From the book -

HPD: High Pedal Disable - The HPD feature prevents the truck from being started while the throttle is applied. The system is programmed to give the HPD warning if there is a throttle request before a truck ON or brake release signal input.

Bassically your throttle potentiometer is out of range and needs to be replaced/adjusted or your throttle mechanically needs new spring/bushings/handle grips etc..

Code 35 is

Brake Switch Error - Normal travel controls are disabled. the truck will respond only to activations of the emergency reverse switch if the traction motor is rotation in tractor-first direction.

Alarm sounds 3 beeps once the error code is generated.

Reason for this code: The brake switch is out of adjustment or damaged at the same time the traction motor is detected rotating.

Adjust or replace the switch for the brake SW2(deadman). This is the switch that the entire arm actuates when you push the arm down.

Code 30 is

Emergency Reverse Switch has been activated.
Normal travel controls are disabled. The truck will only respond to emergency switch activation.
Alarm sounds 3 beeps when error code is generated.
The reason for this code: The emergency reverse switch has been pressed then released.

Cycle the brake (deadman) switch and engage the brake and this code should clear after cycling the brake.

Code 22 is

ANTI-Tie Down

Travel is limited to coast speed, all other systems perform normally.
Alarm sounds - NO
Reason for this code: Rabbit switch pressed ahead of the brake being released or throttle being applied.

CONFIRM that the rabbit switch is not stuck/shorted out, replace and adjust as neccesary.

Also getting stuck in pallets and whatnot, our trucks here have replaceable plastic "skids" bolted to the tip of the forks. The skid lifts the tip of the fork up as your sliding into the pallet. Also if you have alot of broken pallets or trying to move around empty pallets that have no weight on them you will get stuck regardless of having skids/rollers on the fork tips.

--Cheers