As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA- FLIGHT 2531 - AFTER ENGINE START RECEIVED A APU BLEED CAUTION MESSAGE. RETURNED TO THE GATE. MAINTENANCE FOUND CODE MPE 46 IN THE MDC. REPLACED THE LOAD CONTROL VALVE IAW CRJ-700 AMM 49-51-05-000-801-A01. OPERATIONAL CHECKS GOOD. AIRCRAFT RETURNED TO SERVICE.