I am assuming you have knowledge in electric forklift repair. If you have zero experience with one of these, i highly suggest to call your local Unicarrier dealer. If feeling a little spunky, then i would first off make use of a camera and take pics of what you are about to disaasemble. Locate a static strap ( If needing to know how to use static strap, just walk away and call your local Unicarrier dealer)before proceeding in removing the print card from unit. Disconnect battery and remove all connectors from the metal print board box. Remove card and metal housing. Carefully inspect the bus bars for any overheating and possible wire melted to them especially around the PS contactor. If all looks good then check upper right hand of the the control panel. There you will see 8 wires from 2 transistors that plugs into the upper right hand corner of the main print card. These are the IGBT's for the steering. The 530 code shows that there is a short in the PS circuit thus the inspect for melted wires. I rather see an open code ( 531 ) than the 530 short code. You can remove the cover to expose the main print card. Look upper right hand corner of card where the 8 wires comes together in a plug and is inserted into the main print card. With a mag glass, look for any small components that has blown out ( small chips ) on the card. If any are found blown then you will need a new or refurbished main print card, new set of igbt's and a ps motor check. Order the igbt's in a set from Unicarrier dealer. The reason is they are matched for same resistance reading. The ps current sensor is basically a resistor that is ceramic and is located beneath the ps contactor and it will have the Ohms value printed on it. If uncomfortable with or have never trouble shot a system as this, i would suggest calling a dealer. These parts are expensive and little wisps of smoke out of the main print board can mean over a grand in cost for a new one. The IGBT's can be costly also. Been awhile since i have worked on one of these trucks as many are being replaced by newer models. Hope this helps.