Originally replaced the throttle pot which didn't help. On a guess, replaced the controller which also didn't help. Voltages are all as per the manual and the pot is set up correctly. Every time the throttle voltage hits 2.5V, the code appears no matter where the pot is set when closed.
Jumper wire is in place at 9 & 16, throttle calibration has passed numerous times. Continuity on all wires tests perfect.
The manual shows no other possible causes of a code 21.
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