"The steering sensor works on the CAN-Open protocol," Ray narrated, mostly to himself, though Elias was listening intently from the cabin. "It’s a communication network. If one wire is loose, or if there's electrical noise, the signal drops out. The controller waited for a confirmation signal, didn't get it, and timed out. Code 1901."

The vast majority of Error 1901 occurrences are simply due to the operator's foot resting on the accelerator pedal while turning the key or pressing the start button. Alternatively, a floor mat or debris could be pressing against the pedal without the operator noticing.

: 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

Test the Gas Pulse Generator (Potentiometer)The 1901 code can be triggered by a faulty "gas" sensor—the component that tells the truck how fast you want to go. If the sensor sends a signal that is out of the expected voltage range, the controller will reject the data. Using a multimeter, a technician can check if the sensor is providing a smooth, linear voltage transition when the butterfly tabs are rotated.

The potentiometer or Hall effect sensor that measures pedal position is out of alignment, causing it to send a "pressed" signal even when it is not.

If the code is accompanied by Error 70 , it may indicate a deeper power supply issue behind the main contactor .