You will need:
The specific feature triggered by this code is the truck’s decentralized electronic architecture—where multiple controllers (for driving, lifting, steering) talk to each other via a data bus instead of individual wiring.
What happens when Code 1901 is active:
Most common causes (not a feature, but diagnostics):
Jungheinrich Error Code 1901, like any machine fault, requires prompt attention to ensure the continued safe and efficient operation of the equipment. By understanding the potential causes, recognizing the symptoms, and following a systematic troubleshooting approach, operators and maintenance personnel can quickly resolve the issue and minimize downtime. Regular maintenance and adherence to manufacturer guidelines are key to preventing such errors and ensuring the longevity of Jungheinrich machines.
Jungheinrich Error Code 1901 typically indicates a Startup Safety Violation, specifically that the drive pedal was already activated (pressed) when the truck was switched on or the startup sequence began. Quick Fix (The "Operator Error" Check) Turn the truck OFF. Ensure your feet are completely off the drive pedals. Ensure the directional switch is in Neutral. Turn the truck ON again. Detailed Troubleshooting Guide
If the error persists after a restart, the system likely detects a signal from the pedal even when it isn't being touched. 1. Physical Obstructions Jungheinrich Error Code 1901
Debris: Check under and around the drive pedal for debris (shrink wrap, wood chips, dirt) that might be preventing it from returning to its full "zero" position.
Sticking Pedal: Manually press and release the pedal to ensure it springs back smoothly. If it feels "crunchy" or slow, it may need cleaning or lubrication. 2. Sensor & Magnet Issues
Sensor Gap: On many Jungheinrich models, error 1901 can trigger if the sensor wheel is wobbling or the gap between the sensor and the sensor wheel is too large .
Calibration: The "zero point" of the potentiometer (the sensor that measures pedal depth) may have drifted. A technician using Jungheinrich JET Diagnostic Software can recalibrate the pedal travel. 3. Electrical Faults
Short Circuit: A short in the wiring harness between the pedal and the controller can send a false "pressed" signal.
Faulty Potentiometer: If the internal resistance of the pedal sensor is outside of the expected range, the controller will throw 1901 as a safety precaution to prevent the truck from jumping forward unexpectedly. Summary Table Resolution Pedal pressed during startup Restart with feet off the floor. Obstruction under pedal Clean area around the pedal base. Sensor/Magnet gap too wide Check for mechanical "play" or wobbling . Calibration drift Professional recalibration via service software . You will need: The specific feature triggered by
Note: If the code is accompanied by Error 70, it may indicate a deeper power supply issue behind the main contactor .
If you'd like, I can help you find a local Jungheinrich Service Center or provide the reset button combination for specific display models. Resetting Jungheinrich Service Codes | PDF - Scribd
The Jungheinrich Error Code indicates that the drive pedal was activated during startup
. This is a safety feature designed to prevent the forklift from moving unexpectedly when you turn it on. Machine Maxx USA Quick Fixes & Troubleshooting
If you see this code on your display, try the following steps to resolve it: Release the Pedal
: Ensure your foot is completely off the drive pedal before turning the key or starting the truck. Restart the Vehicle Most common causes (not a feature, but diagnostics):
: Switch the truck off, wait a few seconds, and then turn it back on without touching the pedal. Check for Obstructions
: Inspect the pedal area to make sure no debris or floor mats are holding the pedal down. Inspect the Pedal Sensor
: If the error persists even with the pedal released, there may be a fault with the pedal's potentiometer or return spring. Check the wiring connections to the drive pedal for any damage or loose plugs. Machine Maxx USA Error Code Breakdown
Jungheinrich uses a specific structure for their codes to help identify where the issue is occurring: First Digit (1) : Refers to the Gear/Travel component area. Second Digit (9) : Refers to or operation-related messages. Sub-index (.1)
: Provides specific detail, in this case, "activated during startup". Machine Maxx USA For more complex issues, you may need to use the Jungheinrich Operating Manuals Database to find the service manual for your specific serial number. Machineseeker Blog - or help you find a local service technician Jungheinrich Forklift Error Codes - Machine Maxx USA
1901.1 – Drive pedal activated during startup. drive pedal when the parking brake is not released. activated at the same time. Machine Maxx USA Jungheinrich Forklift Error Codes - Machine Maxx USA
* 1901.1 – Drive pedal activated during startup. * 2951.1 – Hydraulic function activated during startup. Machine Maxx USA Jungheinrich Forklift Truck Fault Codes DTC.pdf