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Curtis Code 69
External Supply Out of Range — controllers 1234 / 1236 / 1238

Possible causes (from the Curtis manual)

1. External load on the 5V and 12V supplies draws either too much or too little current. 2. Fault Checking Menu parameters Ext Supply Max and Ext Supply Min are mis-tuned. 3. See Monitor menu » Outputs: Ext Supply Current.

When it sets / how it clears

Set: The external supply current (combined current used by the 5V supply [pin 26] and 12V supply [pin 25]) is either greater than the upper current threshold or lower than the lower current threshold. The two thresholds are defined by the External Supply Max and External Supply Min parameter settings (page 52). Clear: Bring the external supply current within range.

Effect of the fault

None, unless a fault action is programmed in VCL.

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 69 with a Curtis controller, this entry applies; the vehicle maker’s manual may add model-specific notes.

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For controller, contactor, sensor or throttle parts, send us the code (Curtis 69), 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.