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Curtis Code 17
Severe Undervoltage — controllers 1234 / 1236 / 1238

Possible causes (from the Curtis manual)

1. Battery Menu parameters are misadjusted. 2. Non-controller system drain on battery. 3. Battery resistance too high. 4. Battery disconnected while driving. 5. See Monitor menu » Battery: Capacitor Voltage. 6. Blown B+ fuse or main contactor did not close.

When it sets / how it clears

Set: Capacitor bank voltage dropped below the Severe Undervoltage limit (see page 55) with FET bridge enabled. Clear: Bring capacitor voltage above Severe Undervoltage limit. Curtis 1234/36/38 Manual, OS11

Effect of the fault

Reduced drive torque.

Curtis 1234/1236/1238 controllers are fitted to many electric forklifts and industrial trucks (including models from Chinese brands that use Curtis control). If your display shows code 17 with a Curtis controller, this entry applies; the vehicle maker’s manual may add model-specific notes.

Need the part?

For controller, contactor, sensor or throttle parts, send us the code (Curtis 17), controller model and vehicle model on WhatsApp — we quote genuine and OEM parts for export.

Source: Curtis 1234/36/38 Controller Manual, OS 11, Section 8 Diagnostics & Troubleshooting, Table 5. Compiled 2026-10-29. No affiliation with Curtis Instruments.