What was found
D: WHILE THE APU WAS RUNNING ON THE GROUND WITH BOTH #1 AND #2 ENGINES OFF THE #1 PACK SPIKED IN TEMPERATURE OF 99 DEGREES C AND FILLED THE COCKPIT AND CABIN WITH SMOKE. / C: MEL 21-51-1G / CAT: 'C' DUE 9/16/22 / WHILE THE APU WAS RUNNING ON THE GROUND WITH BOTH #1 AND #2 ENGINES OFF THE #1 PACK SPIKED IN TEMPERATURE OF 99 DEGREES C AND FILLED THE COCKPIT AND CABIN WITH SMOKE. (FLIGHT #3572 FILED CLOSED) SEP 06, 2022 STATION: SBN--DEFERRED LH PACK IAW CRJ 900 MEL 21-51-1G. NO MX ACTIONS REQUIRED. PLACARD INSTALLED. / SEP 07, 2022 STATION: DTW -- FOUND THE LH ACM SEIZED. REMOVED AND REPLACED THE LH ACM IN REFERENCE TO CRJ 900 AMM 21-51-08. OPS CHECK GOOD.