Jungheinrich Error Code 1901

An unsecured floor mat, a piece of shrink wrap, or debris is jammed underneath or around the pedal, holding it down.

* 1901.1 – Drive pedal activated during startup. * 2951.1 – Hydraulic function activated during startup. Machine Maxx USA Jungheinrich Forklift Truck Fault Codes DTC.pdf

: Check for debris, dirt, or floor mat interference that might be physically holding the pedal down.

⚠️ Always disconnect the battery before unplugging controllers. Capacitors in the drive controller can hold dangerous voltage for up to 5 minutes after key-off. Jungheinrich Error Code 1901

This is the most likely cause and the simplest fix.

: The neutral zone or "window" for the pedal may need to be widened or recalibrated by a technician.

Jungheinrich error code 1901, CAN bus timeout, drive controller fault, Jungheinrich troubleshooting, forklift error 1901 reset. An unsecured floor mat, a piece of shrink

If your unit uses a potentiometer, it may have drifted out of the zero-travel calibration. A certified technician will need to use the Jungheinrich Diagnostics Tool to verify the sensor's voltage values.

Inspect the wiring harness leading from the drive pedal potentiometer/microswitch to the main controller. Look for signs of wire breakage, pinching, or corrosion.

Seat belt or belt lock not closed when the pedal is pressed. Machine Maxx USA Jungheinrich Forklift Truck Fault Codes DTC

Before any inspection or repair, ensure the forklift is parked on a level surface, the key is OFF, the parking brake is engaged, and the battery is disconnected (or the main disconnect switch is open). Wear insulated gloves and safety glasses.

Activation of drive pedal when the parking brake is not released. Conclusion

If the error persists even when your foot is off the pedal, there may be a technical issue:

Expected values (NTC thermistor):