P2479: Ford exhaust-temperature sensor 2 high engineering-range fault

Ford's P2479 entry is exhaust-temperature sensor 2 out of range. In this documented monitor, out of range means the high side of the engineering temperature scale, typically 1,150°C. The code should not be broadened into a general electrical open/short diagnosis.

Keep three tests separate

The source lists P2032 and P2033 for sensor 2's electrical low/high checks, and it provides separate model and sensor-comparison rationality checks. P2479 belongs to the engineering-range test. The sensor transfer function prevents a unique low-side engineering threshold, so this monitor is not a two-direction temperature test.

Ford gives a two-second typical duration with key on and battery voltage between 9 and 16.25 volts. No six-hour soak is listed for this range check.

Preserve sensor identity

Identify sensor 2 from the correct exhaust configuration and retain its actual temperature data with any circuit or plausibility faults. A high interpreted temperature may require investigation of the measurement and system condition; the code alone does not separate them. The manual's generic sensor-use examples are not proof of one universal mounting location. Use safe hot-exhaust handling procedures during physical diagnosis.

Source and applicability

Ford 2015 model-year diesel OBD system operation summary, revision December 22, 2014; the cited monitor only, without blanket model or engine applicability. Ford source, physical PDF pages 128, 129. The documented monitor explains the fault decision; vehicle-specific service information is still needed for connector identification and a complete repair procedure.