B1257 Code: Meaning, Causes, and Symptoms | OBD2 Codes

B1257 – Air Temperature External Sensor Circuit Short To Ground

 

B1257 Possible Symptoms

 

Engine Light ON (or Service Engine Soon Warning Light)

 

B1257 Possible Causes

 

Faulty Air Temperature External Sensor,Air Temperature External Sensor harness is open or shorted,Air Temperature External Sensor circuit poor electrical connection

 

B1257 Description

 

The Powertrain Control Module (PCM) monitors the Air Temperature External Sensor. The PCM sets the OBDII code when the Air Temperature External Sensor is not to factory specifications.