Possible causes

– Transmission temperature sensor harness is open or shorted
– Transmission temperature sensor circuit poor electrical connection
– Faulty transmission temperature sensor

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P1783 Description

Engine at operating temperature and the Engine Control Module (ECM) detected the transmission temperature sensor was over calibrated range

P1783 Information for specific makes

P1783 FORD
P1783 LINCOLN