What does it mean?
P1592 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Barometric/Boost Pressure Signal Ratio out of Range .
Symptoms
- Check engine light on with the fault stored under load
- Loss of power and the engine dropping into limp mode
- Black smoke on acceleration and a strong smell from the exhaust on diesel engines
- Poor throttle response and higher fuel consumption
- Symptoms may be worse at altitude or in cold weather when the reference values diverge
- Boost gauge readings, where fitted, do not correspond to how the engine feels
Likely causes
- Boost or manifold pressure sensor fouled with soot and oil, which is very common on diesel engines
- Blocked, kinked or oil-filled pressure hose to the sensor
- Failed barometric pressure sensor, or a faulty internal barometric element in the module
- Boost leak at a hose clamp, intercooler pipe or charge air cooler, so measured pressure never matches expectation
- Intake air leak downstream of the sensor
- Corroded sensor connector or a damaged signal wire
- Sensor fitted with the wrong part number after a previous repair
How to fix it
- With the ignition on and the engine not running, compare the barometric and manifold pressure values; they should read almost the same
- Remove the pressure sensor and inspect the tip for soot, oil and water contamination
- Check the pressure hose for kinks, splits, blockage and oil accumulation, and clear or replace it
- Pressure test the charge air system for leaks at the pipes, clamps and intercooler
- Compare the sensor value with a known good gauge while raising engine load
- Clean or replace the sensor with the correct part number and clear the code
- Road test under load and confirm that measured boost tracks the commanded value