Canon NP6621 Service Handbook page 128

SELF DIAGNOSIS
B. Self Diagnosis on the Cassette Feeding Unit
Code
E901
8–4
Cause
• Cassette feeding unit control-
ler (faulty)
• Cassette feeding unit motor
(faulty)
Description
• The motor clock signal is not detected
within 1 sec after the pedestal motor
drive signal has been generated.