Jungheinrich Error Code 1901 [work] Jun 2026

Conclusion

| Common Cause | Detailed Explanation | Solution | | :--- | :--- | :--- | | | The sensor, often a Hall effect sensor, may have failed. Internal drift, cold solder joints, or a broken track can cause it to send a continuous signal. | Inspect the pedal sensor and wiring harness. If faulty, the entire pedal assembly may need replacement. | | ⚠️ Mechanical Obstruction | A physical object (e.g., a floor mat, debris, ice in cold storage) might be pressing against the pedal, or the pedal's pivot could be jammed, preventing full return to the 'zero' position. | Remove any obstruction and ensure the pedal moves freely and springs back to its upright position. | | ⚡ Electrical Issues | A broken wire, loose connector, short to ground, or corrosion in the wiring harness can send a stray 'active' voltage to the controller. | Inspect the wiring harness from the pedal to the main controller for any signs of damage, wear, or loose connections. | | 💻 Controller Malfunction | In rarer cases, the analog-to-digital (A/D) converter input on the main controller responsible for reading the pedal signal could be faulty. | Advanced diagnostics with dealer-level software like Jungheinrich's JUDIT-4 are required to test the controller's inputs. |

Only a dealer or well-equipped technician can perform this step. Connect to the truck’s OBD-style diagnostic port. Jungheinrich Error Code 1901

Always disconnect the battery and follow proper lockout/tagout procedures before inspecting electrical components.

To avoid future 1901 error codes, ensure operators are trained to: Conclusion | Common Cause | Detailed Explanation |

: Dust, debris, or a broken return spring holding the pedal slightly down.

If the error persists after recycling the power without touching the pedal, follow these diagnostic steps: If faulty, the entire pedal assembly may need replacement

Error 1901.1 is part of a series of safety interlocks designed to ensure the operator is seated and ready for safe operation. If you encounter similar codes, they are likely related:

A qualified technician should use a Jungheinrich diagnostic tool to check the "pedal value" in the controller. If the value is not at zero when the pedal is idle, the potentiometer needs adjustment or replacement. 4. Controller Reset Sometimes the error code is "latched" in the memory.

: Turn the key to the "OFF" position, wait a few seconds, and then turn it back to "ON" without touching the pedals.

Connect a voltmeter to the battery terminals.