Operation CHARM: Car repair manuals for everyone.

CHT Sensor

The CHT sensor:

^ is mounted into the wall of the cylinder head and is not connected to any coolant passages.
^ sends the PCM a signal indicating cylinder head temperature.

^ if the temperature exceeds approximately 121 °C (250°F), the PCM disables half of the fuel injectors at a time. The PCM will alternate which fuel injectors are disabled every 32 engine cycles. The cylinders that are not being fuel injected act as air pumps to aid in engine cooling.
^ if the temperature exceeds approximately 166°C (330°F), the PCM disables all of the fuel injectors until the engine temperature drops below approximately 1 54°C (31 0°F).