Engine-Codes - Mercury - P1288 MERCURY

P1288 MERCURY - Cylinder Head Temperature Sensor Out of Self-Test Range

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

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 is the P1288 MERCURY code repair?

Start by checking 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.

What is the cost to diagnose the P1288 MERCURY code

Labor: 1.0

The cost to diagnose the P1288 MERCURY code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. 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 Meaning

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).

More Information

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