirty forklift filters can contaminate clean filters during a routine service change. Make sure to wash your hands or remove your gloves after handling the dirty filter and before coming in contact with the new one. It is also helpful to keep the new filter in the box until you are 100% ready to install it.


Tightening and inspecting the forklift air cleaner system  connections is the last step. Make sure everything is free of holes and damage; worn spots and damage especially to the elbows, seals and connections must be checked thoroughly. Tighten all clamps and inspect pre-cleaners and inlet hoods. Reset manual filter indicators and make sure to record any and all action you have performed.

Post by Intella Liftparts