Discussion:
NR3500 Error Help

I have a CAT nr3500 36v reach forklift, when key turned on wont move and cant use hydraulics says "logic fault 62" on the display. Had similar issue before dont remember fault code, the fix then was to have battery reconditioned and voltage monitor installed. forklift worked for couple months now back to an issue, the battery
reads 37.2 volts
  • Posted 14 Nov 2025 06:06
  • Modified 18 Nov 2025 01:39 by poster
  • By MedEngineer
  • joined 14 Nov'25 - 4 messages
  • FL, United States
Showing items 1 - 8 of 8 results.
is this a newer truck? what is the serial number?
i was looking in some of my troubleshooting info i have from back when i worked at cat and for this 36v model it is saying code 62 is an alarm code and is related to the EPS system, saying that at least one of the controller/motor phases are high. If the code is permanent then replace the EPS.
usually the display will display something like "Alarm 62 on Mod6".
I went through the entire code list and the EPS system (mod6) was the only one that had code 62.
this is for the zapi system though and if your truck is newer this may not apply.
  • Posted 11 Dec 2025 15:32
  • By swoop223
  • joined 23 Mar'12 - 3,696 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
Let me know if you had any issues with the files or that you got them
  • Posted 4 Dec 2025 10:40
  • By Rob1708
  • joined 12 Oct'25 - 10 messages
  • Ohio, United States
Check email
  • Posted 4 Dec 2025 03:28
  • By Rob1708
  • joined 12 Oct'25 - 10 messages
  • Ohio, United States
you can email me here, appreciate the help
  • Posted 4 Dec 2025 02:38
  • Modified 4 Dec 2025 03:39 by poster
  • By MedEngineer
  • joined 14 Nov'25 - 4 messages
  • FL, United States
(1) Situation
(2) Possible cause
(4) Checks
Display: "62". All truck operations inhibited. Line contactor OPEN.
Faulty EEPROM data, faulty logic unit.
Set Setup Options. See page 5-3.
Turn off power.
Turn on power.
If fault remains "62"
Disconnect battery plug, then discharge electric charges
from inverters and APS unit.
Replace logic card of logic unit.
(3) How the error code is triggered
ROM SUM value of logic card is different from check data. EEPROM SUM value of logic card is different from check
data. RAM of logic card is faulty.
(5)
(6)
Error code "61"
See troubleshooting for code "61". See page 9-81.
Service codes all 1 and management mode pass all 4

So I'll was thinking of a nrr model here's what I found for code 62 if you got an email I can get you better info
  • Posted 3 Dec 2025 12:27
  • Modified 3 Dec 2025 12:34 by poster
  • By Rob1708
  • joined 12 Oct'25 - 10 messages
  • Ohio, United States
This is picture of the display on the forklift
  • Posted 29 Nov 2025 04:24
  • By MedEngineer
  • joined 14 Nov'25 - 4 messages
  • FL, United States
Serial number is #4NR3936900, also bought this forklift used and am unaware of a hand held controller for it.
  • Posted 29 Nov 2025 04:19
  • Modified 29 Nov 2025 04:32 by poster
  • By MedEngineer
  • joined 14 Nov'25 - 4 messages
  • FL, United States
So logic faults on these start at the Cisco witch is the display is everything starts there see if you can get into the master program to see what's going on if the display unit is messed up then it takes the truck out. Got a serial number I might be able to get a manual if you need it. Should be a zappi hand held to talk to the truck too. Need to know what MOD the code is in. (Also code 62 in mod 6 is VMN NOT OK Alarm 62.In the initial rest state at least one of the phases of the motor voltages are high. If the alarm occurs permanently, the EPS needs to be replaced.)
  • Posted 24 Nov 2025 11:32
  • Modified 24 Nov 2025 11:43 by poster
  • By Rob1708
  • joined 12 Oct'25 - 10 messages
  • Ohio, United States

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