Cylinder Head Temperature Sensor Out of Self-Test Range
Table of contents
- Possible Causes
- How To Fix
- Tech Notes
- Cost To Diagnose
- When is the code detected
- Possible Symptoms
- Description
P1288 MERCURY 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
How do I fix code P1288 MERCURY?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- Indicates the Cylinder Head Temperature (CHT) sensor is out of Self-Test range. Engine is not at normal operating temperature.
Cost of diagnosing the P1288 MERCURY code
The cost of diagnosing the P1288 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the code detected
The P1288 code is set if the engine reaches critical temperature.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P1288 MERCURY 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°C (-258°F), 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 °C (310°F), the PCM disables all of the fuel injectors until the engine temperature drops below 154°C (310°F).