Unicarriers (& Nissan) BX50:
problems starting up - error code 23

I have 3 of these forklifts (identical).

One had problems with the crankshaft sensor and showed an error code but started and run fine,
I changed the crankshaft and the camshaft sensors and also changed the spark plugs, and made a tune up. When I try to start it, error 23
shows up and won't start. it fires up and shuts down. I got it started with carburator fluid and started up fine and without error codes, the
next morning, same thing, it fires up but doesn't start.
I start looking for problems, check harness wires and connections... everything is fine.
Until I switch the throttle body, the fuel pump and the oxygen sensor, etc.. with the other forklift's (the one that worked perfectly fine)
and now none of them work now - and both show error code 23 -. The first forklift still won't start and the second one starts but idle wont go up.
I switch the parts back, and the forklift that was working before, works fine but now shows error code 23 too and the First forklift still won't
start up.

Is it possible that both throttle bodies are damage but behave differently on each forklift?

The LPG converters are both new.

I don't understand why is not starting up.

This is my first post here but i always get useful information from this forum and that's why I decided to post my question here.

Thanks.
  • Posted 19 Mar 2014 08:04
  • Discussion started by rushdie_r
  • Ontario, Canada
Showing items 1 - 6 of 6 results.
I agree w RCAV8TOR, the throttle body is high dollar. before I suggested anyone spend that sort of money on a part, I would want to be sure I had checked with an ohm meter the wire harness from pin to pin, between the ECM and the throttle body.
I have seen more of these codes from damage internal to the ECM (battery acid dripped down into the connector and corrosion ate away the metal just on the inside of the ECM pin) rather than the throttle body go bad. And far more failures from wire connection failures than all other reasons, combined.
I think this might be one spot I would be inclined to get the laptop and someone that knew the software well enough to read if the ECM inputs, and see if there are any inputs to the ECM from the throttle body.
How quickly did the code return after you "cleared" it?
if it was 'active', you never would have cleared it for long enough to restart the motor or recognize it was cleared.
  • Posted 19 Mar 2014 20:19
  • Modified 19 Mar 2014 20:55 by poster
  • Reply by edward_t
  • South Carolina, United States
"it's not rocket surgery"
I think i would remove the connectors from the ecm and check for corrosion and also check the relays in the box next to fuse box. You can use the relay marked fuel pump as it is a spare if the truck is an LPG unit. Be sure you verified that all fuses are good and of specified amperage as notated on fuse block cover. ETC is an expensive item.
  • Posted 19 Mar 2014 10:15
  • Modified 19 Mar 2014 10:16 by poster
  • Reply by RCAV8TOR
  • Alabama, United States
What i used to do all day now takes me all day to do.
The serial number I think it's PL029H2420.
motor k25l

And yes, I cleared the codes and also checked everything with the battery disconnected and even opened the wire harness to search for damages and didn't find anything wrong. Same with the plugs that are all fine.

Would getting a new throttle body be a good idea?

Thanks for the answers.
  • Posted 19 Mar 2014 10:05
  • Reply by rushdie_r
  • Ontario, Canada
I second that suggestion edward
  • Posted 19 Mar 2014 09:36
  • Reply by RCAV8TOR
  • Alabama, United States
What i used to do all day now takes me all day to do.
have you cleared the codes with the pedal dance, yet?
stop checking and disconnecting wires while the ignition key is turned on, disconnect the negative battery cable, from the battery before you work on the motor. you set these codes when you disconnected the wires with key switch on, or you have pulled the wires out of their housing when you disconnected them. in any case, clear the codes, then see how quick they return.
  • Posted 19 Mar 2014 09:29
  • Reply by edward_t
  • South Carolina, United States
"it's not rocket surgery"
BX50 is an electric unit. You must have North America designated L0 or 1F series trucks. Please post correct model number.
  • Posted 19 Mar 2014 09:12
  • Modified 19 Mar 2014 09:15 by poster
  • Reply by RCAV8TOR
  • Alabama, United States
What i used to do all day now takes me all day to do.

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edition #1228 - 1 May 2025
There is simply no ignoring the push for a greener, more sustainable materials handling equipment industry as manufacturers and customers alike seek eco-friendly solutions to reduce or eliminate carbon emissions... Continue reading
Movers & Shakers
Linda Häkkilä Linda Häkkilä
vice president, Investor Relations, Konecranes
vice president operations, Elokon Group
President, EP Equipment Europe
Senior vice president human resources, Kalmar