P0470: Ford 6.0L exhaust pressure is implausibly high before running

P0470 has a broad exhaust-pressure sensor title. In Ford's 2004 6.0L diesel monitor, it is a functional check performed with the engine off or cranking. Exhaust pressure above 150 kPa absolute for more than five seconds is the stated failure condition.

The engine state changes the interpretation

A pressure that may need different interpretation during loaded running can be implausible before the engine is operating normally. Preserve the off or cranking state with the pressure reading. This monitor should not be replaced by a running exhaust-pressure test simply because both use the same sensor.

Ford lists acceptable exhaust-pressure and EGR-position sensor status as prerequisites. Electrical range faults P0472 and P0473 are separate checks; P0470 addresses the functional value in this operating state.

Keep the pressure reference explicit

The threshold is absolute pressure. It is not 150 kPa above atmosphere, and the distinction matters when comparing scan-tool units. The code alone does not identify a plugged exhaust component or a failed sensor. Use the correct plausibility and pressure-sensor diagnostic procedure to distinguish an inaccurate measurement from an abnormal physical condition, without opening hot or pressurized exhaust connections as an improvised test.

Source and applicability

Ford 2004 model-year 6.0L diesel OBD summary, revision August 7, 2003; the cited monitor and transmission implementation only. Ford source, physical PDF page 18. The documented monitor explains the fault decision; vehicle-specific service information is still needed for connector identification and a complete repair procedure.