Jungheinrich Error Code 1901 Info

The symptoms associated with Error Code 1901 can vary but often include:

Unlike generic OBD codes, Jungheinrich uses proprietary manufacturer-specific codes. Error Code 1901 generally translates to:

"Drive Motor Temperature Sensor – Plausibility Error"

In plain English: The main traction control unit (typically the SEM or ELV controller) has detected an electrical signal from the drive motor’s temperature sensor that is either out of range or contradictory to expected values.

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 is a safety-related event message that occurs when the drive (accelerator) pedal is activated during the forklift's startup sequence. Meaning and Cause

This code is part of the "operator error" or "standard event" category (specifically codes ranging from 1 to 50 in some systems). It is triggered by a safety feature designed to prevent the truck from moving unexpectedly as soon as it is switched on.

Primary Cause: The accelerator pedal was already pressed down when the ignition key was turned or the truck was started.

Secondary Cause: A mechanical issue where the pedal is stuck in an "on" position or a faulty sensor is incorrectly signaling that the pedal is pressed. Recommended Actions Jungheinrich Error Code 1901

Release the Pedal: Fully release the accelerator pedal to its neutral position.

Restart the Truck: Switch the forklift off and then back on again.

Check for Obstructions: Ensure there is no debris or floor mat preventing the pedal from returning to the neutral position.

Direction Selection: Ensure no travel direction (forward or reverse) is selected during startup if the model requires neutral for initialization.

If the error persists after releasing the pedal and restarting, it may indicate a faulty accelerator sensor or a calibration issue with the drive controller, requiring professional service. Jungheinrich Forklift Error Codes - Machine Maxx USA

Jungheinrich Forklift Error Codes - Machine Maxx USA. * 0915.2 – Industrial truck not ready for operation – battery door opened. * Machine Maxx USA Jungheinrich Error Code List - Google Groups

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 The symptoms associated with Error Code 1901 can

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

: 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 "Drive Motor Temperature Sensor – Plausibility Error"

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

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):

After a software update or component replacement, if the main controller firmware is not compatible with the drive controller firmware version, communication handshake fails intermittently, triggering 1901.

⚠️ Safety note: Always disconnect the battery before unplugging controllers. Capacitors in the drive controller can hold dangerous voltage for up to 5 minutes after key-off.

If error 1901 appears after controller replacement, perform a "CAN bus reset" via the service menu (Code 5 – CAN Reset).

No. Installing a fixed resistor (e.g., 2.5kΩ) will fool the controller into thinking the motor is always at 20°C. The motor will overheat without protection, leading to melted windings and a $3000 repair.