As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WITH ANTI-ICE ON, RECEIVED WING ANTI-ICE LT DISAGREE. LT ANTI-ICE VLV SHOWED DISAGREE ON SYNOPTIC & BLEED PRESS ON SYS 1 WENT TO ZERO. SECURED ANTI-ICE IAW QRH & BLEED PRESS RETURNED TO NORMAL. DIVERTED AND LANDED MSP WITHOUT INCIDENT. REMOVED AND REPLACED L ANTI-ICE PRESS DIFF SWITCH REF M/M 30-11-02-4 AND PERFORMED WING ANTI-ICE ADJ/TEST REF M/M 30-11-00-5. CHECKS GOOD, A/C OK FOR SERVICE.