I know this post is old, but would you be able to get me any info on this?

Just to let everyone know.....there was an update to fix code 51 on Cat and mitsu 3 wheelers......the pot has a switch inside also...basically an accel switch...the update is to weld a plate to the underside of the floorboard, and install an external accel switch....really quick job and cures most of the code 51 failures.....you also modify the harness going to the pot

Accel fault struggled at customer once and found wire at plug in Logic board it was the wire from the accel pedal I forget what colour it was bur=t if you wiggled it it would cause the code 51. I just bent the pin in the logic board a bit to make a tighter fit...I hope it helps... Still check to accel pot first and the wiring.

This code is common. What gets me is the pot (same one in a toyota car) has a switch and pot. 2 wires for "on" switch are supposed to be 3 ohms new..but often the best you get is 20 ohms. When code appears, the resistance of the "on" swith is 75 or more ohms. Also, the wiper resistance does not sweep smoothly when bad...it jumps with the fluke meter needle. Some switches are bad right off the bat! Using 100 psi to blow the machine does not help them. Plugs are a problem too...female pins spead their legs...and that could be trouble...;)

Yes Daniel, Error 51 is not correct offset accelerator.
In my forklift park (2 EP16K and 2 EP20K) two time i have this error.
One time i have remplaced this part , one time i have adjusting offset.
Check the offset before the remplacement accelerator.

Also overlooked here is to use self diagnostics to determine that the ON/OFF switch is activated before the display starts to indicate the 0-15 position steps.

As Hans says the accelerator pot is very reliable and in our expierience error code 51 can be solved by simply rotating the pot on the adjustment slots.

dear all,

just been set up as forum user.
Here my point of view on this subject.
Like Etharp stated, is could be related to the accelerator itself. Would like to add some to this. This (Janpanese manufactured) accelerator was introduced in 1996 and proven to be a very reliable component. What has been seen in the field is that a pin in the 4-pin connector of the main harness connection to this accelerator could be pushed back in the connector. Mechanics tend to pull the wire to disconnect this accelerator when removing the floorplate since this is a very tight fit connectorand resulting in intermitting contact. During operating the truck it could generate the code 51. Truck stops, recycle the key-switch and drive off again.

Secondly, the yellow multi pin connector in the main truck logic card (located on top of the control panel in the counterweight) is often pulled out by depressing the mini lock pin and pulling the wires! Also a reason for a pin being pulled out of the connector making intermitting contact.

Hope this helps.
Regards, Hans.