DTC P1127: Ho2S Heater

DTC indicates that HO2S heater was not on during KOER SELF-TEST and testing of HO2S did not occur. Possible cause is cool exhaust system. Connect scan tool to DLC. Using scan tool, access all HO2S heater PIDs. If all PIDs indicate ON, repeat quick test. See QUICK TEST in TESTS W/CODES - INTRODUCTION article. If any PIDs indicate OFF, operate engine until all PIDs are on. Repeat quick test.