Komatsu FG25T-16:
Seat switch not recognized

FG25T-16, SN 210328A
Background: Seat switch not being recognized, lift/tilt lock solenoids not receiving power. Prior to service call, customer had replaced seat switch, switch harness, main harness, OPSS unit, and lift/tilt lock solenoids.

Currently: No Neutral light on dash. MIL flashing 4 times. Check engine illuminated. OPSS light flashing. Seat switch receiving power and working properly. Unit will travel forward and reverse, backup alarm sounds. Unit will lift/lower but tilt is still locked out with power directly supplied to solenoids. All fuses checked, relays checked, no issues. Harness checked, no damage or loose connections.

Suggestions?
  • Posted 4 Nov 2021 03:09
  • Discussion started by James_D71
  • Oklahoma, United States
Showing items 1 - 2 of 2 results.
I've had this problem several times. There was a wire going into the bottom of the relay box in left side under seat in engine compartment that had backed out. The connector pin kept backing out. I cannot remember what number it was but you should be able to find the seat switch relay and figure out where the connectors are.
  • Posted 19 Nov 2021 16:33
  • Reply by 1CrownTech
  • Washington, United States
1crowntechnician@gmail.com
Hello James,
I think it's a wiring problem, we had the same problem in the past. The wiring (several wires that are connected to each other) that runs to the OPSS had come loose, you can only see this if you loosen the protection. If I'm not mistaken, it was the wiring on the left side between the transmission and the engine. If I'm not mistaken, it was the wiring on the left side between the transmission and the engine. Our machine was a European version so I'm not sure if an American version has the same wiring.
Good luck
Marcb
  • Posted 5 Nov 2021 03:03
  • Reply by marcb
  • ANTWERP, Belgium

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