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DTC 421: Control Module Fault

  1. This DTC will set if seat control module main relay is not activated when a seat switch button is pressed or if main relay is activated when no seat switch button is pressed. To correct this problem, turn ignition off.
  2. Clear DTCs. See SELF-DIAGNOSTIC SYSTEM  . Move seat using control buttons. Recheck DTCs. If DTC 421 resets, replace seat control module. See SEAT CONTROL MODULE  under REMOVAL & INSTALLATION. If DTC 421 does not reset, DTC could be caused by a temporary fault, no further action is necessary.
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