P1289 Code: Meaning, Causes, and Symptoms | OBD2 Codes

P1289 – Cylinder Head Temperature Sensor Signal Greater Than Self-Test Range

 

P1289 Possible Symptoms

 

Engine Light ON (or Service Engine Soon Warning Light)

 

P1289 Possible Causes

 

Wrong thermostat,Engine overheated,Low engine coolant level,Faulty Cylinder Head Temperature (CHT) sensor,Cylinder Head Temperature (CHT) sensor harness is open or shorted,Cylinder Head Temperature (CHT) sensor circuit poor electrical connection

 

P1289 Description

 

The Cylinder Head Temperature (CHT) Sensor is mounted into the wall of the cylinder head and is not connected to any coolant passages. The CHT sends a signal to the Powertrain Control Module (PCM) indicating the cylinder head temperature. If the temperature exceeds 126?? (-258??), the PCM disables four fuel injectors at a time. The PCM will alternate which four injectors are disabled every 32 engine cycles. The four cylinders that are not being fuel injected act as air pumps to aid in cooling the engine. If the temperature exceeds 154 ?? (310??), the PCM disables all of the fuel injectors until the engine temperature drops below 154?? (310??).