As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUX PITOT LIGHT AFTER ENGINE START DURING TAXI OUT. GROUNDED - YES. PER B737-800 FIM 30-31 TASK 801. AUX PITOT HEATER C/B OUT, RESET, TRIED OPS CHECK. AFTER A FEW SECONDS LIGHT CAME BACK ON. C/B REMAINED IN. EXAMINED C/B. CHECK GOOD. AUX PITOT RESISTANCE CHECK FAILED. REMOVED AND REPLACED AUX PITOT PROBE IAW B737-800 AMM 34-11-01.