If you are unable to clear the code by restarting the vehicle, you may need to consult the official Jungheinrich Operating Manuals Database for your specific model series. Machineseeker Blog - pedal voltage readings required for a technician to calibrate the potentiometer? Jungheinrich Forklift Error Codes - Machine Maxx USA
Without this accurate temperature data, the controller defaults into (reduced speed) or completely disables the drive motor to prevent thermal damage.
If you have performed all steps and code 1901 persists, contact a certified Jungheinrich technician – the traction controller may be faulty and requires dealer-level programming.
Only do this if you have confirmed good sensor, good wiring, and the controller still reads 5V fixed at its input. A used SEM controller can cost $800–$1500. Reprogramming via Jungheinrich dealer is mandatory. Jungheinrich Error Code 1901
The drive controller itself (often branded ZAPI, Curtis, or Jungheinrich house-branded) can develop internal faults:
If the code persists after a restart and physical inspection, the issue is likely a or a wiring harness failure . These require specialized diagnostic tools to calibrate or replace. You can refer to the Jungheinrich Operating Manuals Database0;4a1; 0;850; for series-specific electrical diagrams. 18;write_to_target_document7;default0;a76;18;write_to_target_document1a;_GxjuaaCCDKeP8L0P1LrdkAo_20;16;
: Turn the key to the 'Off' position, ensure the pedal is in its neutral position, and then turn the machine back on. If you are unable to clear the code
What is the of your Jungheinrich truck? (e.g., EFG, EJE, ETV)
Follow these steps in order. In most cases, the solution is simple and will require only a few seconds.
Here are the steps to troubleshoot and resolve the Jungheinrich error 1901, ordered from simplest to most complex. 1. The "Reset" Approach (Check Operator Error) If you have performed all steps and code
The controller detects input from the pedal, prevents startup, and displays "1901.1" on the screen. Common Causes of 1901.1
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Damaged wires or loose connections in the pedal sensor circuit, causing a false signal.
If you can tell me the (e.g., EFG, EJE), I can help you find a more specific guide for your equipment. Share public link
The cause of this error is almost always related to the truck's startup sequence, and it falls into three main categories: