Temperature sensor fault: gas furnace codes by brand

A temperature sensor reading is missing or out of range.

Brand	Code	Meaning	What you can do
Carrier	51.1	Outdoor air sensor open	Call a pro
Carrier	51.2	Outdoor air sensor shorted	Call a pro
Carrier	52.1	Supply air sensor open	Call a pro
Carrier	52.2	Supply air sensor shorted	Call a pro
Carrier	53.1	Return air sensor open	Call a pro
Carrier	53.2	Return air sensor shorted	Call a pro
Goodman	E1A	Onboard return air sensor shorted	Call a pro
Goodman	E15	External return air sensor circuit open	Call a pro
Goodman	E16	External return air sensor circuit shorted	Call a pro
Goodman	E17	Supply air sensor circuit open	Call a pro
Goodman	E18	Supply air sensor circuit shorted	Call a pro
Goodman	E19	Onboard return air sensor unplugged	Call a pro