Last update. Fixed the problem with codes 52 and 53. I look at the wires near the speed sensors and near the logic. I assumed it was a wiring problem because the chances of both sensors going bad at the same time are pretty slim. No damage to the sensors or wires near the connectors. Hmmm. Wait, let's check continuity. I know wires don't usually break in the middle of a run, but let's check. No continuity. Tugged on one end of the harness and it came out in my hand. Turns out the driver installed the battery and smashed the harness. Remove battery, fix wires, back in service! Thanks for the help, guys.
Mike

Last update. Fixed the problem with codes 52 and 53. I look at the wires near the speed sensors and near the logic. I assumed it was a wiring problem because the chances of both sensors going bad at the same time are pretty slim. No damage to the sensors or wires near the connectors. Hmmm. Wait, let's check continuity. I know wires don't usually break in the middle of a run, but let's check. No continuity. Tugged on one end of the harness and it came out in my hand. Turns out the driver installed the battery and smashed the harness. Remove battery, fix wires, back in service! Thanks for the help, guys.
Mike

Another update concerning the forklift with code 17. I swapped the logic from a good truck with no success. I did find out that the fault only shows up when going in reverse. Is that helpful? Also swoop I talked to my boss about getting a service manual for that truck.

Their is only a temp sensor in motor which would not be affected by oil and would not bring up 52 53 would be worth cleaning out motors though.if you dont want to go through h bridge test and you have another truck try board in good truck try it with drive board

Ok, so I'm back out here and have another question regarding the codes 52 and 53. Hydraulic oil was spilled onto the drive motors from a broken tube. Is it possible the sensors could have been damaged by the oil? Maybe they can be cleaned?

Save yourself alot of headaches and get a service and parts manual, your going to need it if you have several of these at the customer site.

As for the hbridge card it is mounted underneath the logic card along with a power distribution board. I dont have a manual in front of me at the moment but later on i can take a look and tell you which board is which and possibly how to check them.

This may sound like a stupid question, but I'm not familiar with these trucks at all. What is the h bridge? Where's it located and how can I test it? I work for a Hyster dealership and we just got this customer with a bunch of Cats.
Mike

code 17
Faulty right motor field circuit (wire breakage, shorting), or faulty logic card.
could be a bad H Bridge or faulty logic.

code 52 and 53 are for faulty speed sensor circuits
could be faulty sensors or a bad logic.

check the wiring at the sensors at the drive motors for damage.