Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2018 Ford Fusion Energi TitaniumFACTORY OEM SERVICE PROCEDURE
DTC P128A - Cylinder Head Temperature Sensor Circuit Intermittent/Erratic
P128A - CYLINDER HEAD TEMPERATURE SENSOR CIRCUIT INTERMITTENT/ERRATIC
| Description: | This DTC sets when the CHT circuit is intermittently open or shorted while the engine is running. | ||
| Possible Causes: |
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| Diagnostic Aids: | Monitor the CHT PID on a scan tool. Look for sudden changes in the reading when the harness is wiggled or the sensor is tapped. | ||
| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | All GO to PINPOINT TEST DL . | ||
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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