Possible causes of Code P1290
- Faulty thermostat
- Overheated engine
- Low coolant level
- Defective cylinder head temperature (CHT) sensor
- Cylinder head temperature (CHT) sensor wiring is open or short-circuited
- Poor electrical connection in the cylinder head temperature (CHT) sensor circuit
How is Code P1290 repaired?
Start by checking the “Possible Causes” listed above. Visually inspect the wiring harness and associated connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
What are the possible symptoms of Code P1290?
- Check engine light on (or Service Engine Soon warning light)
What does Code P1290 mean?
The cylinder head temperature (CHT) sensor is mounted in the cylinder head wall 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°C (258°F), the PCM shuts off four fuel injectors at a time. The PCM will alternate the four disabled injectors every 32 engine cycles. The four cylinders that are not injected with fuel act as air pumps to help cool the engine. If the temperature exceeds 154°C (310°F), the PCM shuts off all fuel injectors until the engine temperature drops below 154°C (310°F).