Before checking components, rule out operator error. Turn off the forklift completely. Remove your foot from all pedals and restart the truck. If the code clears, the issue was just operator timing. 2. Inspect the Pedal Assembly Mechanically Debris often accumulates around forklift floorboards:
| Sub-Code | Meaning | | :--- | :--- | | | Signal voltage too low (sensor short to ground) | | 1901-2 | Signal voltage too high (sensor open circuit or broken wire) |
The machine fails to move when the throttle is engaged.The display alternates between the hour meter and the 1901 code.The lift and lower functions may be disabled.The error may be intermittent, occurring only when the tiller is moved to specific angles. Step-by-Step Troubleshooting Checklist
Before checking components, rule out operator error. Turn off the forklift completely. Remove your foot from all pedals and restart the truck. If the code clears, the issue was just operator timing. 2. Inspect the Pedal Assembly Mechanically Debris often accumulates around forklift floorboards:
| Sub-Code | Meaning | | :--- | :--- | | | Signal voltage too low (sensor short to ground) | | 1901-2 | Signal voltage too high (sensor open circuit or broken wire) | Jungheinrich Error Code 1901
The machine fails to move when the throttle is engaged.The display alternates between the hour meter and the 1901 code.The lift and lower functions may be disabled.The error may be intermittent, occurring only when the tiller is moved to specific angles. Step-by-Step Troubleshooting Checklist Before checking components, rule out operator error